Low-resistance and transparent Ni-Co solid solution/Au ohmic contacts to p-type GaN for green GaN-based light-emitting diodes

Kang Won Kim, Hyun Gi Hong, June O. Song, Joon Ho Oh, Tae Yeon Seong

Research output: Contribution to journalArticle

3 Citations (Scopus)


We report on the formation of low-resistance and transparent p-type ohmic contact for green GaN-based light-emitting diodes (LEDs) using Ni-Co solid solution(5 nm)/Au(5 nm) scheme. The as-deposited Ni-Co solid solution(5 nm)/Au(5 nm) contact shows nonlinear current-voltage (I - V) characteristics. However, annealing the sample at 550 {ring operator}C in air results in the formation of ohmic contacts with specific contact resistance of 6.5×10-4 Ω cm2. The annealed sample shows light transmittance of 71.7% at a wavelength of 530 nm, which is better than that (64.9%) of oxidized Ni/Au contacts. Based on Auger electron spectroscopy and x-ray photoemission spectroscopy results, the annealing-induced improvement of the contacts is described and discussed.

Original languageEnglish
Pages (from-to)735-741
Number of pages7
JournalSuperlattices and Microstructures
Issue number6
Publication statusPublished - 2008 Dec 1



  • Contact resistivity
  • Green LED
  • Light transmittance
  • Ni-Co solid solution/Au
  • Ohmic contact

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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