Correlation between emission spectra and defect position in InGaN-based light emitting devices

Abstract

GaN/InGaN/AlGaN devices grown on sapphire and SiC substrates have a high defect density due to a large lattice mismatch between substrate and active structure. Different models exist why defects are ineffective as recombination centres so that it is possible to manufacture high brightness InGaN-based LED devices despite the high defect density. Using a scanning near field optical microscope (SNOM) we were able to look at the emission spectra of GaInN/GaN multiple quantum wells in the vicinity of defects and to see the change of emission wavelength and light intensity around defect positions. © 2002 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.