ZnS nanostructures: From synthesis to applications

CuO nanostructures: Synthesis, characterization, growth mechanisms, fundamental properties, and applications

During last three decades, successive ionic layer adsorption and reaction (SILAR) method, has emerged as one of the solution methods to deposit a variety of compound materials in thin film form. The SILAR method is inexpensive, simple and convenient for large area deposition. A variety of substrates such as insulators, semiconductors, metals and temperature sensitive substrates (like polyester) can be used since the deposition is carried out at or near to room temperature. As a low temperature process, it also avoids oxidation and corrosion of the substrate. The prime requisite for obtaining good quality thin film is the optimization of preparative provisos viz. concentration of the precursors, nature of complexing agent, pH of the precursor solutions and adsorption, reaction and rinsing time durations etc. In the present review article, we have described in detail, successive ionic layer adsorption and reaction (SILAR) method of metal chalcogenide thin films. An extensive survey of thin film materials prepared during past years is made to demonstrate the versatility of SILAR method. Their preparative parameters and structural, optical, electrical properties etc are described. Theoretical background necessary for the SILAR method is also discussed.

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Deposition of metal chalcogenide thin films by successive ionic layer adsorption and reaction (SILAR) method

Many techniques for the synthesis of ceramic thin films from aqueous solutions at low temperatures (25–100°C) have been reported. This paper reviews non-electrochemical, non-hydrothermal, low-temperature aqueous deposition routes, with an emphasis on oxide materials for electronic applications. Originally used for sulfide and selenide thin films, such techniques have also been applied to oxides since the 1970's. Films of single oxides (e.g., transition metal oxides, In2O3, SiO2, SnO2) and multicomponent films (doped ZnO, Cd2SnO4, ZrTiO4, ZrO2-Y2O3, Li-Co-O spinel, ferrites, perovskites) have been produced. The maximum thicknesses of the films obtained have ranged from 100 to 1000 nm, and deposition rates have ranged from 2 to 20,000 nm/h. Compared to vapor-deposition techniques, liquid-deposition routes offer lower capital equipment costs, lower processing temperatures, and flexibility in the choice of substrates with respect to topography and thermal stability. Compared to sol-gel techniques, the routes reviewed here offer lower processing temperatures, lower shrinkage, and (being based on aqueous precursors) lower costs and the potential for reduced environmental impact. This review emphasizes the influence of solution chemistry and process design on the microstructures and growth rates of the films. The current understanding of the mechanisms of film formation is presented, and the advantages and limitations of these techniques are discussed.

Review: Deposition of ceramic thin films at low temperatures from aqueous solutions

The oxides of copper (CuxO) are fascinating materials due to their remarkable optical, electrical, thermal and magnetic properties. Nanostructuring of CuxO can further enhance the performance of this important functional material and provide it with unique properties that do not exist in its bulk form. Three distinctly different phases of CuxO, mainly CuO, Cu2O and Cu4O3, can be prepared by numerous synthesis techniques including, vapour deposition and liquid phase chemical methods. In this article, we present a review of nanostructured CuxO focusing on their material properties, methods of synthesis and an overview of various applications that have been associated with nanostructured CuxO.

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Nanostructured copper oxide semiconductors: a perspective on materials, synthesis methods and applications

Chemically deposited copper oxide thin films: structural, optical and electrical characteristics

We demonstrate the deposition of ZnS thin films with a thickness of 0.04 to m at temperatures ranging from 25 to C from chemical baths comprising zinc sulphate, triethanolamine and thioacetamide at pH of about 10. The as-deposited films do not show crystallinity, are very resistive (conductivity ) and possess no photosensitivity. Annealing of the films in air at 450 to C for 1 - 2 h leads to partial conversion of the ZnS films to ZnO films. This is accompanied by an increase in the photoconductivity by more than six orders of magnitude. The optical bandgap is >3.85 eV in the as-prepared films; after annealing in air the value drops to about 3.7 eV.

https://iopscience.iop.org/article/10.1088/0268-1242/12/10/022/pdf

Chemical bath deposition of ZnS thin films and modification by air annealing

Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8 eV for Sb2S3, and 1.35 eV for Sb2Se3. As deposited, all the films are nearly amorphous. However, well defined crystalline peaks matching bismuthinite (JCPDS 17- 0320), paraguanajuatite (JCPDS 33-0214), and stibnite (JCPDS 6-0474) and antimony selenide (JCPDS 15-0861) for Bi2S3, Bi2Se3, Sb2S3 and Sb2Se3 respectively, are observed when the films are annealed in nitrogen at 300 degrees Celsius. This is accompanied by a substantial modification of the electrical conductivity in the films: from 10-7 (Omega) -1 cm-1 (in as prepared films) to 10 (Omega) -1 cm-1 in the case of bismuth sulfide and selenide films, and enhancement of photosensitivity in the case of antimony sulfide films. The chemical deposition of a CuS/CuxSe film on these Vx- VIy films and subsequent annealing at 300 degrees Celsius for 1 h at 1 torr of nitrogen leads to the formation of p-type films (conductivity of 1 - 100 (Omega) -1 cm-1) of multinary composition. Among these, the formation of Cu3BiS3 (JCPDS 9-0488) and Cu3SbS4 (JCPDS 35- 0581), CuSbS2 (JCPDS 35-0413) have been clearly detected. Solar energy applications of these films are suggested.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

The feasibility of producing safety glass made from 3 mm sheet glass coated with chemically deposited CuS, ZnS-CuS, Sb2S3-CuS, and PbS-CuS thin films are presented. The coatings are produced on the sheet glass from dilute solutions containing metal complexes and a source of sulfide ions such as thiourea, thioacetamide, or thiosulfate. Films of thickness ranging from 0.05 micrometer to 0.3 micrometer are deposited at different temperatures, 10 degrees Celsius - 50 degrees Celsius, with durations of depositions of 1 h to 6 h. These coatings are laminated using commercially available poly(vinyl butyral) based laminating polymer sheets and clear sheet glass at temperatures of 120 degrees Celsius to 140 degrees Celsius under 10 - 12 kg cm-2 pressure in an autoclave. The optical transmittance and reflectance spectra of the safety glasses show that a wide choice of solar control parameters are possible with these glazings: TVIS, 2.5 - 45%; RVIS, 10 - 25%; and shading coefficient (SC), 0.25 - 0.45.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Olga L Arenas

Papers

Chemically deposited copper oxide thin films: structural, optical and electrical characteristics

Chemical bath deposition of ZnS thin films and modification by air annealing

Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

Laminated solar-control safety glass incorporating chemically deposited metal chalcogenide thin films

Thermal-annealing-induced effects in chemically deposited cobalt sulphide thin films