STTR Phase I: Feasibility Demonstration & Performance Optimization of an Ultra-High-Efficiency, Thin-Film, Crystalline Si Solar Cell for Cost-Effective, Grid-Connected Electricity

This Small Business Technology Transfer (STTR) Phase I research project addresses the rapidly growing world-wide solar energy market, by demonstrating, optimizing, and commercializing an ultra-high-efficiency and ultra-low-cost solar cell / module technology. Expensive and unreliable fossil fuel supplies and escalating global demand for energy have created the need for an alternate, widely available, cost-effective, and renewable source. Key solar attributes are the abundant, worldwide, point-of-use supply of sunlight and its environmental friendliness. The goal of this project is to reduce solar electricity cost for grid-connected electricity markets by implementation of an innovative ultra-high-efficiency cell and module designs with a low material usage & cost-reduced manufacturing, while leveraging the maturity and environmental acceptance of Si PV. This project is expected to result in efficiencies higher than best-of breed crystalline Si-wafer cells. The team's approach improves the cell & module structures, resulting in enhanced efficiency & reduced cost. The proposed solution includes: (1) a significant reduction of Si consumption; (2) optimal cell design for ultra-high cell & module efficiencies; (3) low-cost super-selfaligned cell fabrication; (4) decreased consumption of fab materials; (5) unique module design & assembly, enabling fab automation; (6)) reduced performance gap between the cell & module efficiencies due to higher area utilization & lower ohmic losses; (7) reduced labor cost; and (8) cell technology based on 50+ years of Si-based learning and a mature manufacturing supply chain. The PV market (~$1.5B in 2005) will grow 35+% CAGR to >$35B by 2010, indicating the market-pull for cost-effective solutions. This project provides the following global benefits: (1) cost-effective solar modules to meet industry roadmap for affordable, secure, distributed electricity; (2) environmentally-benign solar cell & module materials and fab processes for sustainable environment; (3) shortened energy payback time to 400 kg/year (or by >12,000 kg over the minimum 30-year lifetime of PV systems). This project will make a measurable contribution to an expanding U.S.-based solar energy technology and fab infrastructure for grid-connected PV markets. It is the intent of this project to reduce cost by implementation of an innovative ultra-high-efficiency solar cell and module with simplified manufacturing while retaining the high-efficiency of crystalline Si PV. This project will serve as the precursor for establishing a cascade of U.S.-based PV fabs with production volumes scaled from 2.5 MWp to 100+ MWp over 4 years, making significant projected contributions to the U.S.-based PV manufacturing infrastructure and creation of U.S.-based jobs.