Enhanced efficiency of GaN-based light-emitting diodes with periodic textured Ga-doped ZnO transparent contact layer

Jinn Kong Sheu*, Y. S. Lu, Min Lum Lee, W. C. Lai, Cheng-Huang Kuo, Chun Ju Tun

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

88 Scopus citations

Abstract

GaN-based light-emitting diodes (LEDs) with indium tin oxide (ITO)/Ga-doped ZnO (GZO) composite oxide films serving as a transparent contact layer (TCL) were demonstrated. In this study, the wall-plug efficiency of LEDs (LED-III) with textured ITO/GZO composite TCL can be markedly improved by 200% and 45% of magnitude as compared to conventional LEDs with NiAu TCL(LED-II) and planar ITO/GZO TCL(LED-I), respectively. Compared to LED-II, this enhancement is due to the enhanced light extraction efficiency of ITO/GZO composite TCL with high transparency. Compared to LED-I, ZnO-based TCL with a higher refractive index (n∼2.0) allows further enhancement of light extraction through the creation of a textured structure on transparent conductive oxide TCL deposited on the top surface of LEDs. In addition, the ITO/GZO composite TCL with a thickness of 550 nm is far larger than that of NiAu TCL with a thickness of approximately 15 nm. Therefore, in addition to the effect of high transparency, the thicker ITO/GZO TCL with low lateral resistance would also act as a current-spreading layer leading to an enhancement of light extraction.

Original languageEnglish
Article number263511
JournalApplied Physics Letters
Volume90
Issue number26
DOIs
StatePublished - 2 Aug 2007

Fingerprint Dive into the research topics of 'Enhanced efficiency of GaN-based light-emitting diodes with periodic textured Ga-doped ZnO transparent contact layer'. Together they form a unique fingerprint.

Cite this