Strain relaxation of InGaN/GaN multi-quantum well light emitters via nanopatterning

inductively coupled plasma etch to produce nanorod structures. The InGaN/GaN MQW nanorods were characterized using X-ray diffraction (XRD) reciprocal space mapping to quantify the degree of relaxation. A peak relaxation of 32% was achieved for the smallest diameter features tested (120 nm after etching). Power-dependent photoluminescence at 13 K showed blue-shifted quantum well emission upon relaxation, which is attributed to reduction of the inherent piezoelectric field in the III-nitrides. Poisson-Schrödinger simulations of single well structures also predicted increasing spectral blueshift with strain relaxation, in agreement with experiments.