Perspectives on UVC LED: Its Progress and Application

Tsung-Chi Hsu; Yu-Tsai Teng; Yen-Wei Yeh; Xiaotong Fan; Kuo-Hsiung Chu; Su-Hui Lin; Kuo-Kuang Yeh; Po-Tsung Lee; Yue Lin; Zhong Chen; Tingzhu Wu; Hao-Chung Kuo

doi:10.3390/photonics8060196

Photonics (May 2021)

Perspectives on UVC LED: Its Progress and Application

Tsung-Chi Hsu,
Yu-Tsai Teng,
Yen-Wei Yeh,
Xiaotong Fan,
Kuo-Hsiung Chu,
Su-Hui Lin,
Kuo-Kuang Yeh,
Po-Tsung Lee,
Yue Lin,
Zhong Chen,
Tingzhu Wu,
Hao-Chung Kuo

Affiliations

Tsung-Chi Hsu: Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
Yu-Tsai Teng: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Yen-Wei Yeh: Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
Xiaotong Fan: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Kuo-Hsiung Chu: Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
Su-Hui Lin: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Kuo-Kuang Yeh: Picosun China Co. Ltd., Suzhou 215000, China
Po-Tsung Lee: Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
Yue Lin: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Zhong Chen: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Tingzhu Wu: Fujian Engineering Research Center for Solid-State Lighting, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China
Hao-Chung Kuo: Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan

DOI: https://doi.org/10.3390/photonics8060196
Journal volume & issue: Vol. 8, no. 6
p. 196

Abstract

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High-quality epitaxial layers are directly related to internal quantum efficiency. The methods used to design such epitaxial layers are reviewed in this article. The ultraviolet C (UVC) light-emitting diode (LED) epitaxial layer structure exhibits electron leakage; therefore, many research groups have proposed the design of blocking layers and carrier transportation to generate high electron–hole recombination rates. This also aids in increasing the internal quantum efficiency. The cap layer, p-GaN, exhibits high absorption in deep UV radiation; thus, a small thickness is usually chosen. Flip chip design is more popular for such devices in the UV band, and the main factors for consideration are light extraction and heat transportation. However, the choice of encapsulation materials is important, because unsuitable encapsulation materials will be degraded by ultraviolet light irradiation. A suitable package design can account for light extraction and heat transportation. Finally, an atomic layer deposition Al2O3 film has been proposed as a mesa passivation layer. It can provide a low reverse current leakage. Moreover, it can help increase the quantum efficiency, enhance the moisture resistance, and improve reliability. UVC LED applications can be used in sterilization, water purification, air purification, and medical and military fields.

Published in Photonics

ISSN: 2304-6732 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Engineering (General). Civil engineering (General): Applied optics. Photonics
Website: http://www.mdpi.com/journal/photonics

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