WO2008067308A1

WO2008067308A1 - The growth of cadmium sulfide films under aqueous conditions using a biomimetic approach

Info

Publication number: WO2008067308A1
Application number: PCT/US2007/085635
Authority: WO
Inventors: Laurie B. Gower
Original assignee: University Of Florida Research Foundation, Inc.
Priority date: 2006-11-27
Filing date: 2007-11-27
Publication date: 2008-06-05

Abstract

The present invention provides a method for depositing a ceramic film (such as a semiconductor film) on a substrate (template), under aqueous based conditions and the product formed by the method. The method involves templating an amorphous CdS film, or other inorganic film, onto a substrate, such as a self-assembled monolayer (SAM) patterned by soft lithography. The polymeric process-directing agent induces an amorphous phase with fluidic properties that can coalesce into a smooth and continuous film, such that patterning of the amorphous precursor provides a way to regulate the location and morphology of thin films.

Description

DESCRIPTION

THE GROWTH OF CADMIUM SULFIDE FILMS UNDER AQUEOUS CONDITIONS USING A BIOMIMETIC APPROACH

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application Serial No. 60/861,597, filed November 27, 2006, which is hereby incorporated by reference herein in its entirety, including any figures, tables, nucleic acid sequences, amino acid sequences, and drawings.

BACKGROUND OF THE INVENTION

Non-equilibrium morphologies and growth of biominerals, such as calcium carbonates in abalone nacre and hydroxyapatite in bone, have been assumed to be controlled by organic materials (insoluble organic matrix and soluble proteins), and many researchers have been investigating biominerals to verify the relationship between biominerals and organic phases in biological systems.

Many types of inorganic crystals found in biological systems are closely associated with organic materials, such as calcium carbonate tablets formed within the conchiolin membrane of mollusk shell, hydroxyapatite nanocrystals embedded within collagen of bone, and metastable iron oxide encapsulated within ferritin storage protein (D. Allemand & J. -P. Cuif, Biomineralization, 1994, Bulletin de I'Imtitut oceanographique, 93, Monoco; S. Weiner and H. D. Wagner, Annu. Rev, Mater. ScL, 1998, Vol. 28: 271-298). Gower et al. have proposed a mechanism, called the PILP (Polymer-Induced-Liquid-

Precursor) process, which uses process-directing polymer to mimic the function of soluble protein and induce the highly fluidic liquid precursors for biominerals. The general process introduces the anionic poly-amino acids into an aqueous salt solution which is slowly raised in supersaturation. One common method for raising supersaturation is to slowly introduce one of the ionic species, for example using a modified vapor diffusion technique developed by Addadi et al (Addadi, L. et al. Proc. Natl. Acad. Set USA, 1985, 82:4110-4114), in which ammonium carbonate (NH₄^CO₃ vapor, produced by decomposition of its powder, diffuses into a solution containing calcium chloride CaCl₂ and the polymeric additive. This multistage process is illustrated by the formula:

(NH4)2CO3(v)

CaCl₂(aq) +P(D)(aq) * CaCO₃-P(D)-H₂O(I) ^■» CaCO₃(s)

Stage I Stage II Precursor Deposition Precursor Transformation

This PILP process could provide an alternative explanation as to how the unique microstructures in biominerals are formed, and have demonstrated that means of mimicking such processes. Examples of such microstructures, which can be successfully modeled by PILP. include mollusk shell, sea urchin spine, teeth and bone.

