| Solar energy is a kind of new energy with clean, environmental protection, and reproducible properties. It is available for humankind to solve energy sources on condition that turn the solar energy into electric power. Among the various solar cells, the CIS series thin films solar cells have the advantages of high conversion efficiency, stable performance et al, possessing large-scale application potential. But more than 30 years' continuous research have not yet realized the large-scale industrialization, resulting from the high cost of current CIS solar cells due to the complex technology and expensive equipments. From the various processing methods, the electrodeposition technique, having many advantages such as simple equipments, small investment, cost-effective, effortless large-scale industrial processes, is a promising method to realize large area output of the CIS series solar cells. According to the advantages and the existing problems of electrodeposition, we attempt to carry out the following two parts of the work:1. the research of components, structure and electro-optical properties of CuInSe2 thin films prepared by electrodepositionCuInSe2 thin films were prepared by potentiostatic electrodeposition on ITO substrate and their composition, morphology, structure and photoeletric properties were analyzed, and the effect of deposition potential, solution concentration, pH value were discussed. the deposition conditions of copper-rich and indium-rich films and their corresponding photoelectric properties were analyzed. The results showed that indium-rich film has a strong opto-electrical response; the existing Cu-Se phase produce a new interface in these copper-rich films and electron-hole pairs recombine at interfaces so that the optic-electrical response is strongly depressed.2. Electrodeposition preparation and performance characterization of CIGS thin filmsCIGS thins films was prepared by potentiostatic electrodeposition in alcohol solution on ITO glass substrate and their morphologies,compositions,crystal structure and absorption properties have been characterized respectively by scanning electron microscopy (SEM), X-ray energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and UV-visible near infrared spectrophotometer (UV-VIS-NIR). Results showed the CIGS films fabricated at pH=2.0 accord with standard stoichiometric. The chalcopyrite structure CuIn0.7Ga0.3Se2 thin films can be obtained deposited at -1.6 V (vs SCE) and thereafter annealed at 450℃. The particle-films of CIGS thin films become discontinuous when annealing temperature rises above 450℃. we also found that, ethanol as solvent can effectively avoid the hydrogen evolution phenomenon which often occur at over potential deposition in hydrosolvent, and greatly reduced the deposition potential limitations, extended the types of deposited elements. The system is promising to present an new method for preparing CuIn1-xGaxSe2 thin films or other new functional materials.
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