Spatially resolved opto‐electrical performance investigations of Cu 2 ZnSnS 3.2 Se 0.8 photovoltaic devices

摘要

A new statistical analysis of spatially resolved photocurrent and electroluminescence images has been developed and applied to Cu 2 ZnSn(S x Se 1? x ) 4 (CZTSSe) monograin solar cells. CZTSSe as an absorber material has the potential to significantly reduce manufacturing costs and develop new application fields in photovoltaics. Deep understanding of the performance related parameters in various production steps is crucial for further development of the technology. In this paper we show that by a thorough investigation by means of a combination of opto‐electrical measurement methods such as light beam induced current mapping, scanning electron microscopy, optical microscopy, photoluminescence, and electroluminescence measurements a correlation with different current‐voltage ( j / V ) measurement parameters can be established. Hereby, we clearly identify barrier variations at the active interface as the main reason for current variations across the cell, which for record cells can largely be avoided. These variations show up clearly in the microscopic spatial analysis developed. The detailed analysis of the homogeneity of the solar cell photocurrent presented in this study is relevant for all kinds of solar cells including thin‐film and wafer‐based cells.