Analyzing the effects of CSVT growth parameters on deposition of CdSe thin films

Abstract

Close spaced vapor transport (CSVT) is a vital component of the CdTe thin film photovoltaic industry. A material with a similar structure, CdSe, shows great promise for the development of thin film photovoltaic cells as well, particularly in a tandem cell with high efficiency Si. Utilizing a custom made CSVT system, we analyzed the film quality of thin CdSe on FTO and CdS and compared the electrical properties of photovoltaic cell created with CSVT CdSe to cells consisting of thermally grown CdSe in the same configuration. After the films were deposited, we explored the CdCl_2 treatment, and its effects on grain size and electrical properties of photovoltaic devices. When compared to the optimized thermally evaporated (TE) CdSe of comparable thickness, the CSVT films initially had larger grains and resulted in devices with higher efficiencies; However, CSVT films do not see as significant of an improvement from the CdCl_2 treatment, and thus their photovoltaic cells have a significantly lower efficiency than comparable TE cells after the treatment.