The present inventors have examined crystal growth mediated by organic materials, such as various proteins, polypeptides, and self-assembled monolayers. Self-assembled monolayers (SAMs) have been used to control and pattern the properties of a variety of surfaces. Much work has been done over the last decade on SAMs created on substrates such as silicon, silicon dioxide, silver, copper, or gold. Research on thiol monolayers on gold surfaces has resulted in technologies such as soft lithography. Applications of SAMs include sensor development, corrosion protection and heterogeneous catalysis. SAMs have been used as templates for organic synthesis and layer-by-layer adsorption. Their interaction with cells and proteins is well understood and micro-structured SAMs have been used to manipulate cells. All these techniques are based on a common approach: spontaneous monolayer formation of thiols on gold was used to achieve a densely packed two- dimensional crystal which offers reactive head groups for further modification. Chemisorption of thiols on gold occurs as a self-driven process and the packing of the thiols is mainly determined by geometrical aspects. BRIEF SUMMARY OF THE INVENTION

In prior research, it has been shown that the size and shape of calcium carbonate and calcium phosphate crystals can be controlled by process-directing agents, such as anionic poly-amino acids, which generate a highly hydrated amorphous precursor, called the polymer-induced-liquid-precursor (PILP) phase. This process was first discovered for calcium carbonate mineral, in which it was demonstrated that a variety of non-equilibrium crystal morphologies can be generated. The present inventors have investigated the possibility of generating this PILP process with non-biological, but industrially significant inorganic materials, such as cadmium sulfide (CdS). The method of the invention involves templating an amorphous CdS film, or other inorganic film, onto a desired substrate, such as self-assembled monolayers (SAMs) patterned by soft lithography. The polymeric process-directing agent stabilizes the amorphous phase and alters the amorphous to crystalline transformation, such that patterning of the amorphous precursor provides a means for regulating the location and morphology of thin films.

The products of this invention (e.g., a thin film of a semiconductor, or a substrate coated with a thin film of a semiconductor) are useful in the construction of electronic devices, such as photovoltaic cells and thin film transistors.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a micrograph showing the upper surface of abalone nacre.

Figure 2 is a micrograph showing a CaCO₃ film on a self-assembled monolayer (SAM), produced by the PILP process.

Figure 3 is a TEM image of bone. Figure 4 is a micrograph of mineralized bovine tendon produced via the PILP process.

Figure 5 shows a drawing of SAM deposited on gold islands previously coated on a silicon wafer.

Figure 6 shows a drawing of templates placed in solution containing Cd²⁺ ion. Petri- dishes were sealed with stretched parafilm, and 3 holes were introduced. Sulfur ions were introduced via vapor diffusion through the holes. Poly-acrylic acid or poly-aspartic acid was added as a process-directing agent. Blue spheres = Cd²⁺; yellow spheres = S² (released from thioacetamide); and red line = poly-aspartic acid or poly-acrylic acid.

Figures 7A and 7B show optical micrographs of CdS particles produced by mixing of CdCl₂ and Na₂S solution. Figure 7A: without PAA; Figure 7B: with PAA (Mw: 8000).

Figure 8 is a graph showing XRD patterns of CdS particles produced by mixing of CdCl₂ and Na₂S solution. The concentration of Cd²⁺ and S^2" were 5 mM and reaction time was 3 days. Poly-acrylic acid was added into reacting solution and its concentration was lOOμg/ml. Figure 9 is a micrograph showing that, upon CdS formation via the vapor diffusion method, without PAA, CdCO₃ was formed at the air/solution interface. CdCO^ aggregates were on the unidentified film that formed at the air/solution interface (5mM Cd²⁺).

Figure 10 is a graph showing XRD pattern of film without PAA.

Figures HA and HB are micrographs showing that, upon CdS formation via the vapor diffusion method, with PAA added as a process-directing agent, a very thin and continuous film was formed at the air-solution interface (Figure 1 IA), and the edges of the films showed birefringence (Figure HB). Film formation was observed for every solution containing

PAA, from concentrations of 2, 5, 10 and 20 μg/ml, and continuous film was formed from solutions containing 5 μg/ml of PAA and higher. Figure 1 IA: 5mM Cd²⁺, 20 μg/ml of PAA; Figure 1 IB: without gypsum plate.

Figure 12 is a graph showing the XRD pattern of a film, which shows a very broad peak of CdS around 26.5 degrees, which was occasionally observed from CdS synthesized from chemical bath.

