Issue 1, 2019

13 mW operation of a 295–310 nm AlGaN UV-B LED with a p-AlGaN transparent contact layer for real world applications

Abstract

Smart, high-power ultraviolet (UV)-B light-emitting diode (LED) light sources are demanded for both medical and agricultural applications, including vitamin D3 production in human skin (294–304 nm), immunotherapy (310 nm), cancer therapy (295–310 nm) and enriching phytochemicals in plants (310 nm). To achieve this, we have combined graded stacks of AlGaN buffer layer (BL), AlGaN multi quantum wells (MQWs) with high internal quantum efficiency (IQE), a transparent p-AlGaN contact layer, and a highly-reflective p-type electrode for the fabrication of a UV-B LED. By optimizing the growth conditions, we demonstrated an output power of 7.1 mW for a 310 nm UV-B LED under bare-wafer conditions using a highly reflective Ni/Mg p-electrode. We also demonstrated a high IQE of 47% for UV-B emission from UV-B LED at 295 nm, by using a graded n-AlGaN BL. The light-extraction efficiency (LEE) was increased by introducing both a highly-transparent p-AlGaN and a highly reflective Ni/Mg p-electrode. As a result, we achieved an EQE of 4.4% at a dc drive current of 20 mA under CW-operation at RT and a maximum output power of 13 mW for a 295 nm UV-B LED for medical applications.

Graphical abstract: 13 mW operation of a 295–310 nm AlGaN UV-B LED with a p-AlGaN transparent contact layer for real world applications

Supplementary files

Article information

Article type
Paper
Submitted
01 ágú. 2018
Accepted
22 nóv. 2018
First published
22 nóv. 2018
This article is Open Access
Creative Commons BY-NC license

J. Mater. Chem. C, 2019,7, 143-152

13 mW operation of a 295–310 nm AlGaN UV-B LED with a p-AlGaN transparent contact layer for real world applications

M. A. Khan, N. Maeda, M. Jo, Y. Akamatsu, R. Tanabe, Y. Yamada and H. Hirayama, J. Mater. Chem. C, 2019, 7, 143 DOI: 10.1039/C8TC03825B

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements