Growth of 1-eV GaNAsSb-based photovoltaic cell on silicon substrate at different As/Ga beam equivalent pressure ratios

摘要

We report the performance of 1-eV GaNAsSb-based photovoltaic samples grown on a Si substrate using molecular beam epitaxy at different As/Ga beam equivalent pressure (BEP) ratios. The light current-voltage curve and spectral response of the samples were measured. The sample grown at an As/Ga BEP ratio of 10 showed the highest energy conversion efficiency with an open circuit voltage (V-OC) of 0.529V and a short circuit current density of 17.0mA/cm(2). This measured V-OC is the highest ever reported value in GaNAsSb 1-eV photovoltaic cell, resulting in the lowest ever reported E-g/q-V-OC of 0.50eV. The increase in the As/Ga BEP ratio also resulted in an increase in the bandgap-voltage offset value (E-g/q-V-OC) and a decrease in quantum efficiency up to As/Ga BEP ratio of 18. Copyright (c) 2015 John Wiley & Sons, Ltd.