Green LEDs with V-defects formed from intentional dislocation half-loops

Group III-nitride light emitting diodes (LEDs) suffer from poor efficiency for longer wavelength emission. This is partly due to increased polarization-induced barriers to vertical carrier injection at InGaN/GaN interfaces in the polar c-plane, where higher In-content is required for long-wavelength emission. Polarization-induced barriers can be bypassed by lateral carrier injection through the semipolar sidewalls of V-defects, which form at the apex of threading dislocations (TDs) during kinetically limited growth. This increases wall-plug efficiency (WPE) through the reduction of forward voltage (VF). TD and resulting V-defect density can be controlled through the formation of edge dislocation half-loops prior to V-defect opening. In this work, we demonstrate a green V-defect LED with optimized AlGaN caps with high external quantum efficiency (EQE) and WPE. The green V-defect LED demonstrated here with such a device structure achieves a peak EQE and a peak WPE of 43.9% and 37.0%, respectively.