Highly transparent conductive Ag/Ga2O3 electrode for near-ultraviolet light-emitting diodes

Abstract

We fabricated an Ag/Ga2O3 bilayer as a highly transparent conductive electrode for near-ultraviolet (NUV) light-emitting diodes (LEDs). The bilayer showed nonohmic characteristics because the as-deposited Ga2O3 film is an insulator. However, the bilayer thermally annealed in ambient air and N-2 at 550 degrees C for 1 min showed ohmic-like current-voltage characteristics including specific contact resistances of 3.06 x 10(-2) and 7.34 x 10(-2) Omega cm(2), respectively. The optical transmittance and sheet resistance of the bilayer were about 91% and <42 Omega/square at 380 nm. The results suggest that the Ag/Ga2O3 bilayer is suitable for application as a p-type electrode in NUV-LEDs. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim