Abstract
The fabrication of ultra-high-resolution micro-displays with low power consumption is essential for applications in virtual reality and augmented reality systems. In this regard, GaN-based light-emitting diodes (LEDs) have been regarded as a promising candidate for self-emissive micro-displays. However, micro-LEDs suffer from sidewall defects and low quantum efficiency at a low current. Thus, we investigated the electrical and optical properties of InGaN-based green (520 nm) LEDs as functions of V pits and chip size. With decreasing chip size, the forward voltage of all samples increased at the same injection current. The samples with V pits exhibited markedly higher current density than those without V pits. With decreasing chip size, the current densities of all the samples increased, whereas the output power at the same current density decreased. As the chip size decreased, the peak external quantum efficiency of all the samples decreased, which was attained at high current densities. Furthermore, the samples with V pits displayed more efficient current spreading behavior, smaller ideality factors, and a smaller S parameter than the ones without V pits. The emission wavelength of the small samples (<300 μm) was blue-shifted with increasing current density. Based on the cathodoluminescence results, the effects of chip size, current density, and V pits on the electroluminescence spectral shift of green LEDs are described and discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 146-152 |
| Number of pages | 7 |
| Journal | Journal of Alloys and Compounds |
| Volume | 796 |
| DOIs | |
| Publication status | Published - 2019 Aug 5 |
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Keywords
- External quantum efficiency
- Micro-light-emitting diode
- Size dependence
- V pit
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry
Cite this
Combined effects of V pits and chip size on the electrical and optical properties of green InGaN-based light-emitting diodes. / Kim, Dae Hyun; Park, Young Soo; Kang, Daesung; Kim, Kyoung Kook; Seong, Tae Yeon; Amano, Hiroshi.
In: Journal of Alloys and Compounds, Vol. 796, 05.08.2019, p. 146-152.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Combined effects of V pits and chip size on the electrical and optical properties of green InGaN-based light-emitting diodes
AU - Kim, Dae Hyun
AU - Park, Young Soo
AU - Kang, Daesung
AU - Kim, Kyoung Kook
AU - Seong, Tae Yeon
AU - Amano, Hiroshi
PY - 2019/8/5
Y1 - 2019/8/5
N2 - The fabrication of ultra-high-resolution micro-displays with low power consumption is essential for applications in virtual reality and augmented reality systems. In this regard, GaN-based light-emitting diodes (LEDs) have been regarded as a promising candidate for self-emissive micro-displays. However, micro-LEDs suffer from sidewall defects and low quantum efficiency at a low current. Thus, we investigated the electrical and optical properties of InGaN-based green (520 nm) LEDs as functions of V pits and chip size. With decreasing chip size, the forward voltage of all samples increased at the same injection current. The samples with V pits exhibited markedly higher current density than those without V pits. With decreasing chip size, the current densities of all the samples increased, whereas the output power at the same current density decreased. As the chip size decreased, the peak external quantum efficiency of all the samples decreased, which was attained at high current densities. Furthermore, the samples with V pits displayed more efficient current spreading behavior, smaller ideality factors, and a smaller S parameter than the ones without V pits. The emission wavelength of the small samples (<300 μm) was blue-shifted with increasing current density. Based on the cathodoluminescence results, the effects of chip size, current density, and V pits on the electroluminescence spectral shift of green LEDs are described and discussed.
AB - The fabrication of ultra-high-resolution micro-displays with low power consumption is essential for applications in virtual reality and augmented reality systems. In this regard, GaN-based light-emitting diodes (LEDs) have been regarded as a promising candidate for self-emissive micro-displays. However, micro-LEDs suffer from sidewall defects and low quantum efficiency at a low current. Thus, we investigated the electrical and optical properties of InGaN-based green (520 nm) LEDs as functions of V pits and chip size. With decreasing chip size, the forward voltage of all samples increased at the same injection current. The samples with V pits exhibited markedly higher current density than those without V pits. With decreasing chip size, the current densities of all the samples increased, whereas the output power at the same current density decreased. As the chip size decreased, the peak external quantum efficiency of all the samples decreased, which was attained at high current densities. Furthermore, the samples with V pits displayed more efficient current spreading behavior, smaller ideality factors, and a smaller S parameter than the ones without V pits. The emission wavelength of the small samples (<300 μm) was blue-shifted with increasing current density. Based on the cathodoluminescence results, the effects of chip size, current density, and V pits on the electroluminescence spectral shift of green LEDs are described and discussed.
KW - External quantum efficiency
KW - Micro-light-emitting diode
KW - Size dependence
KW - V pit
UR - http://www.scopus.com/inward/record.url?scp=85065445604&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065445604&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2019.05.070
DO - 10.1016/j.jallcom.2019.05.070
M3 - Article
VL - 796
SP - 146
EP - 152
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -