Photovoltaic Cz Silicon Module Improvements: Annual Technical Progress Report, 9 November 1996-8 November 1997

This report describes work done by Siemens Solar Industries (SSI) during Phase II of a 3-phase Photovoltaic Manufacturing Technology (PVMaT) 4A subcontract from DOE/NREL. The work focuses on improvements in the cost per watt of Cz silicon photovoltaic modules through detailed understanding of their cost structure, module design to minimize cost per watt, measures to improve manufacturing yieldand productivity, and manufacturing control systems to improve module reliability. During this phase of the contract, SSI researchers deployed new module designs, realized improvements in yield of over 10%, and achieved further implementation of statistical process control. Module configurations representing a 12% cost reduction per watt were implemented in small-scale production. Yieldimprovements are described in detail, yield sensitivity to wafer thickness is quantified, and the deployment of statistical process control in critical process steps is reported here.