SBIR Phase I: Low-Cost, Copper-Based Metallization Pastes for Solar Cell Applications

This Small Business Innovation Research (SBIR) Phase I project will study the feasibility of using abundant elements in metallization pastes for crystalline silicon solar cells. Currently, silver-based pastes dominate the market because they do not oxidize and can be processed at high temperatures. Unfortunately, these pastes contain a large fraction of silver (e.g.>50%), which is a precious metal that currently costs ~$1000/kg. During this feasibility study, PLANT PV will attempt to synthesize and fabricate low-cost thin films of composite metal particles made from abundant elements that can be used as a replacement for Ag-pastes. In order to achieve success, the films must be sufficiently conductive and strongly adhere to the silicon solar cell while not reducing the overall power conversion efficiency. The broader impact/commercial potential of this project will be a significant reduction in the overall cost of PV cell processing. Currently PV modules cost $0.70-0.80/W to produce with roughly $0.08/W cost coming from the silver based metallization pastes. The global silver paste market in the PV industry is>$1.8 bn/year. We believe that by switching to non-silver alternatives it is possible to provide significant cost reductions (e.g.>$0.05/W). Module cost reductions have primarily driven the significant growth in solar cell installations in the United States in the past five years. While PV is now cost competitive in several regions in the US, further solar module reductions to $0.50/W, with commensurate reductions in installation costs, would make solar power cost competitive with>1TW of power production in the US without subsidies. Finally, metallization pastes developed in this Phase I study may have applications in a wide range of products including displays and integrated circuits.