Internal quantum efficiency of GaN/AlGaN‐based multi quantum wells on different dislocation densities underlying layers

Internal quantum efficiency (IQE) of GaN/AlGaN multi quantum wells on the low dislocation density Al0.25Ga0.75N grown by epitaxial lateral overgrowth (ELO) and facet controlled epitaxial lateral overgrowth were investigated by excitation intensity dependent photoluminescence measurement. The threading dislocation density decreased from 4x109cm-2 to 2x108cm-2 by using ELO method, then the IQE was much improved from 5% to 40% when the carrier density was 1x1018cm-3. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)