Improved performance of GaN-based blue light emitting diodes with InGaN/GaN multilayer barriers

Abstract

Multi-layer barrier structure is suggested as an alternative approach to single-layer polarization matching barrier structure for the reduction of efficiency droop. Time resolved photoluminescence measurement showed that polarization field was reduced by 19% in the multilayer barrier light emitting diodes structures. Optical power measurements on packaged devices showed overall increase of external quantum efficiency for all currents up to the current density of 150 A/cm(2). Increase of optical power is attributed to reduced polarization and decreased current overflow to p-side cladding layers. These results provide additional evidences that polarization is important in addressing the droop problem.