Figures 13A-13D show results of CdS formation on SAM (3 days of reaction). Because of the small thickness of the CdS film deposited on the SAM, an accelerating voltage of SEM was reduced to 4kV in order to see an image of the pattern. Figure 13D shows an SEM image of CdS patterns taken by the BSE mode. Figure 13A: 5mM Cd²⁺, 20 μg/ml of PAA; Figure 13B: 5mM Cd²⁺, 20 μg/ml of PAA; Figure 13C: 5mM Cd²⁺, without PAA; Figure 13D: 5mM Cd²⁺, 20 μg/ml of PAA. Figures 14A-14C show a micrograph (Figure 14A) and two graphs showing XRD peaks (Figures 14B and 14C).

Figures 15A-15F are micrographs demonstrating the influence of solution concentration and polymer. Figure 15A: 10 mM Cd²⁺, 20 μg/ml of PAA; Figure 15B: 10 niM Cd²⁺, 20 μg/ml of PAA; Figure 15C: 20 mM Cd²⁺, 20 μg/ml of PAA; Figure 15D: 5 mM Cd²⁺, 20 μg/ml of PAA; Figure 15E: 5 mM Cd²⁺, 20 μg/ml of Pasp.

Figure 16 shows a schematic diagram of simple reaction apparatus to prevent the evaporation of reacting solution.

Figure 17 shows a Polarized optical microscope image of CdS precipitates after 2 days of reaction.

Figure 18 shows an X-ray diffraction pattern of CdS precipitate from reaction solution with poly-acrylic acid.

Figure 19 shows a polarized optical microscope image (with gypsum wave plate) of SAM printed on gold substrate, which reacted in the reaction solution without poly-acrylic acid for 3 days. Surface was cleaned by sonication with DI water.

Figures 2OA and 2OB show polarized optical microscope images of SAM printed on gold substrate (Figure 2OA: 50 μm; Figure 2OB: 20 micron), which reacted in the reaction solution with 20 μg/ml of poly-acrylic acid for 3 days. Surface was cleaned by sonication with DI water. Figures 21A and 21B show scanning electron microscope image (Figure 21A) of

SAM printed on gold substrate, which reacted in the reaction solution without poly-acrylic acid for 3 days. EDS data of CdS film (Figure 21B) shows the presence of Cd (Au and Si are from substrate below the thin film).

Figure 22 shows an atomic force microscope image of CdS film deposited on SAM. Figures 23A and 23B show an atomic force microscope image (Figure 23A) of CdS film on SAM (same region as in Figure 22), and line profile of film (Figure 23B). Line scanning was performed along white line in Figure 23A, and its results are shown in Figure 23B. The film is about 20 run thick. DETAILED DESCRIPTION OF THE INVENTION

The present inventors have used a biomimetic approach (PILP) to produce CdS films on self-assembled monolayers (SAMs), providing the basis for using the PILP process to produce various materials (e.g., ceramic materials). As indicated above, it has been previously been shown that the size and shape of calcium carbonate and calcium phosphate crystals can be controlled by process-directing agents, such as anionic poly-amino acids, which generate a highly hydrated amorphous precursor, called the polymer-induced-liquid- precursor (PILP) phase (Gower, L.B. and Odom, D. J., J. Cryst. Growth, 2000, 210:719-734; Gower, L. A., "The Influence of Polyaspartate Additive on the Growth and Morphology of Calcium Carbonate Crystals," Doctoral Thesis, Department of Polymer Science and Engineering, University of Massachusetts at Amherst, 1997, 1-119; Gower, L.A. and D. A. Tirrell, J. Crystal Growth, 1998, 191(l-2):153-160; Olszta et al, CaMf. Tissue Int., 2003, 72(5):583-591; U.S. Patent No. 7,090,868 (Gower et al); and U.S. Patent Application Publication Nos. 20030232071 (Gower et al), 20040131562 (Gower et al), 200501522990 (Gower et al); which are each incorporated herein by reference in their entirety).

