TWI577065B - Organic electroluminescent elements - Google Patents

Description

Organic electroluminescent element

The present invention relates to an organic electroluminescence device, and more specifically to an organic electroluminescence device comprising a light-emitting layer which is liquid at normal temperature.

An organic electroluminescence device (organic light-emitting device, hereinafter referred to as an organic EL device) has a structure in which an organic layer (light-emitting layer) containing a film of at least one type of luminescent organic compound is interposed between a cathode and an anode, and the film is injected. ‧ An element that transports electrons and positive holes, recombines them to generate excitons, and emits light by the light emitted by the excitons when they are inactivated (fluorescent ray).

Since the organic EL device uses a light-emitting organic compound in a light-emitting element of a light-emitting layer, it is lightweight and flexible, and thus it is expected to be applied to a display which is inexpensive and capable of displaying a large-area full-color display.

The light-emitting layer used in the organic EL device is a process in which the carrier (charge) of the positive hole and the electron is transported, the recombination of the carriers causes the formation of the excitons, and the light is emitted. drive.

Therefore, it is necessary to have a material having these three functions in the light-emitting layer. Usually, the material is a carrier-transmitting luminescent material capable of exhibiting these three functions, or a carrier for mixing a plurality of organic substances in order to complement the three functions. Transport material / luminescent material.

When the carrier transport material/light-emitting material is used for the light-emitting layer, the light-emitting material is diluted by the carrier transport material, and thus the concentration extinction is suppressed, and an organic EL element having high light-emitting efficiency can be expected. Therefore, research on various combinations of luminescent materials and carrier transport materials is underway.

Incidentally, the luminescent material for the luminescent layer is not simply a substance having a desired fluorescent wavelength and a high quantum yield, and it is necessary to select a carrier transporting material suitable for a specific fluorescent pigment. The reason for this is because the carriers transported into the carrier transport material recombine, and the generated excitation energy causes the luminescence of the fluorescent pigment doped in the carrier transport material.

Therefore, the correlation of the HOMO/LUMO energy levels of the components in the luminescent material/carrier transport material, or the combination of these efficient energy shifts, has gradually become an improvement in the driving or luminous efficiency of the components. The subject that must be explored.

Further, in addition to the selection of the luminescent material and the carrier transport material, a means for separating the material for injecting, transporting, and recombining the carrier into a plurality of layers may be employed as means for achieving high luminous efficiency of the organic EL element.

This is a functionally-separated thin film laminated organic EL element (hereinafter referred to as a thin film laminated organic EL element) which was reported by the Kodak company's Tang et al. in 1987, and has several layers having a cathode/electron at present. Development of thin-film laminated organic EL elements bonded to each other, such as injection layer/electron transport layer/positive hole barrier layer/light-emitting layer/electron barrier layer/positive hole transport layer/positive hole injection layer/anode Ongoing.

In the film-layered organic EL device, it is necessary to deposit a plurality of layers of materials having respective functions. Therefore, from the viewpoint of procedural convenience, the method for producing a thin film laminated organic EL device is studied by The vapor deposition process performed by the wet process is the mainstream, and Patent Document 1 discloses a hole barrier layer capable of performing a wet process by forming titanium oxide between the light-emitting layer and the cathode. The leakage current generated by the leakage of the hole to the cathode is reduced, and high luminance or luminous efficiency can be obtained.

There is also a method different from the thin film laminated organic EL element. As disclosed in Non-Patent Document 1, a light-emitting element is reported, and by adding an organic salt to the polymer light-emitting material to enhance the injection efficiency of the carrier, A low driving voltage and high luminance can be obtained.

On the other hand, in addition to the study of improving the characteristics of the organic EL element, the occurrence of a deterioration phenomenon called burn-in of the element has become one of important subjects. This phenomenon is considered to be caused by a voltage applied to the organic EL element for a long period of time, and the impurities cause decomposition or denaturation of the material constituting the organic EL element.

In order to prevent this deterioration, it is necessary to remove moisture, oxygen, or a small amount of impurities contained in the organic film formed on the surface of the electrode.

The specific method can be a method of improving the purity and stability of the organic material constituting the organic EL element, or sealing the desiccant or the like in order to prevent oxygen and moisture from being mixed from the outside.

However, from a practical point of view, the lifetime of the organic EL element must be at least 100,000 hours at 100 cd/m ² , during which the decomposition of the organic substance or the generated impurities cause deterioration of the element, which is unavoidable.

In the above-described existing organic EL device, the burning of the organic layers causes deterioration of the device, and if one of the plurality of organic layers constituting the organic EL device is deteriorated, the lifetime of the entire device is greatly affected. .

If the deteriorated organic layer is formed, for example, by a cassette or the like, the new organic layer can be continuously supplied, and as a result, it is considered that the organic EL element can be driven semi-permanently.

However, almost all of the above-mentioned existing organic EL elements use a solid organic film, and it is extremely difficult to replace only the deteriorated organic layer.

In recent years, a related art for solving the above problems has been gradually developed. For example, Non-Patent Document 2 discloses an organic EL element that liquefies a light-emitting layer. By liquefying or semi-curing the light-emitting layer, the deteriorated liquid light-emitting layer can be said to be easier to replace than the solid film layer, and is considered to be a light-emitting element capable of at least replacing the light-emitting layer.

However, the organic EL element which liquefies the light-emitting layer disclosed in Non-Patent Document 2 is hardly an organic EL element which exhibits excellent characteristics which can replace the existing illumination or display, and the liquid light-emitting layer or Component construction is still necessary to optimize.

Further, the element structure in Non-Patent Document 1 is a relatively simple article set as a cathode/light-emitting layer/positive hole injection layer/anode, and as described above, it is necessary to improve the film-layered type in order to enhance the organic EL characteristics. Organic EL construction, while still leaving room for development.

Prior technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-261576

Non-patent literature

Non-Patent Document 1: Synthetic Metals, 123, 207 (2001)

Non-Patent Document 2: Appl. Phys. Lett., 95, 053304 (2009)

The present invention has been made in view of such circumstances, and an object of the invention is to provide an organic EL device having a liquid-like light-emitting layer and capable of improving EL characteristics such as driving voltage, luminance, current density, and external light-emitting efficiency.

The present inventors have found that a light-emitting layer which is liquid at a normal temperature and which can maintain a liquid state during both driving and non-driving, and an organic electroluminescence element (organic EL element) having such a light-emitting layer has been reported (PCT/ JP 2010/062225) However, as described in the above-mentioned Non-Patent Document 2, the organic EL element has room for further improvement in terms of EL characteristics.

Then, in order to further improve the EL characteristics of the organic EL element having the liquid-emitting layer, the present inventors have found that by adding an ionic material to the light-emitting layer, it is possible to obtain a high luminance. The present invention has been completed by an organic electroluminescence device (organic EL device) having a low driving voltage and high luminous efficiency.

That is, the present invention provides:

An organic electroluminescence device comprising: an anode, a cathode, and a light-emitting layer interposed between the electrodes and at a normal temperature, wherein the light-emitting layer contains an ionic material,

2. The organic electroluminescence device according to Item 1, wherein the luminescent layer is composed of a material having a carrier transporting ability and an illuminating ability, and an ionic material.

3. The organic electroluminescence device according to Item 1, wherein the luminescent layer is composed of a carrier transport material, a luminescent material, and an ionic material.

4. The organic electroluminescent device according to Item 3, wherein the ionic material is selected from the group consisting of a liquid organic salt, a liquid inorganic salt, an organic salt dispersible in a liquid carrier transport material or a liquid luminescent material, and One or more kinds of inorganic salts dispersed in a liquid carrier transport material or a liquid luminescent material,

5. The organic electroluminescence device according to any one of items 1 to 4, wherein the ionic material contains the compound represented by the formula [1]:

(A ⁿ⁺ ) _i (B ^m- ) _j [1]

[wherein, A ⁿ⁺ is a cation component of n (n represents an integer of 1 to 10), and represents a metal ion or a cerium ion containing a nitrogen atom, a phosphorus atom, a sulfur atom, or an oxygen atom, and B ^m- is m (m represents The anion component of the valence of 1 to 10 represents a halide ion, an oxyacid anion, an anion containing a boron atom, an anion containing a phosphorus atom, and an anthranilide anion. i and j are each an integer of 1 to 100, and the ionic material represented by the formula [1] is an electrically neutral integer].

The organic electroluminescence device according to any one of the items 1 to 5, wherein the luminescent material contains 0.01 to 50% by mass of the ionic material,

The organic electroluminescence device according to any one of the items 1 to 6, further comprising a functional separation type film structure comprising at least three functional layers including the light-emitting layer,

8. The organic electroluminescence device according to any one of items 1 to 7, wherein a hole blocking layer interposed between the cathode and the light-emitting layer is used as the functional layer,

9. The organic electroluminescent device according to Item 8, wherein the hole blocking layer contains a metal oxide, a metal nitride, a metal sulfide, a metal oxynitride, a polymer compound,

10. The organic electroluminescent device according to Item 9, wherein the hole blocking layer is one or more selected from the group consisting of oxides, nitrides, sulfides and oxynitrides of a metal element, and the metal element is selected from the group consisting of At least one of metal elements of Ti, Zr, Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, and Sb.

