Optical Properties of a NiO/Al-based Reflector for High-power Ultraviolet Light-emitting Diodes
Optical Properties of a NiO/Al-based Reflector for High-power Ultraviolet Light-emitting Diodes
- 주제(키워드) Ultraviolet light-emitting diodes , Reflector , Nickel oxide
- 발행기관 한국물리학회
- 발행년도 2011
- 총서유형 Journal
- UCI G704-000411.2011.58.42.008
- KCI ID ART001545367
- 본문언어 영어
초록/요약
We report the optical properties of a nickel oxide (NiO)/Al-based p-type reflector for verticaltype ultra-violet (UV) light-emitting diodes. The NiO film, a p-type transparent conductive oxide material, has been used as p-type Ohmic materials for wide bandgap materials; however, its optical properties have not yet been optimized for applications in the UV range. In this work, we first deposited a 10-nm-thick NiO films on AlGaN epilayers and then annealed them at temperature from 500 ℃ to 900 ℃ by using a rapid thermal process for 1 min ∼ 30 min to optimize the transmittance; then, the Al reflector with an optimized transmittance was deposited on indium-tinoxide films. Finally, we obtained an 84% transmittance from the NiO film and a 51% reflectance from the NiO/Al reflector at 365 nm after annealing at 800 ℃ for 20 min in an oxygen ambient.
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