Electrical and Optical Properties of a Transparent Conductive ITO/Ga2O3/Ag/Ga2O3 Multilayer for Ultraviolet Light-Emitting Diodes

Abstract

We fabricated an indium tin oxide (ITO)/Ga2O3/Ag/Ga2O3 multilayer as a transparent conductive electrode for ultraviolet light-emitting diodes (UV LEDs). The electrical and optical properties of the multilayer were improved by optimizing the annealing temperature of the ITO contact layer and the whole ITO/Ga2O3/Ag/Ga2O3 multilayer, and the thickness of the ITO contact layer and Ag metal layer. After optimization, the sheet resistance and transmittance of the ITO/Ga2O3/Ag/Ga2O3 multilayer was 3.43 Ω/sq and 86.4% at 335 nm, respectively. The ITO/Ga2O3/Ag/Ga2O3 multilayer also exhibited a good ohmic contact characteristic with a specific contact resistance of 1.45×10−3 Ω·cm2. These results show that the proposed ITO/Ga2O3/Ag/Ga2O3 multilayer is a promising alternative as a p-type electrode for UV LEDs.