Effects of Ar and He atmosphere on CdTe thin film deposition and CdTe solar cell performance

摘要

Properties of polycrystalline CdTe thin film deposited under Ar and He co ntaining atmosphere respectively as well as the performance of solar cells based on them were compared to evaluate the potential of substituting He by more economical Ar during CdTe deposition. CdTe thin films were grown in Ar-O 2 and He-O 2 mixture atmosphere by close space sublimation method. CdTe thin films of the same thickness deposited under varied atmosphere didn't sho w substantial property divergence, except that the deposition rate almost doubled under He containing ambience than that under Ar at the same deposition temperature. Low-temperature nucleation, sublimation and thermal convection model were introduced to interpret the large deposition rate difference under different atmosphere. Ar-atmosphere deposited CdTe solar cells had better performance than He counterpart and t he optimized one showed high efficiency of 16.09%. It is highly enco uraging to replace He by Ar during CdTe deposition.