According to the present invention, there is provided an organic electroluminescence device which has a low driving voltage, high luminance and EL external quantum efficiency, exhibits excellent luminescence characteristics, and has a liquid luminescent layer.

In the organic electroluminescence device, the light-emitting layer can be maintained in a liquid state during driving and non-driving. Therefore, it is also possible to set a configuration in which only the light-emitting layer is replaced when the light-emitting layer is deteriorated (for example, jamming, extraction by recirculation, and re-injection).

Further, since the light-emitting layer is a liquid, an element can be manufactured using a coating process, and therefore, it can be applied to a large-area illumination element.

Further, it is also possible to produce a display element having a higher flexibility than an organic EL element composed of an existing solid organic film.

The invention is further described in detail below.

The organic electroluminescence device according to the present invention comprises an anode, a cathode, and a light-emitting layer interposed between the electrodes and at a normal temperature, and the light-emitting layer contains an ionic material.

Here, the normal temperature means a range of 20 ° C ± 15 ° C (5 to 35 ° C) prescribed in JIS Z 8703.

The liquid light-emitting layer may have a liquid property as long as the light-emitting layer as a whole, and at least one of the carrier transport material and the light-emitting material which can be used as the light-emitting layer constituent material is a liquid, and the composition constituting the light-emitting layer as a whole is It is a liquid object.

In addition, depending on the substance, it may not be possible to clearly separate the two functions of carrier transport ability and luminescence ability, for example, among carbazole, triarylamine, carbon condensed ring-based pigment, etc. A substance that has both functions.

In the present invention, a substance having both functions can be used as long as the entire light-emitting layer exhibits the characteristics of the liquid, and it can be used alone as long as it exhibits a liquid state.

In the present invention, the liquid carrier transport material is suitably a compound represented by the formula (1).

[Chemical 1]

X-Y (1)

Here, X is a charge transporting portion, and represents carbazole, triazole, imidazole, oxadiazole, 2,5-diphenyl-1,3,4-oxadiazole, arylcycloalkane, triarylamine, benzene. Diamine, hydrazine, oxazole, triphenylmethane, pyrazoline compound, hydrazine, fluorenone, polyaniline, decane, pyrrole, fluorene, ruthenium, quinophthalone, triphenylphosphine oxide, anthracene derivative, thick four Carbon condensed ring-based pigments such as benzene derivatives, anthracene derivatives, erythroprene derivatives, decacycloolefin derivatives, anthracene derivatives, metal or non-metal phthalocyanine, metal or non-metal naphthoquinone, benzidine .

From the standpoint of excellent positive hole transport performance, carbazole is preferred among these.

On the other hand, Y represents an alkyl group having 1 to 30 carbon atoms which may be bonded to at least one substituent of the charge transporting portion X and may contain an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond. Further, the ether bond, the thioether bond, the ester bond, the carbonate bond, and the guanamine bond may be present in the joint portion of X and Y (in this regard, Z described later is also the same).

In this case, the alkyl group may be any of a straight chain, a branch, and a ring, and it is considered that when a linear alkyl group is used, the intermolecular interaction such as the accumulation of the alkyl chains may enhance the crystallinity or The viscosity is increased, so that a branched alkyl group is preferred.

Specific examples of such an alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, c-propyl group, n-butyl group, isobutyl group, second butyl group and third butyl group. Base, c-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, c-pentyl , 2-methyl-c-butyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, c-hexyl, 1-methyl-c-pentyl, 1-ethyl-c-butyl, 1,2-dimethyl-c-butyl, N-heptyl, n-octyl, 2-ethylhexyl, n-decyl, n-decyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n. Base, positive seventeen base, positive eighteen base, positive nineteen base, positive twenty base, and so on.

The alkyl group having 1 to 30 carbon atoms, which has an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond, may be a group having such a bond at any position of the alkyl group as described above, specifically The substituents as described below can be mentioned.

In the present invention, in particular, a carrier transporting material which uniformly dissolves an ionic material can be obtained by using an alkyl group having an ether bond of 1 to 30 carbon atoms.

Specific examples of the above alkyl group having an ether bond include CH ₂ OCH ₃ , CH ₂ OCH ₂ CH ₃ , CH ₂ O(CH ₂ ) ₂ CH ₃ , CH ₂ OCH(CH ₃ ) ₂ , CH ₂ O (CH _{2 3} CH ₃ , CH ₂ OCH ₂ CH(CH ₃ ) ₂ , CH ₂ OC(CH ₃ ) ₃ , CH ₂ O(CH ₂ ) ₄ CH ₃ , CH ₂ OCH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ OCH ₂ CH(CH ₃ )CH ₃ , CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ OC(CH ₃ ) ₂ CH ₃ , CH ₂ OCH(CH ₃ )(CH _{2 3} CH ₃ , CH ₂ O(CH ₂ ) ₅ CH ₃ , CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , CH ₂ O(CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ , CH ₃ , CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ O(CH ₂ ) ₆ CH ₃ , CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ O(CH ₂ ) ₁₄ CH ₃ , CH ₂ O(CH ₂ ) ₁₅ CH ₃ , CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ O(CH ₂ ) ₁₈ CH ₃ , CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ OCH (CH ₃ ) ₂ , CH ₂ CH ₂ O(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , CH ₂ CH ₂ OC(CH ₃ ) ₃ , CH ₂ CH ₂ O(CH ₂ ) ₄ CH ₃ , CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ ) CH ₃ , CH ₂ CH ₂ OC(CH ₃ ) ₂ CH ₃ , CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₃ ) ₂ CH ₃ , CH ₂ CH ₂ OCH(CH ₂ CH ₃ )( CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₄ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₅ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₈ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OCH(CH ₃ ) ₂ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₄ CH ₃ , CH ₂ CH ₂ CH ₂ OCH (CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , CH ₂ CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH (CH ₃ )CH ₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ ,CH ₂ CH ₂ CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )C H ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₄ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₅ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₈ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ group or the like, or a group represented by the following formula.

[Chemical 2]

[Chemical 3]

Specific examples of the alkyl group having a thioether bond include a group in which an oxygen atom (O) of the alkyl group having an ether bond is substituted with a sulfur atom (S).

Specific examples of the alkyl group having an ester bond include a group in which an oxygen atom (O) of the above-mentioned ether bond-containing alkyl group is substituted with a C(O)O or OC(O) group.

Specific examples of the alkyl group having a carbonate bond include a group in which an oxygen atom (O) of the above-mentioned ether bond-containing alkyl group is substituted with OC(O)O.

Specific examples of the alkyl group having 1 to 30 carbon atoms of the guanamine bond include a group in which the oxygen atom (O) of the ether group-containing alkyl group is substituted with C(O)NH or NHC(O).

From the viewpoint of easily becoming a liquid, among these, a substituent having 6 to 30 carbon atoms is preferable, specifically, c-hexyl, 1-methyl-c-pentyl, 1-ethyl-c -butyl, 1,2-dimethyl-c-butyl, n-heptyl, n-octyl, 2-ethylhexyl, n-decyl, n-decyl, n-decyl, n-dodeyl, positive tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl group, n-eicosyl _{group, CH 2 O (CH 2)} 5 CH 3, CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , CH ₂ O(CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ ,CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ O(CH ₂ ) ₆ CH ₃ , CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ O(CH ₂ ) ₁₄ CH ₃ , CH ₂ O(CH ₂ ) ₁₅ CH ₃ , CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ O(CH ₂ ) ₁₈ CH ₃ , CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ CH ₂ CH ₂ O( CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ ,CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ CH ₂ OCH ₂ CH (CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ CH ₂ O (CH _{2 14} CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₅ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ CH ₂ O ( CH ₂ ) ₁₈ CH ₃ , CH ₂ CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , CH ₂ CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₃ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OCH (CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ , CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ )CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ ,CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₄ CH ₃ , CH ₂ CH ₂ CH ₂ O ( CH ₂ ) ₁₅ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₇ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₈ CH ₃ , CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₉ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ group, etc. The oxygen atom (O) of the group is replaced by a group of a sulfur atom (S), replaced with a group of C(O)O or OC(O), replaced with a group of OC(O)O, and substituted for C. (O) The base of NH or NHC (O) is suitable.

Preferred is CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ ,CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ C H ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ group or the like.

Suitable carrier transport materials include, for example, the following carbazole (X1), N,N-disubstituted or N,N,N-trisubstituted arylamine (X2).

[Chemical 4]

In the above formula, Y ¹ to Y ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms such as an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond (however, Y) At least one of ¹ to Y ³ and at least one of Y ⁴ to Y ⁶ are the above alkyl groups; and A ¹ and A ² represent a single bond or a substituted or unsubstituted aromatic ring.

Here, the term "alkyl" includes a linear, branched, cyclic alkyl group such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a 2-ethylhexyl group, or a cyclohexyl group, which is equivalent. The specific example and suitable for the functional group (Y) which lowers the melting point of the above general formula (1) are as described above.

Examples of the aromatic ring include a benzene ring and a naphthalene ring.

