Improving emission uniformity of ingan/gan-based vertical leds by using reflective ito/ag n-contact

Woong Sun Yum; Ji Hyun Koo; Dae Hee Lee; Young Hoon Kim; Young Kyu Jeong; Se Yeon Jung; Sang Youl Lee; Hwan Hee Jeong; Tae Yeon Seong

doi:10.3390/electronics10080975

Improving emission uniformity of ingan/gan-based vertical leds by using reflective ito/ag n-contact

Woong Sun Yum, Ji Hyun Koo, Dae Hee Lee, Young Hoon Kim, Young Kyu Jeong, Se Yeon Jung, Sang Youl Lee, Hwan Hee Jeong, Tae Yeon Seong

Department of Materials Science and Engineering

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

1 Citation (Scopus)

Abstract

We investigated the effect of Ti/Al and ITO/Ag n-type contacts on the emission uniformity and light output of different chip-size vertical-geometry light-emitting diodes (VLEDs) for vehicle headlamp application. The forward voltage of the Ti/Al-based reference VLEDs decreased from 3.38 to 3.20 V at 1500 mA with increasing chip size from (1280 × 1000 µm²) to (1700 × 1700 µm²), whereas that of the ITO/Ag-based samples changed from 3.37 to 3.15 V. Regardless of chip size, the ITO/Ag-based samples revealed higher light output power than the reference samples. For example, the ITO/Ag-based samples (chip size of 1700 × 1700 µm²) exhibited 3.4% higher light output power at 1500 mA than the reference samples. The ITO/Ag samples underwent less degradation in the Wall-plug efficiency (WPE) than the reference sample. For instance, the ITO/Ag-based samples (1700 × 1700 µm²) gave 4.8% higher WPE at 1500 mA than the reference samples. The ITO/Ag-based samples illustrated more uniform emission than the Ti/Al-based sample. Both the reference and ITO/Ag-based samples underwent no degradation when operated at 1500 mA for 1000 h.

Original language	English
Article number	975
Journal	Electronics (Switzerland)
Volume	10
Issue number	8
DOIs	https://doi.org/10.3390/electronics10080975
Publication status	Published - 2021 Apr 2

Keywords

ITO/Ag
InGaN
Light emitting diode
Ohmic contact
Reflector
Vertical geometry

ASJC Scopus subject areas

Control and Systems Engineering
Signal Processing
Hardware and Architecture
Computer Networks and Communications
Electrical and Electronic Engineering

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10.3390/electronics10080975

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@article{a10261f3b2b04f15b3c64b66c03219fa,

title = "Improving emission uniformity of ingan/gan-based vertical leds by using reflective ito/ag n-contact",

abstract = "We investigated the effect of Ti/Al and ITO/Ag n-type contacts on the emission uniformity and light output of different chip-size vertical-geometry light-emitting diodes (VLEDs) for vehicle headlamp application. The forward voltage of the Ti/Al-based reference VLEDs decreased from 3.38 to 3.20 V at 1500 mA with increasing chip size from (1280 × 1000 µm2) to (1700 × 1700 µm2), whereas that of the ITO/Ag-based samples changed from 3.37 to 3.15 V. Regardless of chip size, the ITO/Ag-based samples revealed higher light output power than the reference samples. For example, the ITO/Ag-based samples (chip size of 1700 × 1700 µm2) exhibited 3.4% higher light output power at 1500 mA than the reference samples. The ITO/Ag samples underwent less degradation in the Wall-plug efficiency (WPE) than the reference sample. For instance, the ITO/Ag-based samples (1700 × 1700 µm2) gave 4.8% higher WPE at 1500 mA than the reference samples. The ITO/Ag-based samples illustrated more uniform emission than the Ti/Al-based sample. Both the reference and ITO/Ag-based samples underwent no degradation when operated at 1500 mA for 1000 h.",

keywords = "ITO/Ag, InGaN, Light emitting diode, Ohmic contact, Reflector, Vertical geometry",

author = "Yum, {Woong Sun} and Koo, {Ji Hyun} and Lee, {Dae Hee} and Kim, {Young Hoon} and Jeong, {Young Kyu} and Jung, {Se Yeon} and Lee, {Sang Youl} and Jeong, {Hwan Hee} and Seong, {Tae Yeon}",

