Enhanced external efficiency of InGaN/GaN quantum well light-emitting diodes by mediating surface plasmon-polaritons

Abstract

An effect of mediation of surface plasmon-polaritons in the spontaneous radiation process of InGaN/GaN quantum-well light-emitting diodes is studied as a method for increasing the external efficiency. A finite-difference time-domain (FDTD) simulation is used to calculate the efficiency of extraction from surface plasmon-polaritons to out-side radiation. We found that a reflection type diffraction grating was more desirable than a transmission type. After optimization of the grating geometries and consideration of the Purcell enhancement factor, a 1.4-fold increase in the external efficiency is estimated when the thickness of the positively-doped GaN between the silver anode and the quantum well is 20 nm.