Influence of heat treatment and back contact processing on the performance of CdS/CdTe thin film solar cells produced in a CSS in-line system

► CdTe photovoltaic cells were grown continuously in a homemade CSS system. ► The maximum efficiency of CSS cells was 7%. ► Photocurrent and fill factor were affected by the heat treatment and back contact. ► CSS cells treated and contacted at NREL showed efficiencies in the 10-11% range. ► Comparison between procedures helped to identify critical issues in CSS process.