GaN-based light-emitting diodes with Ni/AuBe transparent conductive layer

Abstract

Ni/AuBe as p-type ohmic contact to p-GaN in the heat treatment process are reported. By selection of an optimum condition, the best construction of Ni/AuBe bi-layers is 5 nm/5 nm thick. The light-transmission is about 75% for 470 nm blue light and the lowest specific contact resistance obtained is 2 x 10(-3) Omega cm(2) examined by transmission line model after heat treatment process at 500 degreesC alloying temperature during 10 min in nitrogen ambient. The Be atom may plays an important role in the formation of good ohmic contacts. On the other hand, Ni/AuBe bi-layers are also applied to GaN-based light-emitting diodes (LEDs) as p-type ohmic contact electrode. The typical I-V characteristics of the GaN-based LEDs with 5 nm/5 nm-thick Ni/AuBe TCL exhibit a forward-bias voltage of 3.41 V at injection Current of 20 mA. (C) 2003 Elsevier Ltd. All rights reserved.