title: Enhancement of wall-plug efficiency in vertical InGaN/GaN LEDs by improved current spreading.
abstract: We present the enhancement of wall-plug efficiency in vertical InGaN/GaN light-emitting diodes (V-LEDs) by improved current spreading with a novel Al2O3 current blocking layer (CBL). The Al2O3 CBL deposited by electron-beam evaporation shows high transmittance and good corrosion resistance to acidic solutions. V-LEDs with an Al2O3 CBL show similar light output power but lower forward voltage as compared to those with a SiO2 CBL deposited by plasma-enhanced chemical vapor deposition. As a result, the wall-plug efficiency of V-LEDs with an Al2O3 CBL at 500 mA was improved by 5% as compared to those with a SiO2 CBL, and by 19% as compared to those without a CBL.
authors.affiliation: Department of Materials Science and Engineering, Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-874, South Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Son
authors.forename: Buem Joon
authors.initials: BJ
authors.lastname: Kim
authors.forename: Chul Jong
authors.initials: CJ
authors.lastname: Ryu
authors.forename: Yang Hee
authors.initials: YH
authors.lastname: Song
authors.forename: Hwan Keon
authors.initials: HK
authors.lastname: Lee
authors.forename: Joo Won
authors.initials: JW
authors.lastname: Choi
authors.forename: Jong-Lam
authors.initials: JL
authors.lastname: Lee