Al2O3/AlN/Al-based backside diffuse reflector for high-brightness 370-nm AlGaN ultraviolet light-emitting diodes

Tae Hoon Park, Tae Ho Lee, Tae Geun Kim

Research output: Contribution to journalArticle

Abstract

We report an Al2O3/AlN/Al-based backside diffuse reflector for near-ultraviolet light-emitting diodes (NUV LEDs), and its superiority compared with conventional reflectors. After fabrication of LEDs, a sapphire (Al2O3) surface was UV-irradiated to utilize the diffuse reflection effect by roughening the surface. Then, a thermally treated AlN layer was deposited on it, to obtain a mirror-like surface, before deposition of Al. The reflectance increased by 1.3% and 3.9% for these Al2O3/AlN/Al reflectors without and with surface treatment, respectively, compared with an Al reflector. These reflectors were then used with 370 nm AlGaN NUV LEDs, and the performances of LEDs without and with an Al reflector were compared. As a result, the NUV LED with both thermally and UV-treated AlN/Al reflector exhibited the best performance, and its output power and electroluminescence intensity were higher by 82.7% and 41.9%, respectively, than those of the LED without a reflector.

LanguageEnglish
Pages1009-1015
Number of pages7
JournalJournal of Alloys and Compounds
Volume776
DOIs
Publication statusPublished - 2019 Mar 5

Fingerprint

Light emitting diodes
Luminance
Aluminum Oxide
Electroluminescence
Sapphire
Surface treatment
Ultraviolet Rays
aluminum gallium nitride
Mirrors
Fabrication

Keywords

  • Backside reflector
  • Light-emitting diodes
  • Surface treatment
  • Ultraviolet

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

Al2O3/AlN/Al-based backside diffuse reflector for high-brightness 370-nm AlGaN ultraviolet light-emitting diodes. / Park, Tae Hoon; Lee, Tae Ho; Kim, Tae Geun.

In: Journal of Alloys and Compounds, Vol. 776, 05.03.2019, p. 1009-1015.

Research output: Contribution to journalArticle

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abstract = "We report an Al2O3/AlN/Al-based backside diffuse reflector for near-ultraviolet light-emitting diodes (NUV LEDs), and its superiority compared with conventional reflectors. After fabrication of LEDs, a sapphire (Al2O3) surface was UV-irradiated to utilize the diffuse reflection effect by roughening the surface. Then, a thermally treated AlN layer was deposited on it, to obtain a mirror-like surface, before deposition of Al. The reflectance increased by 1.3{\%} and 3.9{\%} for these Al2O3/AlN/Al reflectors without and with surface treatment, respectively, compared with an Al reflector. These reflectors were then used with 370 nm AlGaN NUV LEDs, and the performances of LEDs without and with an Al reflector were compared. As a result, the NUV LED with both thermally and UV-treated AlN/Al reflector exhibited the best performance, and its output power and electroluminescence intensity were higher by 82.7{\%} and 41.9{\%}, respectively, than those of the LED without a reflector.",
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