Preparation And Characterization Of CuInS₂ Films By Chemical Deposition Method

Based on the preparation of lead sulfide mineralization (PbS), a new system of preparing inorganic functional materials by chemical deposition with solution as medium was constructed. Inorganic material film can be prepared in the solution surroundings at normal temperatures and pressures in this method. Firstly, the In₂S₃/Cu₂S composite films were prepared under mild conditions, and the composite films were annealed in S atmosphere to obtain the CuInS₂ thin film materials. The effect of annealing temperature on the morphology, structure and optical property were researched. The results show that the method is different from the previous film preparation methods, which reduces the requirement for equipment and simplifying the technical complexity, providing an effective method for the preparation of CIS thin film materials with low cost.The thesis includes the following parts:1. Deposition of In₂S₃/Cu₂S composite films with two steps and preparation and research on performance of CuInS₂ thin films.In₂S₃ and Cu₂S with good orientation were prepared at the gas-liquid interface with BSA used as organic template and ammonia diffusion introduced to catalyze the hydrolysis of TAA. Though this kind of materials have good structural characteristic, the thickness of this kind of materials is too thin, and bonding with the substrate is poor and it is hard to form large orderly composite film. These characteristics make them difficult to subsequent vulcanization annealing. Meanwhile we find that a uniform and compact thin film of In₂S₃ can be easily formed in the bottom of trough. Based on this, a uniform and compact In₂S₃, Cu₂S thin film was firstly deposited using a chemical deposition method, and then the Cu₂S thin film was deposited on the surface of In₂S₃ thin film, forming a uniform compound film of In₂S₃/Cu₂S. The composite thin films were treated through the vulcanization annealing processing, CuInS₂ films formed. The influence of annealing temperatures on the film morphology, structure and optical properties was studied in detail. The results show that, with the increase of annealing temperature, the film gradually changes from flakes into particles, and the crystalline phase of Cu₂S, In₂S₃ in films disappeared gradually, the crystallinity and grain size increases gradually. The absorption in visible light region becomes wider, and the band gap of materials has obvious change.2. Deposition of In₂S₃/Cu₂S composite films with one step and preparation and characterization of CuInS₂ thin films.In the second section, the composite thin films of Cu₂S/In₂S₃ was deposited in two steps, the procedure is complex comparatively. In the third section, we tried to prepare the composite thin films of Cu₂S/In₂S₃ in one step. Firstly the composite thin film of Cu₂S/In₂S₃ was deposited in a mixed solution of three hydrated nitric acid copper, thioacetamide and indium sulfate. The composite thin films were treated through the vulcanization annealing processing, forming CuInS₂ films. The effect of annealing temperatures on the morphology, structure and optical property was also studied. The results show that the film presents a chalcopyrite structure. With the increase of annealing temperature, the crystallization increases and the grain size increases gradually. The absorption in visible light region becomes wider, and the band gap of materials decreases. Since t the adhesion is poor and the reaction is too long, the reaction temperature was increased to 45 oC. The composite thin films were obtained in two hours, and the CuInS₂ thin films with chalcopyrite structure were fabricated after vulcanization annealing processing.