Simulation investigation of dual-wavelength tuning of light emitting diodes with single QW structure

Abstract

In the present study, spectral tuning of dual-wavelength emission in monolithic InGaN/GaN multiple-quantum well light-emitting diodes was investigated based on an experiment. The reference InGaN/GaN QWs are composed of GaN barriers and “three layers” wells containing a “wetting layer”, a grading layer and a relatively low indium content InGaN layer, which has been grown in the laboratory. The simulation results show that the short wavelength light-emitting peak rises with the increasing of the grading layer thickness. In the meantime, when the thickness of the low indium content InGaN layer decreases, the long wavelength light-emitting peak falls. Dual-wavelength emissions can be achieved by tuning the grading layer thickness and the low indium content InGaN layer thickness. In addition, as the ratios of grading layer to the low indium content InGaN layer increase, the emission peaks show redshift because the interband transitions energy became smaller.