Polycrystalline CdTe solar cells on buffered commercial TCO-coated glass with efficiencies above 15%

EPIR Technologies, Inc. reports the production of thin film polycrystalline CdTe devices with National Renewable Energy Laboratory (NREL)-verified efficiencies above 15%. While previous reporting of high efficiency poly-CdTe solar cells utilized high-temperature technical glass, EPIR´s cells were produced on commercially-available conductive glass. The devices exhibit fill factors up to 77% and short-circuit current densities around 24 mA/cm². EPIR developed a robust process for producing thin film CdTe solar cells through implementation of a high resistivity SnO₂ buffer layer and optimization of the CdS window layer thickness. The effects of the high resistivity buffer layer on device performance were investigated, demonstrating improved overall performance and yield. To our knowledge, these are among the highest efficiencies yet reported and NREL-verified for a thin film CdTe solar cell fabricated using commercial conductive glass.