Concentrating properties of nitride-based solar cells using GaInN/GaInN superlattices

We investigated the concentrating properties of nitride based solar cells at light intensities of up to 200 suns at room temperature. The devices were GaInN-based solar cells with a GaInN/GaInN superlattice active layer on a freestanding GaN substrate. The conversion efficiency of these solar cells increased with increasing of concentration up to 200 suns. We obtained the solar cells with a pit-free structure and up to 3.4% conversion efficiency by irradiating concentrated sunlight with intensities of up to 200 suns. The short-circuit current density, open-circuit voltage, fill factor, and conversion efficiency were 510 mA/cm 2 , 1.9 V, 70%, and 3.4%, respectively, under an air mass 1.5G at 200 suns and room temperature. We also discuss the relationship between crystal quality and solar cell performance.