The influence of material quality of lower InGaN waveguide layer on the performance of GaN-based laser diodes

Abstract We investigated the influence of surface morphology, V-defects and residual impurities of InGaN lower waveguide layer on the performance of GaN-based laser diodes. It is found that the surface roughness is one of key factors to affect the L-I and I-V characteristics of lasers. A smooth interface/surface is critical to reduce the threshold current and resistance of the laser. Reducing the V-defects and impurities in InGaN waveguide layer is also expected to raise current injection efficiency and reduce series resistance of lasers.