In the present invention, in order to prevent an increase in viscosity due to an increase in molecular weight, it is preferred that Y ¹ , Y ² , Y ⁴ and Y ⁵ are hydrogen atoms, and Y ³ and Y ⁶ are alkyl groups, and further, A ^1. A ² is preferably a benzene ring or a single bond.

From these viewpoints, the following compound (X3) is preferred, and the compound (3) is preferred, and the compound (4) or the compound (5) is more preferred, but is not limited thereto.

[Chemical 5]

[Chemical 6]

(wherein Y ³ represents the same meaning as described above).

[Chemistry 7]

It is also suitable to use the compounds represented below.

[化8]

(wherein Y ⁴ to Y ¹¹ are each independently, and represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms such as an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond (however, Y ^{4 )} At least one of Y ⁶ , at least one of Y ⁷ and Y ⁸ , and at least one of Y ⁹ to Y ¹¹ are the above alkyl group)).

[Chemistry 9]

(wherein R ¹ to R ^{4 are} independent of each other and represent an alkyl group having 1 to 30 carbon atoms).

[化10]

Further, in the case where a luminescent material to be described later is a liquid material, the carrier transporting material may be a substance which is solid at normal temperature on the premise that the material constituting the luminescent layer is a liquid as a whole.

Such a carrier transporting material may be appropriately selected from conventionally known materials, and examples thereof include (triphenylamine) dimer derivative (TPD) and (α-naphthyldiphenylamine) dimer (α-NPD). , [(triphenylamine) dimer] helical dimer (Spiro-TAD) and other triarylamines, 4,4',4",-para [3-methylphenyl (phenyl)amino] Star-radioamines such as triphenylamine (m-MTDATA), 4,4', 4", - gin[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA); 5,5',- Bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2',:5',2"trithiophene (BMA-3T) and other oligothiophenes, polyvinylcarbazole Positive hole transport material; Alq ₃ , BAlq, DPVBi, (2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole) (PBD An electron transporting material such as a triazole derivative (TAZ), a Bathocuproine (BCP), or a silole derivative.

Another material constituting the light-emitting layer of the present invention is a light-emitting material, and as long as it is appropriately selected from known substances, for example, an anthracene derivative, a thick tetraphenyl derivative, an anthracene derivative, a red fluorene derivative, or the like can be used. a carbon condensed ring-based pigment such as a decacycloolefin derivative; an anthracene derivative such as quinone diimide; a dibenzopyranose-based dye such as rose red B; a cyanine-based pigment; a coumarin 6 or a C545T-like cocoa Prime pigment; quinophthalone dye such as Qd4 or DEQ; squaraine dye; styrene based dye; pyrazolone derivative; phenoxazine dye such as NileRed; carbazole; triarylamine; (2-phenylpyridine) ruthenium (III) (Ir(ppy) ₃ ), gin [2-phenyl-4-(2-ethylcyclohexyloxy) pyridine] ruthenium (III) (Ir(ehppy) ₃ Equivalent complex; aluminum quinolol complex, benzoquinolinate yttrium complex, benzoxazolyl zinc complex, benzothiazole zinc complex, azomethyl zinc a central metal formed of a rare earth metal such as Al, Zn, Be or Tb, Eu, Dy, etc., an oxadiazole, a thiadiazole, a phenylpyridine, or a phenylbenzene. Imidazole, quinoline structure, etc. The metal constituting the seat complexes and the like.

From the viewpoint of excellent luminous efficiency, among these, a erythrin derivative is preferred.

Further, in the present invention, a liquid compound represented by the formula (2) can also be used as the luminescent material.

[11]

Z-W (2)

Here, Z is a dye moiety, and represents a carbon condensed ring-based dye, an anthracene derivative, a dibenzopyran-based dye, a cyanine-based dye, a coumarin dye, a quinophthalone dye, or a squaraine crystal. Pigment, styrene-based dye, pyrazolone derivative, phenoxazine-based dye, carbazole, triarylamine, ruthenium complex, central metal formed from Al, Zn, Be or rare earth metals a metal complex composed of a position, W is at least one substituent bonded to the dye portion Z, and represents a carbon number of 1 to 30 which may contain an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond. Alkyl group.

Specific examples of the dye portion and the alkyl group include the same as described above.

Suitable examples of Z include a carbon ring-cut dye, particularly a fluorene oxide derivative and an anthracene derivative. Suitable examples of W include an alkyl group having 1 to 30 carbon atoms, particularly an alkyl group having 6 to 30 carbon atoms.

Specific examples of the luminescent material include the following hydrazine derivative (Z1), which is a carbon condensed ring-based dye having excellent luminescent properties.

[化12]

In the above formula, W ¹ to W ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 30 carbon atoms such as an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond (however, W At least one of ¹ to W ⁴ is the above alkyl group; and A ¹ to A ⁴ represent a single bond or a substituted or unsubstituted aromatic ring. Here, specific examples of the alkyl group include the same as those of the above Y, and specific examples of the aromatic ring include the same as described above.

In order to prevent the viscosity from increasing as the molecular weight increases, it is preferable in this case that a substance having a single bond of A ¹ to A ⁴ is used, that is, W ¹ to W ⁴ are a compound directly bonded to a carbon condensed ring ( Further, Z2) is preferable. Further, a substance in which at least one of W ¹ to W ⁴ is a hydrogen atom is preferable, and among them, a substance in which three of them are hydrogen atoms is preferable.

From these viewpoints, the following compound (Z3) is preferred, but is not limited thereto.

[Chemistry 13]

[Chemistry 14]

The compound represented by the above (Z1) to (Z3) can also be used as a liquid luminescent material to form an organic EL device having a light-emitting layer which is not a host guest system.

Further, in the case where the carrier transport material is a liquid, the luminescent material may be a substance which is solid at normal temperature on the premise that the material constituting the luminescent layer is a liquid as a whole.

Such a light-emitting material may be appropriately selected from conventionally known materials, and examples thereof include argon (8-hydroxyquinoline) aluminum (III) (Alq ₃ ) and bis(8-hydroxyquinoline) zinc (II) (Znq). ₂ ), bis(2-methyl-8-hydroxyquinoline) (p-phenolate) aluminum (III) (BAlq), 4,4'-bis(2,2-distyryl)biphenyl (DPVBi) Wait.

The blending ratio of the carrier transport material and the light-emitting material is not particularly limited as long as the entire composition becomes a liquid, and can be determined as a carrier transport material by mass ratio: luminescent material = 99.99: 0.01 to 50 : 50 or so, and 99:1 is better.

In the organic electroluminescence device of the present invention, the ionic material used together with the liquid luminescent material is not particularly limited as long as it is an ionic material, and may be appropriately selected to be dissolved or dispersed in the liquid luminescent material. The ionic material of at least one of the carrier transport materials may be used.

Specific examples thereof include compounds represented by the following formula [1].

(A ⁿ⁺ ) _i (B ^m- ) _j [1]

In the above formula, A ⁿ⁺ is a cation component of n (n represents an integer of 1 to 10), and represents a metal ion; or a cerium ion containing a nitrogen atom, a phosphorus atom, a sulfur atom or an oxygen atom, and B ^m- is m (m) The anion component having a valence of 1 to 10 represents a halide ion, an oxo acid anion, an anion containing a boron atom, an anion containing a phosphorus atom, and an anthraquinone anion. i and j are each an integer of 1 to 100, and the ionic material represented by the formula [1] is an electrically neutral integer.

Examples of the ruthenium ion containing a nitrogen atom include a tetraalkylammonium cation, a tetraethylammonium cation, a tetrakis(n-butyl)ammonium cation, and a tetraalkylammonium such as a 1-(n-butyl)-1-methylpyrrolidinium cation. N,N'-dimethylimidazolinium cation, N,N'-ethylmethylimidazolinium cation, N,N'-butylmethylimidazolinium cation, etc. N,N'-dialkylimidazole A porphyrin cation or the like.

Phosphorus atom-containing onium ion include tetramethylphosphonium cation, tetraethylphosphonium cation, tetra (n-butyl) phosphonium cation tetraalkylphosphonium cation; PH ₄ ⁺ and the like.

Examples of the ruthenium ion containing a sulfur atom include a trialkyl phosphonium cation such as a trimethyl phosphonium cation, a triethyl phosphonium cation, and a tri(n-butyl) phosphonium cation.

Examples of the ruthenium ion containing an oxygen atom include a trialkyloxonium cation such as a trimethyloxonium cation, a triethyloxonium cation, or a tri(n-butyl)oxonium cation.

Examples of the halide ion include F ^- , Cl ^- , Br ^- , and I ^- .

Examples of the oxyacid anion include a boric acid anion, a carbonate anion, an acetate anion, a sulfate anion, and a phosphate anion.

Examples of the anion containing a boron atom include a tetraalkylborate such as BF ₄ ^- tetramethylborate or tetraethylborate; and a tetraarylborate such as tetraphenylborate or pentium (pentafluorophenyl)borate. Wait.

Examples of the anion containing a phosphorus atom include PF ₆ ^- and the like.

Examples of the quinone imine anion include a bis(perfluoroalkanesulfonyl) quinone imine such as a bis(trifluoromethanesulfonyl) quinone imine anion.

