Cathodoluminescence study of the excitons localization in AlGaN/GaN and InGaN/GaN quantum wells grown on sapphire
Al0.1Ga0.9N(5nm)/GaN(2nm) and In0.2Ga0.8N/GaN quantum wells (QWs) grown on GaN/sapphire have been studied by cathodoluminescence (CL) spectroscopy and imaged using an experimental setup especially developed for scanning near-field CL microscopy, which combines a scanning force microscope and a scanning electron microscope. The CL spectra show the characteristic band edge emission peak of GaN at lambda = 364 nm and the emission peaks related to the presence of QWs, at 41 = 353 and 430 nm for the AlGaN/GaN and the InGaN/GaN samples, respectively. Monochromatic CL images reveal that the emission of the AlGaN/GaN and InGaN/GaN QWs is localized at the level of the grains observed by SFM. A cross sectional analysis of the InGaN/GaN sample gives insight into its growth and an estimation of the exciton diffusion length of about L = 180 nm. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords: cathodoluminescence ; molecular beam epitaxy ; quantum wells ; gallium ; compounds ; semiconducting III-V materials ; MOLECULAR-BEAM EPITAXY ; WURTZITE GAN ; FIELD ; AMMONIA ; SURFACE ; ENERGY ; BLUE
Record created on 2010-10-05, modified on 2016-08-08