Polarization mechanism and Shockley Read Hall recombination on Quantum Efficiency of InGaN/GaN Blue LED

Abstract

Abstract InxGa1-x N/GaN blue LEDs faces significant efficiency droop issue. The causes of efficiency droop are Shockley Read Hall recombination (SRH), Auger recombination (AR), carrier delocalization (CD) and electron leakage (EL). The SRH, Auger and electron leakage are functions of carrier concentration and temperature. InGaN/GaN superlattice has polarization electric field at interface. In this work we explore effect of built in polarization (BIP) on efficiency droop. It is shown that polarization field enhances SRH coefficient resulting in more droop in internal quantum efficiency of blue LED. Thus, for improvement in efficiency, polarization field required to be minimized which requires growth of the material in m-plane instead of c-plane.