Tandem Structure for Efficiency Improvement in GaN Based Light-Emitting Diodes

Author

Miao-Chan Tsai ; Leung, Bosco ; Ta-Cheng Hsu ; Yen-Kuang Kuo

Author_Institution

Inst. of Photonics, Nat. Changhua Univ. of Educ., Changhua, Taiwan

Volume

32

Issue

9

fYear

2014

fDate

1-May-14

Firstpage

1801

Lastpage

1806

Abstract

The improvement in efficiency of nitride-based light-emitting diodes by the implementation of a vertically stacked tandem structure is investigated. The electrical and optical characteristics of an LED with a tunnel junction inserted between two active regions are modeled, and the wall-plug efficiency gain of the tandem LED is shown to start at 4.2% at low output powers (27.6 mW), with increasing efficiency gains with increased output power due to the alleviation of efficiency droop. The TLED concept further enables optimization of device structure, allowing removal of electron blocking layer, and optimization of number of quantum wells for improvement in efficiency.

Keywords

III-V semiconductors; gallium compounds; light emitting diodes; optimisation; semiconductor device models; semiconductor quantum wells; wide band gap semiconductors; GaN; TLED; device structure optimization; efficiency droop; efficiency improvement; electrical characteristics; electron blocking layer removal; light emitting diodes; optical characteristics; quantum wells; tunnel junction; vertically stacked tandem structure; wall-plug efficiency gain; Conductivity; Gallium nitride; Materials; Power generation; Radiative recombination; Superluminescent diodes; Light emitting diodes; semiconductor device modeling; wide band gap semiconductors;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2014.2313953

Filename

6780638