Observation of positive thermal power coefficient in InGaN/GaN quantum well solar cells

We report on the unique thermal properties of In 0.28 Ga 0.72 N/GaN multiple quantum well solar cells. The devices exhibited an external quantum efficiency of 69% (26%) at 390 nm (460 nm), an open circuit voltage of 2.04 V, a fill factor of 63%, a short circuit current density of 2 mA/cm 2 , and a peak output power of 2.63 mW/cm 2 at room temperature under 1-sun AM1.5G illumination. Thermal measurements showed that the peak output power increased with temperature up to 2.73 mW/cm 2 at 70°C, signifying the potential of III-nitride solar cells for concentrator photovoltaic applications.