Design and growth optimization by dual ion beam sputtered zno-based high-efficiency multiple quantum well green light emitting diode

Abstract

This manuscript deals with a theoretical design of Cd0-4Zn0-6O/ZnO multiple quantum well light emitting diode using commercial simulation software and experimentally optimized growth conditions of n-type ZnO on Si (001) substrate by dual ion beam sputtering deposition system. Theoretical study reveals an internal quantum efficiency 93.5% is achieved at room temperature from the device, emitting at 510 nm with a turn-on voltage of 3 V. The effect of substrate temperature on ZnO thin film has been investigated. Growth parameters optimization is performed using structural, electrical, optical and morphological characterizations. X-ray diffraction measurement show that the ZnO films grown at substrate temperatures of 200-C, 400-C and 600-C have a (002) preferred orientation. Four probe Hall measurements demonstrate achievements of a maximum carrier mobility of 26.53 cm2/V s with a low electrical resistivity of 0.062-cm and a carrier concentration of 38×1018 cm3 at room temperature for the film grown at 500-C. Photoluminescence studies conducted at room temperature describe a strong band-edge emission at 380 nm from ZnO samples. Prominent photoluminescence shoulder peaks are observed at -485 nm and 618 nm from ZnO film grown at 400-C Copyright © 2014 American Scientific Publishers All rights reserved.