High performance of GaN-based flip-chip light-emitting diodes with hole-shape patterned ITO ohmic contact layer and AgIn reflector

Sang Hern Lee; Jong Hyeob Baek; Tae Hoon Kim; Lee Soon Park

doi:10.1166/jnn.2011.3492

High performance of GaN-based flip-chip light-emitting diodes with hole-shape patterned ITO ohmic contact layer and AgIn reflector

J Nanosci Nanotechnol. 2011 Oct;11(10):8695-9. doi: 10.1166/jnn.2011.3492.

Authors

Sang Hern Lee¹, Jong Hyeob Baek, Tae Hoon Kim, Lee Soon Park

Affiliation

¹ Korea Photonics Technology Institute, Gwangju 500-460, Korea.

PMID: 22400245
DOI: 10.1166/jnn.2011.3492

Abstract

The enhancement of light extraction efficiency is observed when the hole-shape patterned ITO ohmic contact layer and AgIn reflector is adopted in GaN-based flip-chip (FC) light emitting diodes (LEDs). ITO layer (140 nm) and AgIn (200 nm) was deposited on the top of p-GaN by in-line DC sputtering and electron beam evaporating system, respectively. The ITO ohmic contact layer showed a low specific contact resistance of 2.66 x 10(-5) Omega cm(-2) and high transmittance of >85% at visible spectral regions. The AgIn reflector exhibited a low specific contact resistance of 1.90 x 10(-5) Omega cm(-2) and high reflectance of approximately 84% at visible spectral regions. Comparing with unpatterned ITO/AgIn layer, the optical output power of GaN-based FC LEDs improves approximately 30% by the adoption of micro size hole-shape patterned ITO ohmic contact layer and AgIn reflector.