Theoretical analysis of Li-doped CdZnO-based high quantum efficiency multiple quantum-well green light emitting diode

Abstract

A comprehensive numerical analysis of Cd0.4Zn0.6O/ZnO multiple quantum well (MQW)/barrier green light emitting diode (LED) with high internal quantum efficiency (IQE) is presented. Room temperature electroluminescence (EL) from the MQW green LED is obtained 516 nm wavelength with a device IQE around 94%, while the LED has a turn-on voltage of 3.1 V. The effects of thickness, doping, and alloy composition of various device constituent layers are comprehensively studied while optimizing the concerned green LED performance at room temperature. Room temperature EL intensity is observed to experience a 1.25-fold enhancement by Li ion doping (Li-doping concentration is maintained at 1 × 1018 cm-3 ) of CdZnO well region, possibly due to the strain-induced piezoelectric polarization and spontaneous polarization reduction caused by Li ferroelectric dipole moment. Copyright © 2014 American Scientific Publishers