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^*

^*Corresponding author for this work

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

Bibliographical note

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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

Cite this

@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 = "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)",

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

number = "8",

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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

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

UR - https://www.scopus.com/pages/publications/85104419355

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

Bibliographical note

Keywords

ASJC Scopus subject areas

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