Improved performance of deep ultraviolet AlGaN-based light-emitting diode by reducing contact resistance of Al-based reflector

Kee Baek Sim; Jun Young Jin; Su Kyung Kim; Young Jin Ko; Gyu Weon Hwang; Tae Yeon Seong; Hiroshi Amano

doi:10.1016/j.jallcom.2022.164895

Improved performance of deep ultraviolet AlGaN-based light-emitting diode by reducing contact resistance of Al-based reflector

Kee Baek Sim, Jun Young Jin, Su Kyung Kim, Young Jin Ko, Gyu Weon Hwang, Tae Yeon Seong, Hiroshi Amano

Research output: Contribution to journal › Article › peer-review

5 Citations (Scopus)

Abstract

In this study, chlorine (Cl) treatment was carried out on p-AlGaN to enhance the performance of ultraviolet-C light emitting diodes (UVC LEDs) by modifying ITO work function and hence reducing the contact resistance of ITO/Al reflector. The Cl-treated UVC LEDs exhibit the forward voltage of 6.88 V at 20 mA, whereas the reference samples show 7.50 V. The light output power and relative wall plug efficiency (WPE) of the Cl-treated UVC LEDs are enhanced by 17.1% at 500 mW and 19.5% at 100 mA, respectively, as compared to the reference. Additionally, the Cl-treated LEDs also display reduction in both the leakage current and ideality factor. Further, the photoluminescence (PL) intensity of AlGaN micro-disks is also enhanced by the Cl-treatment. X-ray photoemission spectroscopy (XPS) results indicate the formation of Cl-ITO at the ITO/p-AlGaN interface and the passivation of the surface states of AlGaN by Cl radicals. Based on the XPS results, a possible mechanism for the improved performance of Cl-treated UVC AlGaN-based LEDs is described and discussed.

Original language	English
Article number	164895
Journal	Journal of Alloys and Compounds
Volume	910
DOIs	https://doi.org/10.1016/j.jallcom.2022.164895
Publication status	Published - 2022 Jul 25

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSICT) ( NRF-2017K1A1A2013160 and NRF-2022R1A2C2006887 ), the KIST Institution Program (No. 2E31040 ), and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration .

Publisher Copyright:
© 2022 Elsevier B.V.

Keywords

Chlorine treatment
ITO
Surface passivation
UVC LEDs
Work function

ASJC Scopus subject areas

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.jallcom.2022.164895

Cite this

@article{9cf64dd183084c33b0e94c80d4844675,

title = "Improved performance of deep ultraviolet AlGaN-based light-emitting diode by reducing contact resistance of Al-based reflector",

abstract = "In this study, chlorine (Cl) treatment was carried out on p-AlGaN to enhance the performance of ultraviolet-C light emitting diodes (UVC LEDs) by modifying ITO work function and hence reducing the contact resistance of ITO/Al reflector. The Cl-treated UVC LEDs exhibit the forward voltage of 6.88 V at 20 mA, whereas the reference samples show 7.50 V. The light output power and relative wall plug efficiency (WPE) of the Cl-treated UVC LEDs are enhanced by 17.1% at 500 mW and 19.5% at 100 mA, respectively, as compared to the reference. Additionally, the Cl-treated LEDs also display reduction in both the leakage current and ideality factor. Further, the photoluminescence (PL) intensity of AlGaN micro-disks is also enhanced by the Cl-treatment. X-ray photoemission spectroscopy (XPS) results indicate the formation of Cl-ITO at the ITO/p-AlGaN interface and the passivation of the surface states of AlGaN by Cl radicals. Based on the XPS results, a possible mechanism for the improved performance of Cl-treated UVC AlGaN-based LEDs is described and discussed.",

keywords = "Chlorine treatment, ITO, Surface passivation, UVC LEDs, Work function",

author = "Sim, {Kee Baek} and Jin, {Jun Young} and Kim, {Su Kyung} and Ko, {Young Jin} and Hwang, {Gyu Weon} and Seong, {Tae Yeon} and Hiroshi Amano",

note = "Funding Information: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSICT) ( NRF-2017K1A1A2013160 and NRF-2022R1A2C2006887 ), the KIST Institution Program (No. 2E31040 ), and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration . Publisher Copyright: {\textcopyright} 2022 Elsevier B.V.",

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doi = "10.1016/j.jallcom.2022.164895",

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T1 - Improved performance of deep ultraviolet AlGaN-based light-emitting diode by reducing contact resistance of Al-based reflector

AU - Sim, Kee Baek

AU - Jin, Jun Young

AU - Kim, Su Kyung

AU - Ko, Young Jin

AU - Hwang, Gyu Weon

AU - Seong, Tae Yeon

AU - Amano, Hiroshi

N1 - Funding Information: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSICT) ( NRF-2017K1A1A2013160 and NRF-2022R1A2C2006887 ), the KIST Institution Program (No. 2E31040 ), and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration . Publisher Copyright: © 2022 Elsevier B.V.

PY - 2022/7/25

Y1 - 2022/7/25

N2 - In this study, chlorine (Cl) treatment was carried out on p-AlGaN to enhance the performance of ultraviolet-C light emitting diodes (UVC LEDs) by modifying ITO work function and hence reducing the contact resistance of ITO/Al reflector. The Cl-treated UVC LEDs exhibit the forward voltage of 6.88 V at 20 mA, whereas the reference samples show 7.50 V. The light output power and relative wall plug efficiency (WPE) of the Cl-treated UVC LEDs are enhanced by 17.1% at 500 mW and 19.5% at 100 mA, respectively, as compared to the reference. Additionally, the Cl-treated LEDs also display reduction in both the leakage current and ideality factor. Further, the photoluminescence (PL) intensity of AlGaN micro-disks is also enhanced by the Cl-treatment. X-ray photoemission spectroscopy (XPS) results indicate the formation of Cl-ITO at the ITO/p-AlGaN interface and the passivation of the surface states of AlGaN by Cl radicals. Based on the XPS results, a possible mechanism for the improved performance of Cl-treated UVC AlGaN-based LEDs is described and discussed.

AB - In this study, chlorine (Cl) treatment was carried out on p-AlGaN to enhance the performance of ultraviolet-C light emitting diodes (UVC LEDs) by modifying ITO work function and hence reducing the contact resistance of ITO/Al reflector. The Cl-treated UVC LEDs exhibit the forward voltage of 6.88 V at 20 mA, whereas the reference samples show 7.50 V. The light output power and relative wall plug efficiency (WPE) of the Cl-treated UVC LEDs are enhanced by 17.1% at 500 mW and 19.5% at 100 mA, respectively, as compared to the reference. Additionally, the Cl-treated LEDs also display reduction in both the leakage current and ideality factor. Further, the photoluminescence (PL) intensity of AlGaN micro-disks is also enhanced by the Cl-treatment. X-ray photoemission spectroscopy (XPS) results indicate the formation of Cl-ITO at the ITO/p-AlGaN interface and the passivation of the surface states of AlGaN by Cl radicals. Based on the XPS results, a possible mechanism for the improved performance of Cl-treated UVC AlGaN-based LEDs is described and discussed.

KW - Chlorine treatment

KW - ITO

KW - Surface passivation

KW - UVC LEDs

KW - Work function

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AN - SCOPUS:85128234266

SN - 0925-8388

VL - 910

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

M1 - 164895

ER -

Improved performance of deep ultraviolet AlGaN-based light-emitting diode by reducing contact resistance of Al-based reflector

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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