Studies On Doping Properties Of RE Ions Implanted CdTe Thin Film Obtained Via CSS

Owing to its optoelectronic and chemical properties,CdTe is an ideal absorber material for high-efficiency, lowcost polycrystalline thin film. The thesis summarizes the applied foreground and development case of CdTe solar energy cells and investigates characteristics of rare earth (RE) elements doped CdTe thin film as an absorber material of solar energy cells.We have achieved continuous,compact films using a homemade CSS system.The average grain sizes of CdTe films are over 10μm. However,the pure CdTe films have high electrical resistivity and this is mighty unfavourable to improve the conversion efficiency of CdTe solar energy cells, and the best way is to doping donor or acceptor in pure CdTe films.The ion implantation is used to optimize the material.We have discussed effects of the varing doses of Er ions on the structural,optical and electrical properties of the CdTe films deposited on Si substrate. Here the conductance,carrier concentration and hall mobility ect parameters of Er doped CdTe films have been given.Using Seto model,we calculate the grain-boundary barrier of Er doped CdTe films and analyze the varing dose influence on the grain-boundary resistance.According to the results of Ramman and XRD spectrum,the structural and Ramman characteristics of 5×1014cm-2 Dy ions implanted CdTe films deposited on ceramic substrate have been studied,and the function of the thermal annealing have been discussed. It is believed that the implantation induced damage are better removed after thermal annealing and the CdTe films Ramman activity and crystalline characteristic are improved.