Indium Gallium Oxide Emitters for High-Efficiency CdTe-Based Solar Cells
Manoj K. Jamarkattel, Adam B. Phillips, Indra Subedi, Abasi Abudulimu, Ebin Bastola, Deng-Bing Li, Xavier Mathew, Yanfa Yan, Randy J. Ellingson, Nikolas J. Podraza, Michael J. Heben
Abstract
There are limited choices for front-surface, electron-selective contacts (emitters) for CdTe solar cells, thus hindering scientific and technical development. Here we investigate the photovoltaic performance of devices fabricated with (InxGa1–x)2O3 (IGO) emitters with varying In-to-Ga ratios prepared by cosputtering. In agreement with predictions, an IGO emitter with a 4.03 eV bandgap (x = 0.36) allowed fabrication of devices with efficiencies of 16%. Increasing the performance to higher values will be enabled by increasing the transmission through the IGO-coated substrate and decreasing the bulk and back interface recombination. These findings demonstrate IGO materials as effective emitters in high-efficiency CdTe-based solar cells.