Impact of post-growth thermal annealing on emission of InGaN/GaN multiple quantum wells

Abstract

Photoluminescence, photoluminescence excitation and time-resolved luminescence study of three In0.15Ga0.85N/GaN multiple quantum wells (MQWs) with well-widths of 2, 3, 4-nm, upon thermal annealing at 800°C for 30 min is presented. Blueshift of luminescence and pronounced changes in the absorbance indicate on remarkable interdiffusion of indium at the quantum well barrier interface for thin MQWs. While pronounced redshift in luminescence and increase in the excitation lifetime is attributed to prevalence of strain-induced field-effect for the thicker MQWs. Site-selective spectroscopy and microstructure analysis monitors improvement of the MQW interface quality of the thicker layers as well as reduction of disorder of in the quantum well layer upon post-growth thermal annealing. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.