Abstract
We present a study of the optical properties of a series of InGaN/GaN multiple quantum well structures, with room temperature peak emission wavelengths of 540 nm. By adopting a two-temperature growth method and designing structures to have short radiative lifetimes, we have obtained room temperature internal photoluminescence quantum efficiencies of 8%. Transmission electron microscopy images have revealed the presence of edge-type threading misfit dislocations in the multiple quantum well stack, which may be preventing the efficiency from reaching the very high values obtained in blue emitting InGaN/GaN multiple quantum well structures. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.