Specific examples of the ionic material include tetrakis(n-butyl)ammonium hexafluorophosphate, 1-(n-butyl)-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) quinone imine, and 1- a tetraalkylammonium salt such as (n-propyl)-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) sulfinimide; an imidazoline such as N,N't-butylmethylimidazolinium hexafluorophosphate a sulfonium salt; a tetraalkylphosphonium salt such as tetrakis(n-butyl)phosphonium bis(trifluoromethanesulfonyl) sulfinium imine or tri(n-butyl)methyl bis(trifluoromethanesulfonyl) ruthenium a trialkylsulfonium salt such as triethylsulfonium bis(trifluoromethanesulfonyl) sulfinimide; a trialkylsulfonium salt such as trimethyloxonium tetrafluoroborate; and the like.

In view of further enhancing the characteristics of the obtained electroluminescent element, it is preferable to use an organic salt having a cerium ion containing a nitrogen atom, a phosphorus atom, a sulfur atom or an oxygen atom, and a cerium ion having a nitrogen atom. The organic salt is preferred, especially tetra(n-butyl)ammonium hexafluorophosphate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) quinone imine, 1-propyl 1-methylpyrrolidinium bis(trifluoromethanesulfonyl) quinone imine or the like is suitable.

In the present invention, the amount of the ionic material to be added is not particularly limited, and is preferably from 0.01 to 50% by mass, preferably from 0.1 to 1.0% by mass in the light-emitting layer, and that the effect can be sufficiently exhibited even when added in such a small amount. .

The method of mixing the luminescent material or the carrier transporting material with the ionic material may be any one, and in the case of using the solid component, a method of mixing the solid component in the liquid component is suitable.

In the organic electroluminescence device of the present invention, the liquid luminescent layer is characterized in that the constituent members of the other elements are not particularly limited, and conventionally known materials can be suitably used.

For example, a transparent electrode typified by indium tin oxide (ITO), indium zinc oxide (IZO), or a polythiophene derivative having a high charge transport property, a polyaniline derivative, or the like can be used as the anode material.

The cathode material may be aluminum, magnesium-silver alloy, aluminum-lithium alloy, lithium, sodium, potassium, rubidium, cesium or the like.

Further, the organic electroluminescence device of the present invention preferably has a structure of a functional separation type film, and is provided with at least three functional layers containing a light-emitting layer between the anode and the cathode.

Examples of such a functional layer include a positive hole transport layer, a positive hole injection layer, an electron transport layer, an electron injection layer, a carrier blocking layer (hole blocking layer, an electron blocking layer), and the like.

The positive hole transport layer is disposed between the anode and the light-emitting layer, and is a layer having a function of transporting the positive hole injected from the anode to the light-emitting layer, and the material thereof is a positive hole transport exemplified by the above-described carrier transport material. The same material as the material.

Further, the positive hole injection layer is provided between the positive hole transport layer and the anode, and is a layer having a function of improving the efficiency of injecting the positive hole from the anode.

Examples of the material for forming the positive hole injection layer include copper phthalocyanine, 4,4', 4", - gin[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA).

The electron transport layer is provided between the cathode and the light-emitting layer, and is a layer having a function of transporting electrons injected from the cathode to the light-emitting layer. The material may be the same as the electron transport material exemplified for the carrier transport material.

The electron injecting layer is disposed between the electron transporting layer and the cathode, and is a layer having a function of improving the injection efficiency of electrons from the cathode.

Examples of the material for forming such an electron injecting layer include lithium oxide (Li ₂ O), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), and fluorination. SrF ₂ , Li (acac), lithium acetate, lithium benzoate, and the like.

The carrier blocking layer is a layer for controlling the light-emitting region, and may be formed between any of the above layers, and has an electron blocking layer formed between the anode and the light-emitting layer and a hole blocking layer formed between the cathode and the light-emitting layer. In the present invention, it is preferred to provide a hole blocking layer. By setting this configuration, the external quantum efficiency and luminance of the organic electroluminescent element can be further improved.

The material that can be used for the hole blocking layer is not particularly limited as long as it can prevent the positive hole from being moved by the liquid light emitting layer, and is further selected from the group consisting of an electron transporting material that is insoluble in the liquid light emitting layer. One or two or more kinds of metal oxides, metal nitrides, metal sulfides, metal oxynitrides, and polymer compounds used in the hole blocking layer are preferred.

The metal oxide, the metal nitride, the metal sulfide, and the metal oxynitride may, for example, contain at least one selected from the group consisting of Ti, Zr, Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, and Mg. The oxides, nitrides, sulfides and oxynitrides of the metal elements of Si, Ta and Sb are preferably titanium oxide, zirconium oxide, zinc sulfide, cadmium sulfide or the like.

Examples of the polymer compound include an aniline copolymer, oligothiophene or polythiophene, a polythiophene derivative, a polyphenyl derivative, a polystyrene derivative, and a polyfluorene derivative.

The film formation of the hole barrier layer may be a dry method such as a vacuum evaporation method, a sputtering method, or the like, an inkjet method, a casting method, a dip coating method, a bar coating method, a knife coating method, or a roll method. The wet method such as a coating method, a gravure coating method, an offset printing method, or a spray coating method is carried out.

The film thickness of the hole blocking layer is preferably from about 1 to 1000 nm, preferably from about 5 to 50 nm, from the viewpoint of ensuring sufficient hole blocking ability and preventing the driving voltage from rising.

Further, the organic electroluminescent device of the present invention can be driven by either of a direct current voltage and an alternating current voltage.

Next, one embodiment of the electroluminescent device of the present invention will be described with reference to the drawings.

Fig. 1 shows an organic EL element 1 of an electroluminescent element to which one embodiment of the present invention is associated.

The organic EL element 1 includes an anode 10, a positive hole injection layer 30 laminated on the anode 10, a cathode 20, a hole blocking layer 40 laminated on the cathode 20, and a positive hole injection layer. Between 30 and the hole blocking layer 40, a light-emitting layer 50 (hereinafter referred to as a liquid light-emitting layer 50) which is liquid at a normal temperature and contains an ionic material.

In the present embodiment, the anode 10 is composed of a glass substrate 11 and an ITO substrate 12 formed thereon.

On the other hand, the cathode 20 is composed of a glass substrate 13 and an ITO substrate 14 formed thereon.

Further, the hole blocking layer 40 is made of titanium oxide, and the positive hole injection layer 30 is made of a PEDOT:PSS film.

The liquid light-emitting layer 50 is composed of a carrier transport material, a light-emitting material, and an ionic material. In the present embodiment, 9-(2-ethylhexyl)carbazole (EHCz) containing a liquid carrier transport material; Red fluorene which is a solid luminescent material; and tetrabutylammonium hexafluorophosphate (TBAPF ₆ ) which is an ionic material which is solid at normal temperature.

The method for producing the organic EL element configured as described above is not particularly limited, and a method such as the following can be used.

First, PEDOT:PSS is applied onto the anode 10 by a spin coating method, and is heated to form a positive hole injection layer 30.

On the other hand, titanium oxide is laminated on the laminate of the glass substrate 13 and the ITO substrate 14 by sputtering to form the hole barrier layer 40.

Next, red fluorene and a solution of 9-(2-ethylhexyl)carbazole (EHCz) containing a predetermined amount of TBAPF ₆ are dropped on the anode 10 (positive hole injection layer 30) to form a liquid luminescent layer 50, The cathode 20 on which the hole blocking layer 40 is laminated is pressed at an appropriate pressure to obtain the organic EL element 1.

Further, the materials constituting each layer are not limited to the materials used in the above embodiments, and any of the materials exemplified above can be appropriately selected and used as long as the functions of the respective layers can be exhibited.

Further, the film formation method of each layer is not limited to the method of the above embodiment, and a known method such as a vapor deposition method, a spray method, an inkjet method, or a sputtering method can be suitably employed depending on the material to be used.

Further, the hole blocking layer or the positive hole injection layer may be formed as necessary, and may have a configuration similar to that of the organic EL element 2 having no hole blocking layer as shown in FIG. 2, for example.

[Examples]

The present invention will be more specifically illustrated by the following examples and comparative examples, but the present invention is not limited by the following examples.

Further, the measuring device used in the examples is as follows.

(1) Current-voltage-luminance characteristics

The measurement was performed by a semiconductor parameter analyzer (B1500A, manufactured by Agilent Co., Ltd.) equipped with a photo sensor and an optical power meter (Newport, 1930C).

(2) EL luminescence spectrum

The measurement was performed by a multi-channel spectroscope (PMA-11, manufactured by Hamamatsu Photonics Co., Ltd.).

(3) ¹ H-NMR

Device: AVANCE500, made by Bruker

Device: JNM-LA400, manufactured by JEOL DATUM Co., Ltd.

