SBIR Phase I: High Efficiency Thin Film Photovoltaics

This Small Business Innovation Research (SBIR) Phase I project aims to demonstrate the feasibility of virtual single crystal (VSC) technology for high-efficiency, low-cost and flexible CdTe solar cells. Wakonda has previously showed epitaxial deposition of CdTe on a flexible VSC metal foil, resulting in CdTe films with large (~ 50 microns) and highly-oriented crystalline grains. This project will develop the technology to achieve optimized carrier concentrations in p- and n-type CdTe on VSC through non-equilibrium methods. It is expected to lead to flexible CdTe solar cells with efficiencies at or above 15%. The broader/commercial impact of this project will be the potential to reduce the manufacturing cost of solar modules in the building-integrated photovoltaics (BIPV) market, which is projected to exceed $1.7 billion by 2011. The VSC approach by Wakonda will enable the production of high-crystallinity CdTe films at low cost by using industrial-standard roll-to-roll manufacturing equipment. This project will also advance the science and technology of CdTe and other II-VI materials that are known to have high intrinsic material defects that limit free carrier concentrations and minority carrier lifetimes. This knowledge could impact other existing and future II-VI optoelectronic devices.