In one aspect, the present invention provides a method for depositing a film (e.g., a semiconductor film or ceramic film) on a substrate, comprising: providing a substrate (template); contacting the substrate with a metal ion-containing solution (e.g., Cd²⁺ ion- containing solution); adding a source of Group Via element, such as sulfur ions, to the substrate (e.g., via vapor diffusion); adding an anionic polymer (e.g., poly-acrylic acid, poly- aspartic acid, etc.) as a process-directing agent; and allowing a film to form on the substrate.

The films of the invention can be formed on or applied to a substrate, e.g., as a coating or coatings.

The substrate can be composed of any of a variety of materials, such as metal, polymer, and/or ceramic materials. Suitable substrates include but are not limited to glass, fused silica, spin-coated polyimide, polycarbonate, polyester, and silicon wafers. When manufacturing integrated circuits, for example, patterns are successively transferred from photo masks reticles into photosensitive resist layers formed on substrates, e.g., semiconductor wafers, which are then post-processed in order to transfer the pattern further into an underlying layer. With the continued increase of structure densities to be accomplished on the wafer, the resolution capability requirements of the photo masks have increased. Therefore, resolution enhancement techniques such as alternating or attenuated phase shift masks, etc., are employed in semiconductor manufacturing. In preferred embodiments, the substrate is a self-assembled monolayer (SAM) patterned by soft lithography. The films may be easily patterned on a surface using standard photolithographic and soft lithographic techniques, enabling multiple fields containing different molecular assemblies to be deposited. InkJet printing and automated (robotic) techniques that can precisely deposit small spots of material on a substrate may also be exploited to pattern the surface. Practically any substrate, including all classes of materials, e.g., metals, ceramics, glasses, non-crystalline materials, semiconductors, polymers and composites, may be used or adapted for use with the invention. Substrates may also be combined; for example, a substrate of one material may be coated or patterned with a second material. Such coatings may be desirable to provide a specifically tailored set of bulk and surface properties for the substrate. It is not necessary to coat the entire substrate with the second material. The second material may be deposited according to a periodic or other pattern. For example, an electrical circuit may be deposited on the material. The substrates may also be pretreated before deposition of the film. A range of methods are known in the art that can be used to charge, oxidize, or otherwise modify the composition of a surface if desired, including but not limited to plasma processing, corona processing, flame processing, and chemical processing, e.g., etching, micro-contact printing, and chemical modification. Optical methods, such as UV or other high energy electromagnetic radiation or electron beams, may also be employed.

The substrate may include an anchor group that facilitates molecular self assembly. Anchor groups form chemical bonds with functional groups on the substrate surface to form a self assembled monolayer (SAM). SAMs having different anchor groups such as silane and thiol may be deposited on a wide variety of substrates, as described in U.S. Patent No. 5,512,131 (Kumar et al). One skilled in the art will appreciate that SAMs may be deposited from both the solution and the gas phases onto the substrate. In addition, various soft lithography techniques {e.g. , microcontact printing, microtransfer molding, micromolding in capillaries, replica molding, and micro fluidics, described in Xia, et al, Soft Lithography, Angew. Chem., 1998, 37: 550-575, which is incorporated herein by reference in its entirety), may also be used.

Suitable metal salts include but are not limited to water-soluble formate, acetate, sulfate and chloride salts of Cd, Hg, Ag, Mn, Bi, Sb, As Sn, In, Pb, Cu, Co, Ni, Mo, Fe, and Cr. Cadmium is a preferred metal. Thin films of cadmium sulfide (CdS) have major applications in optoelectronic devices.

Suitable Group Via elements include O, S and Se. Suitable sources of these elements include water (for making metal oxides); thiourea, thioacetamide and Na₂S₂O₃ (for making metal sulfides); and selenourea, dimethylselenourea and Na₂Se₂O₃ (for making metal selenides). For example, S^2" can be released from thioacetamide.

One or more of a variety of anionic polymers (e.g., anionic poly-amino acids) can be utilized as a process-directing agent. Polyacrylic acid (PAA), polymethacrylates (PMA), sulfonated polymers, phosphorylated peptides and polymers, sulfated and/or carboxylated glycoproteins, polyaspartic acid, polyglutamic acid, phosphonates, polyvinyl phosphonates or copolymers thereof can be utilized to induce the liquid-phase separation, for example. A range of polymer molecular weights can be suitable if the other variables of the crystallizing conditions are appropriately modified to generate the PILP phase.

