Deep-ultraviolet light-emitting diodes with external quantum efficiency higher than 20% at 275 nm achieved by improving light-extraction efficiency

Enhancing the light-extraction efficiency is the key issue for realizing highly efficient AlGaN-based ultraviolet light-emitting diodes (UV-LEDs). We introduced several features to improve the light extraction: a transparent AlGaN:Mg contact layer, a Rh mirror electrode, an AlN template on a pattern...

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Published inApplied physics express Vol. 10; no. 3; pp. 31002 - 31005
Main Authors Takano, Takayoshi, Mino, Takuya, Sakai, Jun, Noguchi, Norimichi, Tsubaki, Kenji, Hirayama, Hideki
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.03.2017
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Summary:Enhancing the light-extraction efficiency is the key issue for realizing highly efficient AlGaN-based ultraviolet light-emitting diodes (UV-LEDs). We introduced several features to improve the light extraction: a transparent AlGaN:Mg contact layer, a Rh mirror electrode, an AlN template on a patterned sapphire substrate, and encapsulation resin. The combination of the AlGaN:Mg contact layer and the Rh mirror electrode significantly improved the output power and the external quantum efficiency (EQE) of UV-LEDs. By introducing the aforementioned features, a maximum EQE of >20% at an emission wavelength of 275 nm and a 20-mA direct current was achieved.
ISSN:1882-0778
1882-0786
DOI:10.7567/APEX.10.031002