Highly Efficient Deep-UV Light-Emitting Diodes Using AIN-Based Deep-UV-Transparent Glass Electrodes

Abstract

Many studies have set out to develop electrodes that are both highly conductive and transparent across a wide spectral region, from visible to deep UV (DUV). However, few solutions have been proposed because.these two properties are mutually exclusive. In this paper, an AlN-based glass electrode film with a conducting filament formed by the application of an ac pulse is proposed as a solution, which exhibits a high transmittance in the DUV region (over 95.6% at 280 nm) and a low contact resistance with a P-Al0.4Ga0.6N layer (rho(c) = 3.2 X 10(-2) Omega.cm(2)). The Ohmic conduction mechanism at the interface between the AIN film and the p-Al0.4Ga0.6N layers is fully examined using various analytical tools. This AIN film is finally applied to a 280 nm top-emitting light-emitting diode, to verify the validity of the method, which exhibits very stable operations with a forward voltage of 7.7 V at 20 mA, a light output power of 7.49 mW at 100 mA, and, most importantly, a record high external quantum efficiency of 2.8% after packaging.