Study On Process And Performance Of Aluminum Induced Polycrystalline Silicon Film

Due to the increased consumption of fossil fuels and the increase in environmental pollution,the photovoltaic industry has become one of the fastest growing industries.As one of the silicon-based thin film solar cells,polycrystalline silicon cells have low preparation cost and high photoelectric conversion efficiency,having the advantages of both amorphous silicon and single crystal silicon batteries.The aluminum induction crystallization method is one of the most commonly used methods for producing polycrystalline silicon.Therefore,the research on the process of aluminum induction and the deeper process mechanism research have important significance in the field of photovoltaic cell industry.In this paper,the composite film structure substrate-Al-Al2O3-?-Si required for polysilicon plating is prepared by aluminum induction method.The previous study,different from the predecessors,used the natural oxidation method to prepare the intermediate transition layer Al2O3.This method is not accurate in controlling the thickness of the intermediate transition layer and the density of the film layer.In this study,the intermediate transition layer was coated by magnetron sputtering to improve the credibility of the aluminum induced crystallization process.At the same time,this study uses FJL560CII magnetron sputtering system(RF power supply,DC power supply)and PVD12512 magnetron sputtering system(intermediate frequency power supply)to conduct experiments with different methods for different problems.The performance of the sample was characterized by multiple means such as step profiler,Xray diffractometer,Raman spectroscopy and scanning electron microscopy.Starting with the whole process of aluminum induced crystallization,this paper studies the selection of substrate type,substrate temperature and coating equipment before preparation,the optimization of sputtering power of each layer during preparation,the thickness of intermediate transition layer and other process parameters,as well as the characterization and analysis of adhesion and residual components of the finished film after preparation.The ideal substrate material and substrate temperature were selected by experiments and measurements.The process of reactive layer,intermediate transition layer sputtering power and intermediate transition layer thickness during film preparation were optimized,providing a reference for the preparation process of polycrystalline silicon thin film batteries.The film layer bonding after adding intermediate transition layer was analyzed.The reason for the decrease in force and the conclusion obtained by first-principles calculations.The low-concentration Aldoped polysilicon film was designed to prepare the Si film with the same residual content of Al in the finished polysilicon.The behavior of not easily oxidized for residual elements is proved through the detection and first-principles calculation,and the mechanical properties such as internal stress and elastic modulus of polysilicon film layers under different residual element concentrations are discussed.Theoretical support is provided for the performance improvement of the polycrystalline silicon finished film prepared by the aluminum induced crystallization method.