On the Carrier Transport for InGaN/GaN Core-Shell Nanorod Green Light-Emitting Diodes

In this paper, we model and investigate the carrier transport for the core-shell nanorod (NR) structured green light-emitting diodes (LEDs) for which the InGaN/GaN multiple quantum wells are grown on the nonpolar surface of the NR. Our results show the absence of polarization fields in the m-plane quantum wells for the core-shell NR LEDs, which manifest the flat energy band condition, the improved electron injection efficiency, and the high electron-hole wave functions overlap for the quantum wells, leading to the high radiative recombination rate and the enhanced quantum efficiency. We further find that the quantum efficiency is also affected by the vertical charge injection for the core-shell NR LEDs. The vertical charge injection is more sensitive to the doping concentration and the thickness of the p-GaN layer than of the n-GaN layer. Moreover, the increase of the NR height also leads to the nonuniform vertical charge injection.