Improving the output power of near-ultraviolet InGaN/GaN-based light emitting diodes by enhancing the thermal and electrical properties of Ag-based reflector

Jae Seong Park, Jaecheon Han, Jae Woong Han, Heonjin Seo, Jung Tak Oh, Tae Yeon Seong

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We report on the improved performance of near-ultraviolet (385 nm) InGaN/GaN multi-quantum well light emitting diodes (LEDs) by enhancing the thermal and electrical properties of Ag-based reflector. It is shown that after annealing at 500 °C, indium (In)-overlaid Ag contact exhibits considerably higher reflectivity at 385 nm than Ag only contact. After annealing at 500°C, both the Ag only and In-overlaid Ag contacts are ohmic with a specific contact resistance of 6.7 × 10-4 and 8.7 × 10-5 Ω cm2, respectively. Near-UV (385 nm) LEDs fabricated with annealed Ag only and In-overlaid Ag reflectors show a forward-bias voltage of 3.4 and 3.37 V at an injection current of 20 mA, respectively. The LEDs with the annealed In-overlaid Ag reflector exhibit 24.7% higher light output power (at 20 mA) than the LEDs with the 500°C-annealed Ag only reflector. X-ray photoemission spectroscopy was performed to understand the improved electrical properties of the In-overlaid Ag reflectors. The enhanced thermal stability of In-overlaid Ag reflector is also briefly described.

Original languageEnglish
Pages (from-to)7-14
Number of pages8
JournalSuperlattices and Microstructures
Volume64
DOIs
Publication statusPublished - 2013 Oct 14

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Keywords

  • Ag ohmic reflector
  • In overlayer
  • Near-ultraviolet light-emitting diode
  • Thermal stability

ASJC Scopus subject areas

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

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