note = "Funding Information: Funding: This work was supported by the Global Research Laboratory (GRL) program through the National Research Foundation (NRF) of Korea (NRF-2017K1A1A2013160) and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration. Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland.",

year = "2021",

month = apr,

day = "2",

doi = "10.3390/electronics10080975",

language = "English",

volume = "10",

journal = "Electronics (Switzerland)",

issn = "2079-9292",

publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",

number = "8",

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TY - JOUR

T1 - Improving emission uniformity of ingan/gan-based vertical leds by using reflective ito/ag n-contact

AU - Yum, Woong Sun

AU - Koo, Ji Hyun

AU - Lee, Dae Hee

AU - Kim, Young Hoon

AU - Jeong, Young Kyu

AU - Jung, Se Yeon

AU - Lee, Sang Youl

AU - Jeong, Hwan Hee

AU - Seong, Tae Yeon

N1 - Funding Information: Funding: This work was supported by the Global Research Laboratory (GRL) program through the National Research Foundation (NRF) of Korea (NRF-2017K1A1A2013160) and the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/4/2

Y1 - 2021/4/2

N2 - We investigated the effect of Ti/Al and ITO/Ag n-type contacts on the emission uniformity and light output of different chip-size vertical-geometry light-emitting diodes (VLEDs) for vehicle headlamp application. The forward voltage of the Ti/Al-based reference VLEDs decreased from 3.38 to 3.20 V at 1500 mA with increasing chip size from (1280 × 1000 µm2) to (1700 × 1700 µm2), whereas that of the ITO/Ag-based samples changed from 3.37 to 3.15 V. Regardless of chip size, the ITO/Ag-based samples revealed higher light output power than the reference samples. For example, the ITO/Ag-based samples (chip size of 1700 × 1700 µm2) exhibited 3.4% higher light output power at 1500 mA than the reference samples. The ITO/Ag samples underwent less degradation in the Wall-plug efficiency (WPE) than the reference sample. For instance, the ITO/Ag-based samples (1700 × 1700 µm2) gave 4.8% higher WPE at 1500 mA than the reference samples. The ITO/Ag-based samples illustrated more uniform emission than the Ti/Al-based sample. Both the reference and ITO/Ag-based samples underwent no degradation when operated at 1500 mA for 1000 h.

AB - We investigated the effect of Ti/Al and ITO/Ag n-type contacts on the emission uniformity and light output of different chip-size vertical-geometry light-emitting diodes (VLEDs) for vehicle headlamp application. The forward voltage of the Ti/Al-based reference VLEDs decreased from 3.38 to 3.20 V at 1500 mA with increasing chip size from (1280 × 1000 µm2) to (1700 × 1700 µm2), whereas that of the ITO/Ag-based samples changed from 3.37 to 3.15 V. Regardless of chip size, the ITO/Ag-based samples revealed higher light output power than the reference samples. For example, the ITO/Ag-based samples (chip size of 1700 × 1700 µm2) exhibited 3.4% higher light output power at 1500 mA than the reference samples. The ITO/Ag samples underwent less degradation in the Wall-plug efficiency (WPE) than the reference sample. For instance, the ITO/Ag-based samples (1700 × 1700 µm2) gave 4.8% higher WPE at 1500 mA than the reference samples. The ITO/Ag-based samples illustrated more uniform emission than the Ti/Al-based sample. Both the reference and ITO/Ag-based samples underwent no degradation when operated at 1500 mA for 1000 h.

KW - ITO/Ag

KW - InGaN

KW - Light emitting diode

KW - Ohmic contact

KW - Reflector

KW - Vertical geometry

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U2 - 10.3390/electronics10080975

DO - 10.3390/electronics10080975

M3 - Article

AN - SCOPUS:85104419355

SN - 2079-9292

VL - 10

JO - Electronics (Switzerland)

JF - Electronics (Switzerland)

IS - 8

M1 - 975

ER -

Improving emission uniformity of ingan/gan-based vertical leds by using reflective ito/ag n-contact

Abstract

Keywords

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