(4) Matrix-assisted laser desorption ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS), Autoflex-III. Bruker Daltonics

(5) Atomic Force Microscopy (AFM)

Device: Scanning probe microscope (JSPM-5400, manufactured by JEOL)

(6) Voltage-luminance characteristics when an alternating voltage is applied

A signal generated by an AC power source (SWEEP FUNCTION GENERATOR AD-8623, manufactured by A&D Co., Ltd.) was amplified by a voltage amplifier (HIGH SPEED BIPOLAR AMPLIFIER 4101, manufactured by NF-Corporation Co., Ltd.), and applied to an EL element to be driven. The luminance was measured by an optical power meter (Newport, 1930C), and the voltage was measured with an oscilloscope (MSO 6104A, manufactured by Agilent Co., Ltd.).

[Synthesis Example 1] Synthesis of EHPy

[化15]

4-(1-indolyl)butyric acid (5.8 g, 20.0 mmol), 1-bromo-2-ethylhexane (7.7 g, 40.0 mmol) and potassium carbonate (8.3 g, 60.0 mmol) were added to DMF (7.1 mL) ) and stirred at 90 ° C for 4 hours. After the solvent was distilled off under reduced pressure, chloroform (50 mL) was added and washed with water (50mL×3). Magnesium sulfate was added and dried, and purified by column chromatography (hexane/chloroform = 8/2 (v/v)) to give EHPy (7.41 g) as a colorless transparent liquid. The identification was carried out by ¹ H-NMR spectroscopy. The NMR spectrum is shown in Fig. 34.

[Synthesis Example 2] Synthesis of Ir(ehppy) ₃ (Guest Compound 1)

[Chemistry 16]

2-iodopyridine (3.1 g, 15.0 mmol), 3-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenol (5.0 g, 23.0 mmol) , [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) chloride (1.8 g, 2.00 mmol) and potassium carbonate (9.3 g, 68.0 mmol) suspended in DMF (110 mL) / A mixed solvent of water (60 mL) was stirred at 90 ° C for 3 hours. Then, the insoluble matter was removed from the reaction solution by filtration under reduced pressure, and the solvent was evaporated under reduced pressure. Chloroform (100 mL) was added to the residue, and washed with water (100 mL × 3). After drying over magnesium sulfate, the compound 2 (2.1 g, yield 82%) was obtained by column chromatography (e.c. gel, chloroform/methanol = 99/1 (v/v)).

[化17]

The obtained compound 2 (860 mg, 5.00 mmol), 1-bromo-2-ethylhexane (1.1 g, 6.00 mmol) and potassium carbonate (3.5 g, 25.0 mmol) were added to DMF (17 mL) at 90 ° C Stir under heating for 3 hours. After the reaction solution was allowed to cool, the solvent was distilled off under reduced pressure. Purification by column chromatography (cerium oxide gel, chloroform) gave colorless transparent liquid compound 3 (1.4 g, yield 71%).

[化18]

The above obtained compound 3 (850 mg, 3.00 mmol) and ginseng (2,4-pentanedionate) ruthenium (III) (240 mmg, 0.50 mmol) were added to ethylene glycol (5.0 mL) under a nitrogen stream, and The mixture was stirred under heating at 190 ° C for 80 hours. Chloroform (100 mL) was added to the reaction solution, and the mixture was washed twice with 1N hydrochloric acid, and then washed twice with water. After the organic phase was dried over magnesium sulfate, the solvent was evaporated under reduced pressure. Purification by column chromatography (cerium oxide gel, chloroform/n-hexane = 1:9 to 3:7 (v/v)), and solid-liquid washing with methanol to obtain a brown solid of Ir(ehppy) ₃ (40 mg, yield 7.8%). The identification was carried out by ¹ H-NMR spectroscopy and MALDI-TOF-MS spectroscopy. The NMR spectrum is shown in Fig. 35, and the MALDI-TOF-MS spectrum is shown in Fig. 36.

[Synthesis Example 3] Synthesis of guest compound 2

The guest compound 2 was synthesized according to the following schemes 1 and 2. The ¹ H-NMR spectrum of the guest compound 2 is shown in Fig. 37 .

[Chemistry 19]

Path map 1

[Chemistry 20]

Path map 2

[1] Enhancement of component characteristics obtained by adding salt in the host-guest system [Example 1]

216.7 parts by mass of the guest compound obtained in Synthesis Example 3 and 0.1 parts by mass of tetrabutylammonium hexafluorophosphate (hereinafter referred to as TBAPF ₆ ) of an ionic material were added to the host compound 9-(2- at room temperature in a liquid state. 83.2 parts by mass of ethylhexyl)carbazole (hereinafter referred to as EHCz) was used to completely dissolve the guest compound 2 and TBAPF ₆ in EHCz to prepare a liquid luminescent material.

The EL element was fabricated as follows.

Two ITO glass substrates were prepared, ultrasonically washed in the order of surfactant, pure water, and isopropyl alcohol, and subjected to UV/ozone treatment (UV253S, manufactured by Filgen) for 12 minutes.

PEDOT:PSS (manufactured by Bayer Corporation, PI4083) was spin-coated at 3000 rpm for 30 seconds on a glass substrate 11 with ITO 12, and then heated at 200 ° C for 10 minutes in the atmosphere to obtain a hole injection layer. 30 was formed on the anode side substrate 10 on the ITO 12.

Next, the cathode side substrate 20 composed of another glass substrate 13 with the ITO 14 is placed in a handle box, and a small amount of the previously prepared liquid luminescent material is dropped on the side on which the ITO 14 is formed, and The ITO anode side substrate 10 on which the PEDOT:PSS film was formed was sandwiched, and then fixed by a clip (not shown), and as shown in Fig. 2, a glass substrate / ITO (anode) / PEDOT: PSS 40 nm was produced. / EL element 2 composed of a liquid light-emitting layer / ITO (cathode) / glass substrate. The component area is 2 mm x 2 mm.

The current density-voltage-luminance and luminescence spectrum were measured for the produced EL element. The results are shown in FIGS. 3 and 4. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1100 nm.

As shown in FIG. 3 and FIG. 4, luminescence was observed from 18.0 V, and a current density of 0.99 mA/cm ² , a maximum luminance of 2.3 cd/m ² , and an external EL of 0.051% were obtained at 62.0 V. effectiveness. Further, green electroluminescence having an emission peak at 531 nm was also obtained.

[Comparative Example 1]

An EL element was produced in the same manner as in Example 1 except that TBAPF ₆ was not added to the liquid luminescent material, and the same evaluation was carried out. The results are shown in Figures 3 and 4.

From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1100 nm. As shown in FIGS. 3 and 4, luminescence was observed from 34.1 V, and a current density of 0.95 mA/cm ² , a maximum luminance of 0.015 cd/m ² , and an external quantum efficiency of EL of 0.00034% were obtained at 79 V applied, and In the same manner as in Example 1, green light emission having an emission peak at 531 nm was obtained.

[Embodiment 2]

1.0 parts by mass of 5,6,11,12-tetraphenyl fused tetraphenyl (hereinafter referred to as erythroprene) as a guest compound and 0.1 part by mass of TBAPF ₆ were added to 98.9 parts by mass of EHCz to make erythritol and TBAPF. _{6 is} completely dissolved in EHCz to produce a liquid luminescent material.

An EL element was produced in the same manner as in Example 1 except that the above liquid luminescent material was used, and the same evaluation was performed. The results are shown in FIGS. 5 and 6. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 380 nm.

As shown in Fig. 5 and Fig. 6, luminescence was observed from 6.6 V, and a current density of 0.11 mA/cm ² , a maximum luminance of 0.034 cd/m ² , and an external quantum efficiency of EL of 0.014% were obtained at 15.0 V application. And an orange luminescence having an emission peak of 557 nm is obtained.

[Comparative Example 2]

An EL element was fabricated in the same manner as in Example 2 except that TBAPF ₆ was not added to the liquid luminescent material, and evaluated in the same manner. The results are shown in Figures 5 and 6. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 530 nm.

As shown in Fig. 5 and Fig. 6, luminescence was observed from 40.1 V, and a current density of 0.21 mA/cm ² , a maximum luminance of 0.023 cd/m ² , and an external quantum efficiency of EL of 0.0048% were obtained when 93.2 V was applied. In the same manner as in Example 2, orange light emission having an emission peak of 557 nm was obtained.

As described above, when the examples 1 and 2 were compared with the comparative examples 1 and 2, it was found that the fluorescent dye was dissolved in the liquid main body, and when the organic salt was further added, the driving voltage was lowered, and the luminance and the EL were improved. External quantum efficiency.

[2] In the system that does not use the subject-guest system, the component characteristics obtained by adding salt are improved. [Example 3]

An EL element was produced in the same manner as in Example 1 except that the guest compound 1 was not added to the liquid luminescent material, and the same evaluation was carried out. The results are shown in FIGS. 7 and 8. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 800 nm.

As shown in FIGS. 7 and 8, in the case of this element, light emission was observed from 15.8 V, and a current density of 1.5 mA/cm ² and a maximum luminance of 0.13 cd/m ² were obtained when 80.6 V was applied. A current density of 0.96 mA/cm ² and an external quantum efficiency of EL of 0.017% were obtained at 71.4 V, and blue light emission having an emission peak at 476 nm was obtained.

[Comparative Example 3]

An EL element was produced in the same manner as in Example 3 except that TBAPF ₆ was not added to the liquid luminescent material, and the same evaluation was performed. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 900 nm. As shown in Fig. 7, in the case of this element, a current density of 0.11 mA/cm ² was obtained upon application of 100 V, however, no luminescence was observed.

