CIS-Based Thin Film PV Technology: Phase 2 Technical Report, October 1996 - October 1997

This report describes work performed during Phase 2 of Siemens Solar Industries' (SSI) subcontract. Studies of the differences between reactors continued, resulting in adjustment of most of the process conditions to more closely mimic process conditions in the baseline reactor, thereby mitigating most of the process differences. SSI designed and built a new large-area reactor that is amore-direct scale-up of the baseline reactor. This reactor became operational during Phase 2 and was successfully demonstrated by initial circuit performance for 28-cm x 30-cm circuits averaging 10.6%, which compares favorably to the 10-cm x 10-cm baseline. SSI also defined a package for introductory products in support of the DOE long-term goal of systems that last at least 30 years. SSI alsointroduced two new CIS-based products: the product designations are ST5 and ST10, which are 21-cm x 33-cm/5-watt and 39- cm x 33-cm/10-watt modules designed for 12-V systems. NREL reports 9.6% aperture- area efficiency on the samples (11.2% circuit-plate aperture area), which is the highest efficiency of any commercial noncrystalline module. SSI also delivered a set of modules to NREL for a 1-kWarray replacing an existing 1-kW array based on an older absorber formation technology. NREL reports stable performance and an unprecedented average efficiency of over 9%. A champion module was confirmed by NREL to produce 40.6 watts for a new world-record efficiency of 11.1% on 3665 cm2. This demonstrated efficiency exceeds the 1995 DOE efficiency goal for CIS prototype modules and exceeds theyear 2000 efficiency goals for amorphous silicon and cadmium telluride technologies.