Structural, Optical, and Electrical Characterization of 643 nm Red InGaN Multiquantum Wells Grown on Strain‐Relaxed InGaN Templates

Red-emitting (approximate to 643 nm) InGaN multiquantum well active device layers and micro-LEDs are grown by metal organic chemical vapor deposition (MOCVD) on relaxed InGaN templates, the latter created via thermal decomposition of an InGaN underlayer, and examined via power- and temperature-dependent photoluminescence and electrical measurements. Maximum internal quantum efficiencies are determined to be 7.5% at an excitation power density of 13 W cm(-2), radiative recombination occurs through monomolecular recombination, and the fabricated micro-LEDs do not show any efficiency degradation with decreasing size. Peak on-wafer external quantum efficiency (EQE) of a 5 x 5 mu m(2) device is 0.44%, demonstrating that thermally decomposed InGaN "strain-relaxing" underlayers may be useful for long wavelength micro-LED applications.