High quantum efficiency InGaN/GaN multiple quantum well solar cells with spectral response extending out to 520 nm

We demonstrate high quantum efficiency InGaN/GaN multiple quantum well (QW) solar cells with spectral response extending out to 520 nm. Increasing the number of QWs in the active region did not reduce the carrier collection efficiency for devices with 10, 20, and 30 QWs. Solar cells with 30 QWs and an intentionally roughened p-GaN surface exhibited a peak external quantum efficiency (EQE) of 70.9% at 390 nm, an EQE of 39.0% at 450 nm, an open circuit voltage of 1.93 V, and a short circuit current density of 2.53 mA/cm(2) under 1.2 suns AM1.5G equivalent illumination. (C) 2011 American Institute of Physics. [doi:10.1063/1.3591976]