Enhanced Light Output Power of GaN Light-Emitting Diodes with Graphene Film as a Transparent Conducting Electrode

We report the enhanced light output power of GaN-based light-emitting diode (LED) by using graphene film as a transparent conducting electrode. Monolayer graphene was synthesized on copper foil by using chemical vapor deposition method and directly transferred onto the GaN-LED as a top electrode. Compared to the conventional LEDs using indium tin oxide (ITO) layer for an electrode material, the light output power of LED with graphene electrode was improved by ~25%. This was attributed excellent graphene characteristics of high electrical conductivity, high optical transmittance of nearly 97% over a wide range of infrared, visible, and ultraviolet region and large area uniformity with fewer defects.