Optionally, a noble metal may be utilized in the deposition method, as described in the Examples. Useful noble metals include, for example, gold, platinum, palladium, silver, nickel, and copper.

The type of reaction vessel or vessels utilized for producing the films of the present invention, or their sizes, are not critical. Any vessel or substrate capable of holding or supporting the PILP and/or substrate so as to allow the reaction to take place can be used. It should be understood that, unless expressly indicated to the contrary, the terms "adding", "contacting", "mixing", "reacting", "combining" and grammatical variations thereof, are used interchangeable to refer to the mixture of reactants of the process of the present invention (e.g., anionic poly-amino acids, Cd²⁺ ion-containing solution, and so forth), and the reciprocal mixture of those reactants, one with the other (i.e., vice-versa). A composition comprising a hydrated amorphous phase in a metal ion solution is also provided herein. In this aspect of the invention, the hydrated amorphous phase comprises metal salts selected from water-soluble formate, acetate, sulfate or chloride salts of Cd, Zn, Hg, Ag, Mn, Bi, Sb, As Sn, In, Pb, Cu, Co, Ni, Mo, Fe, Cr, or combinations thereof, one or more Group Via element and an anionic polymer. The anionic polymer sequesters the metal salts and one or more Group Via element from the metal ion solution. Certain aspects of the invention provide metal salts selected from water-soluble formate, acetate, nitrate, sulfate or chloride salts of Cd. Various other aspect of the invention provide Group Via elements selected from O, S or Se, Te or combinations thereof and anionic polymer selected from polyacrylic acid (PAA), polymethacrylates (PMA), sulfonated polymers, phosphorylated peptides and polymers, sulfated and/or carboxylated glycoproteins, polyaspartic acid, polyglutamic acid, phosphonates, polyvinyl phosphonates or copolymers of these materials

As used herein, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to "a film" includes more than one such film, and the like. Reference to "anionic poly-amino acid" includes more than one such "poly-amino acid". Reference to Cd²⁺ ion includes more than one such ion, and so forth.

The terms "comprising", "consisting of, and "consisting essentially of are defined according to their standard meaning and may be substituted for one another throughout the instant application in order to attach the specific meaning associated with each term.

MATERIALS AND METHODS

1. SAM templates were prepared by: a. Microcontact printing SAM on gold using soft-lithography

2. Templates were placed in the solution containing Cd²⁺ ion, thiourea and triethanolamine by the following procedure: a. Templates is placed in clean petri-dish with up-side down position; and b. Two stock solutions (A, B) were prepared Solution A: 5mM of cadmium acetate and 5mM of triethanolamine Solution B: 5mM of thiourea c. Appropriate poly-acrylic acid solution (lmg/ml) was added into Petri-dish as a process-directing agent, and the final concentration of poly-acrylic acid was adjusted to 20μg/ml; and d. Equal amount of solution A and B is added to Petri-dish containing template and poly-acrylic acid; e. Petri-dish was sealed by parafilm without any hole; f. Petri-dish was placed into 65⁰C oven with water reservoir to prevent any undesirable evaporation of the reaction solution (shown in Figure 16) 3. Various concentrations of Cd²⁺ and thiourea were used to investigate CdS film deposition at room temperature.

Example 1 — CdS particle formation via PILP process using thiourea (3 days of reaction)

CdS precipitates were not formed immediately in contrast to the former result, but CdS particles were formed between 12 and 36 hours of reaction (Figure 17). It might be because incubation time is required to produce certain amount of sulfur source from thiourea.

During reaction, cubic and hexagonal CdS precipitates were co-formed from both solutions with and without poly-acrylic acid (Figure 18).

