Implications of modified simplified hybrid process on CIGS devices and minimodules

The simplified hybrid (SH) process is the platform on which EPV Solar will develop a cost effective CIGS module manufacturing process. We have already implemented the SH process in our large area deposition system. In this report optimization of the Na access to the absorber layer was done by controlling the Cr underlayer thickness. In addition, CIGS process parameters have been modified to get a more uniform layer attaining good efficiency throughout the substrate at lower temperature. This helped us to make minimodule using our existing equipment design. Post-CIGS treatments of samples to passivate the surface before CdS chemical bath deposition have improved our earlier samples. However, this has been found to be less beneficial for newly processed samples reducing the overall processing steps. A textured ZnO window layer deposited on the buffer layer increased device Jsc by 5% by reducing reflectance of incident light.