Paper Abstract and Keywords |
Presentation |
2017-12-15 14:10
[Invited Talk]
Recent progress of AlGaN deep-UV LEDs Hideki Hirayama, Masafumi Jo, Noritoshi Maeda (RIKEN), Yukio Kashima (Marubun) LQE2017-91 Link to ES Tech. Rep. Archives: LQE2017-91 |
Abstract |
(in Japanese) |
(See Japanese page) |
(in English) |
AlGaN deep ultraviolet light-emitting diodes (DUV-LEDs) are attracting a great deal of attention, since they have the potential to be used in a wide variety of applications, such as for sterilization, water purification, UV curing, and in the medical and biochemistry fields, and so on. As a result of recent developments in AlGaN DUV LEDs, high internal quantum efficiencies (IQE) of more than 60-70 % have been achieved by reducing the threading dislocation density (TDD) of the AlN, by improving the crystal growth technique and/or by the introduction of AlN single crystal wafers. However, the wall-plug efficiency (WPE) of AlGaN DUV-LEDs still remains at several percent. The first target for the efficiency of AlGaN DUV-LEDs is to go beyond an efficiency of 20%, which would make them comparable to mercury lamps. A significant problem is that the light-extraction efficiency (LEE) of AlGaN DUV-LEDs is still quite low because of heavy UV absorption through the p-GaN contact-layer. Clearly, improving the LEE is a major topic in the development of AlGaN DUV-LEDs. Transparent contact layers and highly reflective electrodes are considered to be necessary in order to obtain sufficiently high LEEs in DUV LEDs. In this work, we demonstrate a record EQE ever reported of over 20% in an AlGaN DUV-LED by using a transparent p-AlGaN contact layer and a highly reflective p-type electrode to improve the LEE. We also demonstrated a record WPE of 10.8% in a DUV LED by suppressing the applying voltage reducing the contact resistance of p-AlGaN/reflective electrode. |
Keyword |
(in Japanese) |
(See Japanese page) |
(in English) |
deep-UV LED / AlN / AlGaN / MOCVD / threading dislocation density / wall plug efficiency / / |
Reference Info. |
IEICE Tech. Rep., vol. 117, no. 358, LQE2017-91, pp. 21-26, Dec. 2017. |
Paper # |
LQE2017-91 |
Date of Issue |
2017-12-08 (LQE) |
ISSN |
Print edition: ISSN 0913-5685 Online edition: ISSN 2432-6380 |
Copyright and reproduction |
All rights are reserved and no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Notwithstanding, instructors are permitted to photocopy isolated articles for noncommercial classroom use without fee. (License No.: 10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) |
Download PDF |
LQE2017-91 Link to ES Tech. Rep. Archives: LQE2017-91 |
Conference Information |
Committee |
LQE |
Conference Date |
2017-12-15 - 2017-12-15 |
Place (in Japanese) |
(See Japanese page) |
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Paper Information |
Registration To |
LQE |
Conference Code |
2017-12-LQE |
Language |
English |
Title (in Japanese) |
(See Japanese page) |
Sub Title (in Japanese) |
(See Japanese page) |
Title (in English) |
Recent progress of AlGaN deep-UV LEDs |
Sub Title (in English) |
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Keyword(1) |
deep-UV LED |
Keyword(2) |
AlN |
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AlGaN |
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MOCVD |
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threading dislocation density |
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wall plug efficiency |
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1st Author's Name |
Hideki Hirayama |
1st Author's Affiliation |
RIKEN (RIKEN) |
2nd Author's Name |
Masafumi Jo |
2nd Author's Affiliation |
RIKEN (RIKEN) |
3rd Author's Name |
Noritoshi Maeda |
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RIKEN (RIKEN) |
4th Author's Name |
Yukio Kashima |
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Marubun (Marubun) |
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Speaker |
Author-2 |
Date Time |
2017-12-15 14:10:00 |
Presentation Time |
30 minutes |
Registration for |
LQE |
Paper # |
LQE2017-91 |
Volume (vol) |
vol.117 |
Number (no) |
no.358 |
Page |
pp.21-26 |
#Pages |
6 |
Date of Issue |
2017-12-08 (LQE) |
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