Theoretical simulation of Hybrid II-O/III-N green light-emitting diode with MgZnO/InGaN/MgZnO heterojunction

Abstract

We propose a hybrid light-emitting diode (LED) design comprising of p-MgZnO/InGaN/n-MgZnO sandwiched structure and emanating green electroluminescence centered at 560 nm. Different design strategies for optimizing the internal quantum efficiency (IQE) through 2-D numerical simulation have been proposed. Moreover, the feasibility of device realization is also reviewed. Detailed study of the effects of alloy composition, dopant concentration, and thickness of the electron blocking layer (EBL) and hole blocking layer (HBL) on the IQE is carried out. The optimization in selecting materials for EBL, HBL, and active layer is addressed while maximizing device IQE and reducing the efficiency droop. The impact of Auger non-radiative recombination on luminous power and quantum efficiency is discussed. The mechanisms behind efficiency droop, namely Auger recombination and electron leakage are elaborated. It is found that the hybrid LED shows the highest IQE of 93% with minimum efficiency droop as compared to ZnO based and GaN based LEDs for similar design parameters. ©2014 Elsevier Ltd. All rights reserved.