Enhancement of InGaN-Based Vertical LED With Concavely Patterned Surface Using Patterned Sapphire Substrate

Author

Lee, Jae-Hoon ; Oh, Jeong-Tak ; Choi, Seok-Boem ; Kim, Yong-Chun ; Cho, Hyun-Ick ; Lee, Jung-Hee

Author_Institution

Samsung Electro-Mech. Co. Ltd., Suwon

Volume

20

Issue

5

fYear

2008

fDate

3/1/2008 12:00:00 AM

Firstpage

345

Lastpage

347

Abstract

To improve the external quantum efficiency, we have proposed a new method utilizing surface roughening of vertical-type light-emitting diodes (VT-LEDs) fabricated on hemispherical patterned sapphire substrate by using a laser lift-off technique. The advantages of this method are simple and reproducible in transferring the well-defined patterns on sapphire into GaN layer. The VT-LED with concavely patterned surface showed a nearly twofold increase in the output power compared to the normal planar surface. This improvement in the VT-LED performances is attributed to the increase in the escaping probability of photons from the LED surface.

Keywords

III-V semiconductors; gallium compounds; indium compounds; light emitting diodes; surface roughness; Al₂O₃; InGaN; InGaN-based LED; concavely patterned surface; external quantum efficiency; laser lift-off technique; light-emitting diodes; patterned sapphire substrate; photon escaping probability; surface roughening; vertical LED; Etching; Gallium nitride; Light emitting diodes; Liquid crystal displays; Plasma applications; Power generation; Rough surfaces; Surface roughness; Surface texture; Vertical cavity surface emitting lasers; GaN; laser lift-off (LLO); patterned sapphire; surface texture; vertical light-emitting diode (LED);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2007.915648

Filename

4447287