SBIR Phase I: Cost-Effective, High Volume Emitter Wrap Through Manufacturing Process Development for Higher Efficiency Crystalline Silicon Solar Cells

This Small Business Innovation Research (SBIR) Phase I project aims to develop a practical manufacturing process and the key enabling hardware for Emitter Wrap Through (EWT) solar cells. EWT technology is significant because it can improve the efficiency of crystalline-silicon solar cells to potentially above 20% energy conversion efficiency from the current 13-17% today. However, its promise has not been materialized because of the challenges in processing speed and cost. This project will utilize a recently developed high-power fiber laser technology based upon Arbor Photonics 3C optical fibers, along with fast beam scanning technology to enable the development of an economical and deployable process for EWT application. The expected outcome of this project is the development of a detailed baseline laser system that can achieve more than 10,000 holes per second in a cost-effective manner. The broader/commercial impact of this project will be the potential to enable the wide adoption of EWT solar cells. The commercialization of EWT solar cells has not been realized due to the high manufacturing costs resulting from slow processing speeds that is currently less than 4,000 holes per second. The currently available commercial lasers cannot achieve the combination of pulse energy, duration and repetition rate to achieve the target of more than 10,000 holes per second required to make this process economically viable. A combination of recently developed high-power fiber laser technology from Arbor Photonics that extends the range of available operating laser parameters and fast beam scanning technology can enable development of an economical and deployable process for this application. The resulting process tool has the potential to address a portion of the $100 million market for laser-based tools used in Si solar cell manufacturing, a market segment that has seen year over year growth on the order of 60% per year in the last 5 years.