[Example 4]

An EL element was produced in the same manner as in Example 1 except that the liquid luminescent material composed of 99.9 parts by mass of the liquid host compound EHPy and 0.1 part by mass of TBAPF ₆ obtained in Synthesis Example 1 was used, and the same operation was carried out. Evaluation. The results are shown in FIGS. 9 and 10. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1150 nm.

As shown in Fig. 9 and Fig. 10, luminescence was observed from 18.4 V, and a current density of 146 mA/cm ² and a maximum luminance of 416 cd/m ² were obtained at 64.4 V, and 2.9 mA was obtained at 46.8 V. The current density of /cm ² and the maximum EL external quantum efficiency of 0.13%, and a blue-green electroluminescence having a peak at 486 nm can be obtained.

[Comparative Example 4]

An EL element was fabricated in the same manner as in Example 4 except that TBAPF _{6 was} not added, and the same evaluation was performed. The results are shown in FIGS. 9 and 10. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 690 nm.

As shown in Fig. 9 and Fig. 10, electroluminescence was observed from 60.8 V, and a current density of 0.067 mA/cm ² and a maximum luminance of 0.58 cd/m ² and an external EL quantum of 0.23% were obtained at 100 V application. In the same manner as in Example 4, blue-green electroluminescence having an emission peak at 486 nm was obtained in the same manner as in Example 4.

When the above-mentioned Examples 3 and 4 are compared with Comparative Examples 3 and 4, it is understood that an organic element having a light-emitting layer formed by using a liquid compound having both charge transportability and luminescence as a liquid luminescent material is organic The addition of salt to the liquid luminescent material also reduces the driving voltage while increasing the luminance and the external quantum efficiency of the EL.

[3] Electroluminescence in a system using phosphorescent luminescent objects [Example 5]

Except that 2.7 parts by mass of EHCz obtained as the host compound obtained in Synthesis Example 1 and 7.2 parts by mass of Ir(ehppy) ₃ (guest compound 1) obtained in Synthesis Example 2 and as a guest compound, and 0.1 part by mass of TBAPF ₆ An EL element was produced in the same manner as in Example 1 except for the liquid luminescent material, and the same evaluation was performed. The results are shown in Fig. 11 and Fig. 12. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1230 nm.

As shown in Fig. 11 and Fig. 12, luminescence was observed from 44.8 V, and a current density of 1.3 mA/cm ² , a maximum luminance of 2.9 cd/m ² , and a maximum EL external quantum of 0.052% were obtained when 93.6 V was applied. Efficiency, and orange electroluminescence with an emission peak at 559 nm is obtained.

[Comparative Example 5]

An EL element was fabricated in the same manner as in Example 5 except that TBAPF _{6 was} not added, and the same evaluation was performed. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 930 nm. As shown in Fig. 11, a current density of 0.19 mA/cm ² was obtained from this element when 100 V was applied, and no light emission was observed.

When the above-described Example 5 is compared with Comparative Example 5, it is understood that when the organic light salt is added to the liquid light-emitting material in which the phosphorescent dye is dissolved in the liquid main body, the driving voltage is lowered, and as a result, the luminance is lowered. Or the external quantum efficiency of the EL is improved, and good luminescence characteristics can be obtained.

[4] Systems using other guest compounds or host compounds [Embodiment 6]

The guest compound 3 (manufactured by American Dye Source Co., Ltd.), 10.0 parts by mass and TBAPF ₆ 0.1 mass, which is represented by the following formula and which is C9.9-TEG as a host compound, and which is represented by the following formula, is represented by the following formula. An EL element was produced in the same manner as in Example 1 except for the liquid luminescent material composed of the parts, and the same evaluation was performed. The results are shown in FIGS. 13 and 14. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1090 nm.

As shown in Fig. 13 and Fig. 14, luminescence was observed from 16.0 V, and a current density of 0.52 mA/cm ² , a maximum luminance of 0.25 cd/m ² , and an external quantum efficiency of EL of 0.074% were obtained at 40.0 V application. And a blue luminescence having an emission peak at 419 nm was obtained.

Further, Cz-TEG was synthesized by the method described in Synthetic Metals, 89 (3), 171 (1997).

[Chem. 21]

[化22]

[Embodiment 7]

A liquid luminescent material composed of 69.9 parts by mass of a guest compound 4 (manufactured by American Dye Source Co., Ltd.) and a 0.1 mass part of TBAPF ₆ as a guest compound represented by the following formula and using 69.9 parts by mass of Cz-TEG is used. An EL element was fabricated in the same manner as in Example 1 and subjected to the same evaluation. The results are shown in Figs. 15 and 16 . From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1090 nm. As shown in Fig. 15 and Fig. 16, luminescence was observed from 15.8 V, and a current density of 0.17 mA/cm ² , a maximum luminance of 0.83 cd/m ² , and an external quantum efficiency of EL of 0.24% were obtained at 40.0 V application. And a blue luminescence having an emission peak of 470 nm was obtained.

[化23]

[Embodiment 8]

A liquid luminescent material composed of 20.0 parts by mass of a guest compound 5 (manufactured by American Dye Source Co., Ltd.) and a 0.1 mass part of TBAPF ₆ as a guest compound represented by the following formula and having a Cz-TEG content of 79.9 parts by mass is used. An EL element was produced in the same manner as in Example 1 and subjected to the same evaluation. The results are shown in Fig. 17 and Fig. 18. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 390 nm.

As shown in Fig. 17 and Fig. 18, luminescence was observed from 3.6 V, and a current density of 1.35 mA/cm ² , a maximum luminance of 7.0 cd/m ² , and an external quantum efficiency of EL of 0.23% were obtained at 20.0 V application. And a green luminescence having an emission peak of 514 nm was obtained.

[Chem. 24]

As shown in Examples 6 to 8, it is understood that when a host compound different from EHCz or a various guest compound is used, a low driving voltage and an EL external quantum efficiency exceeding 0.1% can be obtained from an element to which an organic salt is added. .

[5] Improvement of external quantum efficiency of luminescence generated by the hole barrier layer [Embodiment 9]

Two ITO glass substrates were prepared, ultrasonically washed in the order of surfactant, pure water, and isopropyl alcohol, and subjected to UV/ozone treatment (UV253S, manufactured by Filgen) for about 12 minutes.

PEDOT:PSS (manufactured by Bayer Co., Ltd., PI4083) was spin-coated at 3000 rpm for 30 seconds on a glass substrate 11 with ITO 12, and then heated at 200 ° C for 10 minutes in the atmosphere to obtain cavity injection. The layer 30 is formed on the anode side substrate 10 on the ITO 12.

Next, on the ITO 14 side of the glass substrate 13 with the ITO 14 attached thereto, TiO _{2 was} formed into a film by a sputtering method at a film thickness of 10 nm to form a hole blocking layer 40, whereby the cathode side substrate 20 was obtained. A small amount of the same liquid luminescent material as in Example 1 was dropped on the hole blocking layer 40, and was sandwiched by an anode side substrate 10 on which a PEDOT:PSS film was formed, and then fixed by a clip (not shown). An EL element 1 composed of a glass substrate / ITO (anode) / PEDOT: PSS 40 nm / liquid light-emitting layer / TiO ₂ (hole blocking layer) 10 nm / ITO (cathode) / glass substrate was produced as shown in FIG. The component area is 2 mm x 2 mm. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1100 nm. The current density, luminance, voltage, external quantum efficiency of EL, and luminescence spectrum were evaluated in the same manner as in Example 1. The results are shown in FIGS. 19 and 20.

As shown in Fig. 19 and Fig. 20, luminescence was observed from 15.0 V, and a current density of 3.72 mA/cm ² , a maximum luminance of 76.8 cd/m ^{2 , and} a maximum external EL efficiency of 0.37% were obtained at 100 V application. In the same manner as in Example 1, green electroluminescence having an emission peak of 531 nm was obtained.

[Embodiment 10]

An EL element was produced in the same manner as in Example 9 except that a liquid luminescent material composed of 98.9 parts by mass of EHCz, 1.0 part by mass of a red fluorene as a guest compound, and 0.1 part by mass of TBAPF ₆ was used. evaluation of. The results are shown in Fig. 21 and Fig. 22. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1210 nm.

As shown in Fig. 21 and Fig. 22, luminescence was observed from 15.6 V, and a current density of 0.64 mA/cm ² , a maximum luminance of 5.0 cd/m ² , and a maximum EL external quantum of 0.16% were obtained at 47.2 V. In the same manner as in Example 2, orange electroluminescence having a peak at 558 nm was obtained.

[Example 11]

An EL element was produced in the same manner as in Example 9 except that a liquid luminescent material composed of 99.9 parts by mass of EHCz and 0.1 part by mass of TBAPF _{6 was} used, and the same evaluation was carried out. The results are shown in FIGS. 23 and 24. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 620 nm.

