InGaN/AlGaInN-based ultraviolet light-emitting diodes with indium gallium tin oxide electrodes

Abstract

In this study, In-and Sn-doped GaO (IGTO) is proposed as an alternative transparent conductive electrode for indiwum tin oxide (ITO) to improve the performance of InGaN/AlGaInN-based near ultraviolet light-emitting diodes (NUV LEDs). IGTO films were prepared by co-sputtering the ITO and Ga2O3 targets under various target power ratios. Among those, IGTO films post-annealed at 700 degrees C under a hydrogen environment gave rise to a transmittance of 94% at 385 nm and a contact resistance of 9.4 x 10-3 Omega-cm2 with a sheet resistance of 124 Omega/Upsilon. Compared to ITO-based NUV LEDs, the IGTO-based NUV LED showed a 9% improvement in the light output power, probably due to IGTO's higher transmittance, although the forward voltage was still higher by 0.23 V. (C) 2015 Elsevier B.V. All rights reserved.