The impact of different ZnO growth methods on the electrical and optical properties of a n-ZnO/p-GaN:Mg/c-plane sapphire UV LED

Abstract

ZnO films were successfully grown on GaN/sapphire by Pulsed Laser Deposition (PLD) and the sol–gel technique. The purpose was to study the effect of each method on the properties of a n-ZnO/p-GaN/sapphire UV LED device. The PLD grown ZnO films were obtained at 20 Pa and 30 Pa ambient oxygen pressure while the sol–gel grown ZnO films were evaluated as annealed films and as deposited films. It was found that the device performance is strongly dependent on the ZnO layer deposition method. The present work demonstrates the ability of both chemical and physical growth methods (sol–gel and PLD, respectively) to develop high quality ZnO nanofilms with tailored optical properties by selecting the growth conditions. The obtained results show the importance of further studies on the heterojunction ZnO/GaN as a UV LED promising a wide range of applications.