Blue, Green, and Amber InGaN/GaN Light-Emitting Diodes on Semipolar 11-22 GaN Bulk Substrates

We demonstrate the fabrication of blue, green, and amber InGaN/GaN light-emitting diodes (LEDs) on semipolar 11-22 bulk GaN substrates. The 11-22GaN substrates used in this study are produced by cutting out from a c-oriented GaN bulk crystal grown by hydride vapor epitaxy. The LEDs have a dimension of 320 ×320 µm2 and are packed in an epoxide resin. The output power and external quantum efficiency (EQE) at a driving current of 20 mA are 1. 76 mW and 3. 0%, respectively, for the blue LED, 1. 91 mW and 4. 1% for the green LED, and 0. 54 mW and 1. 3% for the amber LED. The maximum output powers obtained with a maximum current of 200 mA are 19. 0 mW (blue), 13. 4 mW (green), and 1. 9 mW (amber), while the maximum EQEs are 4. 0% at 140 mA (blue), 4. 9% at 0. 2 mA (green), and 1. 6% at 1 mA (amber). It is confirmed that the emission light is polarized along the 1-100 direction, reflecting the low crystal symmetry of the 11-22 plane.