Semipolar (20\bar{2}1) Single-Quantum-Well Red Light-Emitting Diodes with a Low Forward Voltage

We have demonstrated the InGaN/GaN single-quantum-well (SQW) red light-emitting diodes (LEDs) grown on the free-standing GaN (20 (2) over bar1) substrate with a forward voltage as low as 2.8 V at 20 mA. A low p-GaN growth temperature is required to prevent the structure deterioration during the p-GaN growth. The reduction of the forward voltage was observed as the emission wavelength increased in the (20 (2) over bar1) SQW LEDs, which is attributed to its reversed polarization-related electric field compared to the conventional c-plane LEDs. (C) 2013 The Japan Society of Applied Physics