Green electroluminescence using n-In2O3 nanorods formed on plasma surface treated p-GaN structure

Abstract

We demonstrate the green light-emitting diodes (LEDs) using n-In2O3 nanorods (NRs)/p-GaN based pn junction with an insertion of thin Ga2O3 layer. In order to form the oxide interfacial layer between nand p-material, O-2 plasma treatment was conducted on p-GaN surface. The X-ray photoelectron spectroscopy patterns clearly show the formation of thin Ga2O3 layer on p-GaN surface via O-2 plasma treatment. After formation of Ga2O3 layer on p-GaN surface, water droplet contact angle is decreased from 55 degrees to 39 degrees, which means that the surface is converted toward to more hydrophilic properties. The In(OH)(3) NRs with 300 nm-length and 150 nm-diameter are uniformly grown on plasma treated p-GaN surface by using hydrothermal method. After then, final In(2)O3 NRs were obtained by phase change from as-grown In(OH)(3) NRs without the morphology change by calcination process. The electroluminescence of fabricated LEDs using n-In2O3/Ga2O3/p-GaN heterojunction shows the green emission (lambda similar to 554 nm) at forward bias condition. As a possible light emission mechanism from our suggested heterostructures, the various defects energy states mediated green emissions were considered with band diagram.