Enhancement of wall-plug efficiency in vertical InGaN/GaN LEDs by improved current spreading.

Opt Express

Department of Materials Science and Engineering, Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang, Gyeongbuk 790-874, South Korea.

Published: March 2012

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.

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http://dx.doi.org/10.1364/OE.20.00A287DOI Listing

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