SSI began a 3-year, 3 phase cost-shared subcontract (No. ZN-1-19019-5) on May 1, 1991 with the overall project goal of fabricating a large area, stable, 12.5% aperture efficient encapsulated CIS module by scaleable, low-cost techniques on inexpensive substrates. Subcontract accomplishments were facilitated by addressing module reproducibility issues using small area test devices and mini-modules. Statistical process control disciplines were adopted to rigorously quantify process reproducibility. SSI addressed uniformity and reproducibility of absorber formation, interactions of the substrate with the absorber, and performance losses near interconnects. Subcontract accomplishments included demonstration of encapsulated module efficiencies that were at that time the highest reported mini-module efficiencies for any thin film technology (encapsulated 12.8% efficient mini-module on 68.9 cm 2 and an NREL-verified 12.7% efficient unencapsulated circuit on 69 cm 2 with a prismatic cover), demonstration of a champion large area (3860 cm 2 ) encapsulated module efficiency of 10.3% that was the first thin film module of its size to exceed the 10% efficiency level, and delivery to NREL of a one kilowatt array of large area (~3890 cm From September 1995 through December 1998, SSI participated in a 3-year, 3 phase cost-shared TFPPP subcontract (No. ZAF-5-14142-03). The primary objective of this subcontract was to establish reliable high-throughput, high-yield thin film deposition processes in order to make CIS a viable option for the next generation of photovoltaics. Outdoor testing, accelerated environmental testing, and packaging development progressed throughout all phases of this subcontract. During Phase 1, SSI rigorously demonstrating process reproducibility and yield for a 10x10-cm monolithically interconnected "mini-module" baseline process and demonstrated a 13.6% aperture area efficient mini-module. During Phase 2, SSI demonstrated the need to replace an existing large area reactor with a reactor based on a more direct scale-up of the baseline reactor, built a new large area reactor, and demonstrated comparable performance for the mini-modules baseline and larger 28x30-cm circuit plates. SSI developed products and prototype large area modules using a new package designed to integrate small circuit plates into larger modules. A one kilowatt array of Cu (In,Ga)(S,Se) 2 modules was delivered to NREL replacing a previously installed array based on an older absorber formation technology without sulfur incorporated in the absorber (Cu(In,Ga)Se 2 ). This array demonstrated significant improvements in efficiency and the temperature coefficient for power. SSI introduced two new 5-watt (ST5) and 10-watt (ST10) CIS-based products designed for use in 12 V systems, and NREL confirmed a new world-record efficiency of 11.1% on a SSI large area (3665 cm 2 ) module. During Phase 3, substrate size was scaled from ~30x30 cm to ~30x120 cm and good process control was demonstrated with an average efficiency of 10.8%. Commercial produc...