As shown in Fig. 23 and Fig. 24, luminescence was observed from 9.6 V, and a current density of 8.5 mA/cm ² , a maximum luminance of 5.7 cd/m ² , and a maximum EL external quantum of 0.10% were obtained when 66.6 V was applied. With the same efficiency as in Example 3, blue electroluminescence having an emission peak at 474 nm was obtained.

When Example 9 is compared with Example 1, Example 10, and Example 2, and Example 11 and Example 3, respectively, an organic EL element having a light-emitting layer composed of a liquid luminescent material to which an organic salt is added is known. Among them, by introducing a hole blocking layer (TiO ₂ layer) between the cathode and the light-emitting layer, the external quantum efficiency is improved, and the luminance is also increased.

[6] Enhancement of component characteristics obtained by ionic liquid addition [Embodiment 12]

In addition to using 99.9 parts by mass of EHCz as an ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) quinone imine (hereinafter referred to as BMPyTFSI) 0.1 parts by mass An EL element was produced in the same manner as in Example 9 except for the liquid luminescent material, and the same evaluation was performed. The results are shown in FIGS. 25 and 26. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 960 nm.

As shown in Fig. 25 and Fig. 26, luminescence was observed from 27.6 V, and a current density of 6.67 mA/cm ² , a maximum luminance of 0.23 cd/m ² , and a maximum EL external quantum of 0.013% were obtained when 96.8 V was applied. Efficiency, blue electroluminescence with a peak at 453 nm is obtained.

[Example 13]

An EL element was produced in the same manner as in Example 9 except that a liquid luminescent material composed of 98.9 parts by mass of EHCz, 1.0 part by mass of erythritol, and 0.1 part by mass of BMPyTFSI was used, and the same evaluation was carried out. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 960 nm.

As shown in Fig. 27 and Fig. 28, luminescence was observed from 7.6 V, and a current density of 1.56 mA/cm ² , a maximum luminance of 32.5 cd/m ² , and a maximum EL external quantum of 0.44% were obtained at 45.2 V application. Efficiency, and orange electroluminescence with a peak at 557 nm is obtained.

Comparing Example 9 with Example 12 and Example 10 and Example 13, it can be seen that even when an ionic liquid is added, the same driving voltage can be reduced, and the same luminance can be obtained. The external quantum efficiency of the EL is improved.

[7] Concentration dependence of ionic liquids [Embodiment 14]

An EL element was produced in the same manner as in Example 12 except that a liquid luminescent material composed of 9 parts by mass of EHCz and 1.0 part by mass of BMPyTFSI was used, and the same evaluation was carried out. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1030 nm.

In addition, luminescence was observed from 19.0 V, and a current density of 3.50 mA/cm ² , a maximum luminance of 1.7 cd/m ² , a maximum EL external quantum efficiency of 0.20%, and a peak at 451 nm were obtained at 67.6 V. Blue electroluminescence.

[Example 15]

An EL element was produced in the same manner as in Example 12 except that a liquid luminescent material composed of 90.0 parts by mass of EHCz and 10.0 parts by mass of BMPyTFSI was used, and the same evaluation was carried out. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1050 nm.

In addition, luminescence was observed from 11.2 V, and a current density of 3.54 mA/cm ² , a maximum luminance of 0.20 cd/m ² , a maximum EL external quantum efficiency of 0.035%, and a peak at 443 nm were obtained at 44.4 V. Blue electroluminescence.

The results of comparing the luminance voltage characteristics of the elements of Example 12, Example 14, and Example 15 are shown in Fig. 29. As shown in Fig. 29, it is understood that a lower driving voltage can be achieved by increasing the amount of the ionic compound added between the elements having the liquid illuminant layer having the same film thickness.

[8] Comparison of the use of different ionic liquids [Example 16]

Using the liquid luminescent material of Example 14, an EL element was produced in the same manner as in Example 14, and the same evaluation was carried out. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 880 nm.

[Example 17]

An EL element was produced in the same manner as in Example 16 except that 1-isopropyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) ruthenium was used as the ionic liquid, and the same was carried out. Evaluation. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 840 nm.

[Embodiment 18]

An EL element was produced in the same manner as in Example 16 except that tributylmethyl bis(trifluoromethanesulfonyl) ruthenium was used as the ionic liquid, and the same evaluation was carried out. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 750 nm.

The luminance voltage characteristics of the elements produced in the above Examples 16 to 18 are shown in Fig. 30. From the results of Fig. 30, it is known that low voltage driving is generally achieved by adding an ionic liquid.

[9] Evaluation of film thickness dependence of hole barrier layer [Embodiment 19]

In Example 9, an EL element was produced by changing the film thickness of TiO ₂ from 0 nm to 20 nm, and evaluated in the same manner as in Example 9.

[Example 20]

In Example 10, an EL element was produced by changing the film thickness of TiO ₂ from 0 nm to 20 nm, and evaluation was performed in the same manner as in Example 10.

The relationship between the EL external quantum yield of the EL element obtained in the above-described Example 19 and Example 20 and the film thickness of the TiO ₂ layer is shown in Fig. 31 . As shown in FIG. 31, it was found that in both of Example 19 and Example 20, as the film thickness of the TiO ₂ layer was increased, the external quantum efficiency of EL was increased, and the film thickness of 10 nm or more was saturated.

Further, the TiO ₂ layer on the ITO cathode of the EL element produced in Example 19 and Example 20 was observed by an atomic force microscope (AFM). The obtained AFM image is shown in Fig. 32.

FIG. (I) and (ii) 32 as shown, the height difference of the cathode itself ITO film is about 2nm, By contrast, in the case where the TiO ₂ layer having a film thickness of 10nm or less, the level of the TiO ₂ layer The difference was about 8 nm, and it was found that the TiO ₂ layer was not completely coated on the ITO cathode, and it became a dot-like film. Therefore, when the TiO ₂ layer is 8 nm or less, the blocking effect of the hole is insufficient.

On the other hand, as shown in Fig. 32 (iii), even if the film thickness is 10 nm or more, the height difference of the TiO ₂ film does not increase and is maintained at a constant value of about 8 nm. From this, it is understood that in the case of a film thickness of 10 nm or more, at least the ITO cathode is completely covered with the TiO ₂ layer. Therefore, it is understood that when the film thickness of the TiO ₂ layer is 10 nm or more, since a good hole blocking function is achieved, the recombination probability of the carrier is improved, and the external quantum yield of electroluminescence is improved.

[10] Making liquid flow while producing electroluminescence [Example 21]

As shown in Fig. 33 (i), a liquid luminescent material composed of 99.99 parts by mass of EHPy and 0.1 part by mass of TBAPF _{6 was} dropped on the side of an ITO tank (manufactured by EHC Co., Ltd.) having a gap of 10 μm. The liquid luminescent material is caused to emit light by UV light, and the liquid luminescent material is moved between the ITO baths having a gap of 10 μm by capillary action. As a result, the liquid luminescent material is as shown in Fig. 33(ii). As shown in (v), it moves from the upper side to the lower side at a speed of about 0.2 mm/min.

Five minutes after the dropwise addition, the liquid luminescent material was in the state of Fig. 33 (ii). At this time, a voltage of 170 V was applied between the two ITO electrodes, and no light was observed as shown in Fig. 33 (vi).

Ten minutes after the dropwise addition, the liquid luminescent material became in the state of Fig. 33 (iii). At this time, a voltage of 170 V was applied between the two ITO electrodes, as shown in Fig. 33 (vii), only observed at the intersection of the ITO electrodes. To the blue-green glow from EHPy.

15 minutes after the dropwise addition, the liquid luminescent material became in the state of Fig. 33 (iv). At this time, a voltage of 170 V was applied between the two ITO electrodes, as shown in Fig. 33 (viii), at the intersection of the ITO electrodes. Blue-green luminescence from EHPy was observed.

After 30 minutes from the dropping, the liquid luminescent material became in the state of Fig. 33 (v). At this time, a voltage of 170 V was applied between the two ITO electrodes, as shown in Fig. 33 (ix), at the intersection of the ITO electrodes. Blue-green luminescence from EHPy was observed.

As described above, it can be seen that the liquid luminescent material always moves between the electrodes while electroluminescence is also observed.

[Example 22]

A liquid luminescent material composed of 83.1 parts by mass of EHCz, 16.6 parts by mass of the guest compound 2, and 0.3 part by mass of TBAPF _{6 was} injected into an ITO tank (manufactured by EHC Co., Ltd.) having a gap of 10 μm similar to that of Example 21.

As a result of applying a voltage of 170 V between the two ITO electrodes, the state of Fig. 38 (i) was obtained, and the light emission from the guest compound 2 was observed. Fig. 38 (iv) shows the PL illumination situation at this time. The case where the liquid luminescent material deteriorates until the luminescence of the guest compound 2 disappears after 5 minutes after the application of the voltage is shown in Fig. 38 (ii). In the PL light emission of Fig. 38 (v), it was confirmed that the light-emitting intensity due to deterioration was reduced in the portion in contact with the ITO. After the deterioration of the liquid luminescent material, a new liquid luminescent material was injected by capillary phenomenon, and a voltage of 170 V was applied, which is shown in Fig. 38 (iii). It can be seen that the light emission of the element can be restored by replacing the deteriorated luminescent material with a new liquid luminescent material. Further, among the PL light emission of Fig. 38 (vi), it was confirmed that the deteriorated light-emitting material flows and is replaced with a new light-emitting material.

