High-Power, Low-Efficiency-Droop Semipolar ($20\bar{2}\bar{1}$) Single-Quantum-Well Blue Light-Emitting Diodes

Abstract

We demonstrate a small-area (0.1 mm2) semipolar (2021) blue (447 nm) light-emitting diode (LED) with high light output power (LOP) and external quantum efficiency (EQE) by utilizing a single 12-nm-thick InGaN quantum well. The LED had pulsed LOPs of 140, 253, 361, and 460 mW, and EQEs of 50.1, 45.3, 43.0, and 41.2%, at current densities of 100, 200, 300, and 400 A/cm2, respectively. The device showed little blue shift and had a narrow full width at half maximum (FWHM). Micro-electroluminescence (µ-EL) and scanning transmission electron microscope (STEM) images indicate a high-quality InGaN quantum well (QW) layer.