EBIC investigation of InGaN/GaN multiple quantum well structures irradiated with low energy electrons

Abstract

Light emitting structures with InGaN/GaN multiple quantum wells have been studied in the Electron Beam Induced Current (EBIC) mode of a scanning electron microscope (SEM). Special attention is paid to the channels of enhanced carrier transport across the active region demonstrating bright EBIC contrast. Defects with the smallest bright contrast are associated with threading dislocations while the large defects present in lower density could be associated with dislocation bunches. Low energy (10 keV) electron beam irradiation in the SEM was found to suppress the bright EBIC contrast of these defects. A comparison with the cathodoluminescence spectra changes due to similar exposure allows us to assume that recombination enhanced diffusion is responsible for the effects observed. © Published under licence by IOP Publishing Ltd 2011.