Optical and electrical improvements of semipolar (1 1 −2 2) GaN-based light emitting diodes by Si doping of n-GaN template

Abstract

We report that the performance of semipolar (11−22) GaN-based light-emitting diodes (LEDs) was improved by increasing the Si-doping concentration of n-type GaN templates. In-plane and out-of plane high-resolution X-ray diffraction demonstrated that crystal defects such as threading dislocation, partial stacking faults and basal stacking faults, were significantly decreased by increasing the Si-doping concentration. This resulted in the increase of carrier mobility due to reduction of the defect-scattering effect. Furthermore, the quality of InGaN/GaN quantum-well interfaces was improved by increasing the Si-doping concentration of the n-type GaN template. Based on these results, we suggest that the light-output power and operation voltage of semipolar (11−22) GaN-based LEDs would be improved by increasing Si doping concentration of n-type GaN templates.