Manufacturing of High-Efficiency Bi-facial Tandem Solar Cells
E.J. Tobin, S.J. Wojtczuk, E.D. Gagnon, R.G. Little
Spire Semiconductor, US
Keywords: photovoltaic, solar cell, concentrator, CPV, tandem, manufacturing
Abstract:Spire Corporation has been involved in the photovoltaic (PV) industry for over 30 years, and currently supplies leading manufacturers with equipment and training to successfully manufacture PV modules. Spire was a pioneer in solar technology, developing PV cells with record efficiencies as well as advanced thermal photovoltaic (TPV) devices. The company’s research and development activities in this area have led to over 60 granted patents in the solar space. Spire Semiconductor, LLC, a wholly owned subsidiary of Spire Corporation specializing in wafer epitaxy, foundry services, thin film products, device fabrication, and compound semiconductor products, is currently developing a highly efficient GaAs concentrator photovoltaic (CPV) cell under a National Renewable Energy Laboratory (NREL) contract. The cell is a bi-facial III-V tandem CPV cell that incorporates nanometer-scale dislocation-reducing grading layers and employs unique processes to improve manufacturing efficiencies and lower costs. The target efficiency for this triple junction GaAs-wafer-based cell is 42% at 500x concentration. A provisional patent has been submitted for the technology, and Spire intends to evaluate applicability for conventional terrestrial solar cells and space-based solar cells as well. Spire is seeking early collaboration with system manufacturers to customize and optimize cell properties for specific systems and applications. The presentation will discuss the cell structure, manufacturing processes, advantages, and current development status of the technology.