As described above, even if the liquid luminescent material has deteriorated, the component can be restored by injecting a new liquid luminescent material.

[11] Electroluminescence when AC voltage is applied [Example 23]

In addition to the use of a liquid luminescent material composed of EHPy 99.75 parts by mass and 0.25 parts by mass of tributyl(2-methoxyethyl)indole bis(trifluoromethanesulfonyl) ruthenium, 1 EL element was produced in the same manner. From the results of the dielectric constant measurement, the film thickness of the liquid light-emitting layer of this device was calculated to be 1.20 ± 0.06 μm. A direct current and an alternating current voltage were applied to the produced EL element, and the luminance-voltage characteristics at this time were measured. The results are shown in Fig. 39.

As shown in Fig. 39, when a direct current voltage is applied, light emission is observed from 2.5 V, and a maximum luminance of 37.4 cd/m ² is obtained when 10.5 V is applied, whereas 2.2 is applied when an alternating current voltage of 1 Hz is applied. Light emission was observed at V, and a maximum luminance of 115 cd/m ² was obtained when 12.0 V was applied. Further, when an alternating voltage of 10 Hz was applied, light emission was observed from 10.0 V, and when 38.0 V was applied, a maximum luminance of 92.3 cd/m ² was obtained. Further, luminescence was observed from 15.0 V when an AC voltage of 100 Hz was applied, and a maximum luminance of 22.8 cd/m ² was obtained at 42.0 V.

As described above, it is understood that light is observed when any of a direct current voltage and an alternating voltage is applied, and electroluminescence can be observed even when an alternating voltage is applied.

1, 2. . . Organic EL element (electroluminescence element)

10. . . anode

20. . . cathode

30. . . Positive hole injection layer

40. . . Hole barrier

50. . . Liquid luminescent layer

Fig. 1 is a schematic cross-sectional view showing an organic EL device according to a first embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing an organic EL device according to a second embodiment of the present invention.

3 is a graph showing current density-voltage-luminance characteristics of the EL elements produced in Example 1 and Comparative Example 1.

4 is a graph showing EL external quantum yield-current density characteristics of EL elements produced in Example 1 and Comparative Example 1. FIG.

Fig. 5 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Example 2 and Comparative Example 2.

Fig. 6 is a graph showing EL external quantum yield-current density characteristics of EL elements produced in Example 2 and Comparative Example 2.

Fig. 7 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Example 3 and Comparative Example 3.

Fig. 8 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 3.

Fig. 9 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Example 4 and Comparative Example 4.

Fig. 10 is a graph showing EL external quantum yield-current density characteristics of EL elements produced in Example 4 and Comparative Example 4.

Fig. 11 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Example 5 and Comparative Example 5.

Fig. 12 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 5.

Fig. 13 is a graph showing the current density-voltage-luminance characteristics of the EL element produced in Example 6.

Fig. 14 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 6.

Fig. 15 is a graph showing the current density-voltage-luminance characteristics of the EL element produced in Example 7.

Fig. 16 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 7.

Fig. 17 is a graph showing current density-voltage-luminance characteristics of the EL element produced in Example 8.

Fig. 18 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 8.

Fig. 19 is a graph showing current density-voltage-luminance characteristics of the EL elements produced in Example 9 and Example 1.

Fig. 20 is a graph showing the EL external quantum yield-current density characteristics of the EL elements produced in Example 9 and Example 1.

Fig. 21 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Examples 10 and 2.

Fig. 22 is a graph showing the EL external quantum yield-current density characteristics of the EL elements produced in Examples 10 and 2.

Fig. 23 is a graph showing current density-voltage-luminance characteristics of EL elements produced in Examples 11 and 3.

Fig. 24 is a graph showing the EL external quantum yield-current density characteristics of the EL elements produced in Example 11 and Example 3.

Fig. 25 is a graph showing current density-voltage-luminance characteristics of the EL element produced in Example 12.

Fig. 26 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 12.

Fig. 27 is a graph showing the current density-voltage-luminance characteristics of the EL element produced in Example 13.

Fig. 28 is a graph showing the EL external quantum yield-current density characteristics of the EL element produced in Example 13.

Fig. 29 is a graph showing the comparison of the luminance-voltage characteristics of the EL elements produced in Examples 12, 14 and 15.

Fig. 30 is a graph showing the comparison of the luminance-voltage characteristics of the EL elements produced in Examples 16 to 18.

31 is a graph showing the relationship between the EL external quantum yield of the EL element produced in Example 19 and Example 20 and the film thickness of the TiO ₂ layer.

32 is an AFM image of the TiO ₂ layer on the ITO cathode in the EL element produced in Example 19 and Example 20, wherein (i) shows a TiO ₂ -free layer and (ii) shows a TiO ₂ layer of 315 nm, (iii) shows a TiO ₂ layer of 10 nm.

Figure 33 is a diagram showing the flow of a liquid luminescent material in an EL element composed of ITO (anode) / 0.1% by mass - (n-Bu) ₄ NPF ₆ , EHPy (10 μm) / ITO (cathode) produced in Example 21. A diagram of the illuminating situation when an electric field is applied at the same time.

Fig. 34 is a ¹ H-NMR spectrum chart of EHPy obtained in Synthesis Example 1.

Fig. 35 is a ¹ H-NMR spectrum chart of Ir(ehppy) ₃ (guest compound 1) obtained in Synthesis Example 2.

Fig. 36 is a MALDI-TOF-MS spectrum chart of Ir(ehppy) ₃ (guest compound 1) obtained in Synthesis Example 2.

Fig. 37 is a ¹ H-NMR spectrum chart of the guest compound 2 obtained in Synthesis Example 3.

38 is a view showing that ITO (anode)/0.3% by mass-(n-Bu) ₄ NPF ₆ , 83.1% by mass-EHCz, and guest compound 2 16.6 mass% (10 μm) / ITO (cathode) were produced in Example 22. The liquid luminescent material in the EL element formed is illuminated to deteriorate, and then the liquid luminescent material is re-injected, and the luminescence recovery of the element is illustrated.

Fig. 39 is a graph showing a comparison of luminance-voltage characteristics when DC and AC voltages are applied to the EL element produced in Example 23.

Claims (9)

An organic electroluminescence device comprising: an anode, a cathode, and a light-emitting layer interposed between the electrodes and at a normal temperature, wherein the light-emitting layer contains a material having a carrier transporting ability and a light-emitting ability, And the ionic material, or the luminescent material containing the ionic material, the carrier transporting material which is liquid at normal temperature, and the luminescent material, the material having the carrier transporting ability and the luminescent ability or the carrier transporting material is the following formula (3) or (Z2): [In the formula (3), Y ³ represents an alkyl group having 1 to 30 carbon atoms including an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond, and each of W ¹ to W ⁴ in the formula (Z2) Independently, it represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms such as an ether bond, a thioether bond, an ester bond, a carbonate bond or a guanamine bond (however, at least one of W ¹ to W ⁴ is the aforementioned alkane base)〕. The organic electroluminescence device according to claim 1, wherein the material having the carrier transporting ability and the light-emitting ability or the carrier transporting material is represented by the following formula (5) or (Z3): The organic electroluminescent device according to claim 1, wherein the ionic material is selected from the group consisting of a liquid organic salt, a liquid inorganic salt, an organic salt dispersible in a liquid carrier transport material or a liquid luminescent material, and One or two or more kinds of inorganic salts which can be dispersed in the liquid carrier transport material or the liquid luminescent material. An organic electroluminescence device according to claim 3, wherein the ionic material contains a compound represented by the formula [1], (A ⁿ⁺ ) _i (B ^m- ) _j [1] [wherein, A ⁿ⁺ is n (n represents an integer of 1 to 10) The cation component of the valence represents a metal ion or a ruthenium ion containing a nitrogen atom, a phosphorus atom, a sulfur atom or an oxygen atom, and B ^m- is m (m represents an integer of 1 to 10). The anion component represents a halide ion, an oxyacid anion, an anion containing a boron atom, an anion containing a phosphorus atom, and an anthraquinone anion, and i and j are each an integer of 1 to 100, and the formula [1] The ionic material represented becomes an electrically neutral integer]. The organic electroluminescence device according to any one of claims 1 to 4, wherein the luminescent material contains 0.01 to 50% by mass of the ionic material. The organic electroluminescence device according to any one of claims 1 to 4, further comprising a functional separation type thin film structure comprising at least three functional layers including the light-emitting layer. An organic electroluminescence device according to claim 6, wherein a hole blocking layer interposed between the cathode and the light-emitting layer is used as the functional layer. The organic electroluminescence device of claim 7, wherein the hole blocking layer contains one or more selected from the group consisting of metal oxides, metal nitrides, metal sulfides, metal oxynitrides, and polymer compounds. . The organic electroluminescence device of claim 8, wherein the hole blocking layer contains one or more selected from the group consisting of an oxide, a nitride, a sulfide, and an oxynitride of a metal element. The metal element is at least one selected from the group consisting of Ti, Zr, Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, and Sb.