Semipolar $({\hbox {20}}\bar{{\hbox {2}}}\bar{{\hbox {1}}})$ InGaN/GaN Light-Emitting Diodes for High-Efficiency Solid-State Lighting

This work examines the effects of polarization-related electric fields on the energy band diagrams, wavelength shift, wave function overlap, and efficiency droop for InGaN quantum wells on various crystal orientations, including polar (0001) (c -plane), semipolar (202̅1̅), semipolar (202̅1̅), and nonpolar (101̅0̅) (m-plane). Based on simulations, we show that the semipolar (202̅1̅) orientation exhibits excellent potential for the development of high-efficiency, low-droop light-emitting diodes (LEDs). We then present recent advancements in crystal growth, optical performance, and thermal performance of semipolar (202̅1̅) LEDs. Finally, we demonstrate a low-droop, high-efficiency single-quantum-well blue semipolar (202̅1̅) LED with an external quantum efficiency of more than 50% at 100 A/cm².