Enhanced opto-electrical properties of graphene electrode InGaN/GaN LEDs with a NiOx inter-layer

We report the fabrication of gallium nitride (GaN)-based light-emitting diode (LED) with uniform and monolayer graphene as transparent current spreading layer. Two-dimensional graphene successfully provides efficient current spreading and hole injection into the active layers of the LEDs for light emission. To further reduce the ohmic contact resistance between p-GaN and graphene film, ultrathin NiOx inter-layer is introduced in the device, improving its electrical and optical performance.