Example 2 — CdS film formation via PILP process using thiourea (3 days of reaction)

CdS film was not formed on the SAM when poly-acrylic acid was not used as a process directing agent (Figure 19). Only a few agglomerations of CdS precipitates were observed on the substrate, but not specifically templated on the SAM, and they can be easily removed by sonication with de-ionized water. However, when poly-acrylic acid was added, a very smooth and thin CdS film was deposited on the COOH-terminated SAM (Figure 20). With polarized microscope, the color of film is very uniform and color appears nearly magenta (indicating sample is isotropic), which could mean either that the CdS film on SAM is one phase, cubic CdS (which is non-birefringent), or hexagonal CdS whose optical axis is parallel to beam direction (and therefore non-birefringent). When the CdS film region (square region in Figure 21) was examined with Energy Disersive Spectroscopy (EDS) for compositional analysis, cadmium was observed. Because of the large interaction volume of the electron beam, the cadmium signal from the very thin CdS film is not intense. But. no cadmium was observed on the edge region, which is not supposed to have a SAM. It was hypothesized that liquid (hydrophilic) CdS precursors induced by PAA were deposited only on the hydrophilic SAM.

To check the smoothness and thickness of CdS film, CdS film was examined with Atomic Forces Microscopy (AFM) (Figure 22). Very smooth film was deposited on the COOH-terminated SAM and no film was observed on the edge (gold region). Small particles were also observed on the CdS film and gold region. It might be nano-particle formed from CdS precursors. A line-scan of the film indicates that the film thickness is around 20 nm (Figure 23).

As shown in this example, a smooth CdS film was deposited on the SAM via the PILP process, in which poly-acrylic acid was used to induce CdS liquid precursors and thiourea was used as a sulfur source. The CdS was deposited on the hydrophilic SAM only, and the average thickness is around 20 nm.

Example 3 — CdS formation on SAM (3 days of reaction)

On COOH-terminated SAM, a very thin CdS film was deposited. In the control experiment (without PAA), CdS patterns were not formed, and randomly dispersed particles were observed (Figures 13A-13D and 14A- 14C). It was hypothesized that CdS precursors induced by PAA were deposited on the hydrophilic SAM to form a very thin CdS film.

Example 4 — The Influence of Solution Concentration and Polymer

CdS film was deposited only from 5mM of Cd solution (Figures 15A-15F). However, uniformity of film and smoothness of surface was poor. Poly-aspartic acid did not show an ability to induce the PILP process under these conditions. Film thickness was measured by Alpha-step 500 (Tencor), and the average thickness of the CdS film was 11.3 nm.

The pH of the reacting solution was between 2-3. Because, at this range, the charge of the polymer added as a process-directing is slightly negative (PAA, dissociation ratio of PAA is around 0.1 at pH 2-3) or positive (Pasp, pKx=3.65), only PAA shows the ability of inducing PlLP. However, because very few carboxyl groups are dissociated at those ranges, pH adjustment should be made to maximize the dissociation of carboxyl group in PAA and

Pasp.

This example demonstrates that CdS films can be deposited on SAMs via the PILP process. Without polymer, CdCO₃ was formed at the air/solution interface. The average thickness of

CdS films was 11.3 nanometers. The pH range of the system was very acidic, and Pasp did not show the ability of forming CdS precursor via the PILP process at pH range 2-3; however, PAA could be used for process-directing polymer for the PILP process at low pH range.

All patents, patent applications, provisional applications, and publications referred to or cited herein, supra or infra, are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification. It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.

Claims

CLAIMSI claim:

1. A composition comprising a hydrated amorphous phase in a metal ion solution, said hydrated amorphous phase comprising metal salts selected from water-soluble formate, acetate, sulfate or chloride salts of Cd, Zn, Hg, Ag, Mn, Bi, Sb, As Sn, In, Pb, Cu, Co, Ni, Mo, Fe, Cr, or combinations thereof; one or more Group Via clement; and an anionic polymer, wherein said anionic polymer sequesters said metal salts and said one or more Group Via element from said metal ion solution.

2. The composition according to claim 1, wherein said metal salts are selected from water-soluble formate, acetate, nitrate, sulfate or chloride salts of Cd.

