Thermally stable and reflective RhZn/Ag ohmic contacts to p-type GaN for near-UV flip-chip light-emitting diodes

Seong Han Park, Joon Woo Jeon, Tae Yeon Seong, Jeong Tak Oh

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We investigated Rh-Zn solid solution (3 nm)/Ag(200 nm) schemes in order to produce thermally stable and low-resistance p-type Ohmic reflectors for high-performance flip-chip light-emitting diodes (LEDs). The Rh-Zn solid solution/Ag contacts show a specific contact resistance of 1.2 × 10-4 Ωcm2 and a reflectance of about 78% at a wavelength of 395 nm when annealed at 500 °C for 1 min in air. Scanning electron microscopy results show that unlike Ag only contacts, the Rh-Zn solid solution/Ag contacts experience insignificant morphological degradation even after annealing at 500 °C for 1 min. Near-UV InGaN/GaN LEDs (1200 × 600 μm2 in chip size) fabricated with the annealed Rh-Zn solid solution/Ag reflectors give a forward-bias voltage of 3.43 V at an injection current of 80 mA, which is lower than that (3.65 V) of LEDs with Ag only reflectors. LEDs with the annealed RhZn solid solution/Ag reflectors exhibit 43% higher light output power (at 80 mA) than the LEDs with annealed Ag contacts. X-ray photoemission spectroscopy examinations were performed to investigate possible Ohmic formation behaviors.

Original languageEnglish
Pages (from-to)156-160
Number of pages5
JournalJournal of the Korean Physical Society
Volume59
Issue number1
DOIs
Publication statusPublished - 2011 Jul 1

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Keywords

  • Ag
  • Light-emitting diode
  • Ohmic reflector
  • Rhodium-zinc solid solution

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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