3. The composition according to claim 1 or 2, wherein said Group Via element is selected from O, S or Se, Te or combinations thereof.

4. The composition according to claim 1, 2 or 3, wherein said anionic polymer is selected from polyacrylic acid (PAA), polymethacrylates (PMA), sulfonated polymers, phosphorylated peptides and polymers, sulfated and/or carboxylated glycoproteins, polyaspartic acid, polyglutamic acid, phosphonates, polyvinyl phosphonates or copolymers thereof.

5. A method for depositing a ceramic film on a substrate comprising: providing a substrate; contacting the substrate with a compositon according to any of claims 1, 2, 3, or 4 and forming a ceramic film on the substrate.

6. A method for depositing a ceramic film on a substrate comprising: providing a substrate; contacting the substrate with a metal ion-containing solution; adding a source of Group Via element; adding an anionic polymer to induce/stabilize an amorphous phase comprising said metal ions and said Group Via elements; and forming a ceramic film on the substrate.

7. The method according to claim 6, wherein said amorphous phases coalesces into a smooth and continuous ceramic film or coating and crystallizes into the functional ceramic.

8. The method according to claim 6 or 7, wherein said amorphous phase is nucleated on a substrate or in solution by said anionic polymer..

9. The method according to claim 6. 7, or 8, wherein said substrate comprises metal, polymer, and/or ceramic materials.

10. The method according to claim 9, wherein said substrate is glass, fused silica, spin-coated polyimide, polycarbonate, polyester or a silicon wafer.

11. The method according to claim 6, 7, 8, 9, 10 or 11, comprising coating or patterning said substrate with a second material.

12. The method according to claim 6, 7, 8, 9, 10 or 11, wherein the substrate comprises a self-assembled monolayer (SAM) patterned by soft lithography.

13. The method according to claim 6, 7, 8, 9, 10, 11 or 12, wherein said second material is deposited according to a periodic or other pattern onto said substrate.

14. The method according to claim 6, 7, 8, 9, 10, 11, 12 or 13, wherein said substrate comprises a self assempled monolayer comprising anchor groups, alkyl chains and functional head groups that facilitate molecular self assembly into a self assembled monolayer (SAM).

15. The method according to claim 14, wherein said anchor groups are silane or thiol groups.

16. The method according to claim 14 or 15, wherein the head groups comprise alcohol, carboxylic acid, phosphate, amine or sulfate groups.

17. The method according to any preceding claim, wherein said metal ion solution comprises salts selected from water-soluble formate, acetate, sulfate or chloride salts of Cd, Zn, Hg, Ag, Mn, Bi, Sb, As Sn, In, Pb, Cu, Co, Ni, Mo, Fe, Cr, or combinations thereof.

18. The method according to claim 17, wherein said metal salts are selected from water-soluble formate, acetate, nitrate, sulfate or chloride salts of Cd.

19. The method according to any preceding claim, wherein said Group Via element is selected from O, S or Se, Te or combinations thereof.

20. The method according to any preceding claim, wherein said anionic polymer is selected from polyacrylic acid (PAA), polymethacrylates (PMA), sulfonated polymers, phosphorylated peptides and polymers, sulfated and/or carboxylated glycoproteins, polyaspartic acid, polyglutamic acid, phosphonates, polyvinyl phosphonates or copolymers of these materials

21. The method according to claim 6, wherein said film is cadmium sulfide (CdS), said metal ion is Cd and said Group VI element is S.

22. The method according to claim any preceding claim, said method comprising the deposition of a noble metal on said provided substrate prior to, or after, contacting said provided substrate with a metal ion-containing solution.

23. The method according to claim 22, wherein said noble metal is gold, platinum, palladium, silver, nickel, or copper.

24. The method according to claim 11 or 13, wherein said second material is a noble metal.

25. A film coated substrate produced by the method of any of claims 5, 6, 7, 8, 9, 10,, 12, 13, 14, 15, 16 17, 18, 19, 20, 21, 22, 23 or 24.