Increased light extraction from vertical GaN light-emitting diodes with ordered, cone-shaped deep-pillar nanostructures

Ho Myoung An, Jae In Sim, Ki Seob Shin, Yun Mo Sung, Tae Geun Kim

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

In this paper, improved light extraction using cone-shaped deep-pillar nanostructures is demonstrated on the Honeycomb-type vertical GaN light-emitting diodes (VLEDs). In order to produce ordered, cone-shaped deep-pillar patterns on the surface of an n-type GaN, double-layered polystyrene (PS) nanospheres of 500-nm size were coated onto the n-GaN layer by a simple spin-coating. Then, immediately after the O 2 plasma ashing for double-layered PS beads, the Ni metal was deposited and lifted off to form a hard mask for deep pillar etching. Then, the three VLEDsthe reference VLED with no patterns and the two VLEDs with ordered, cone-shaped pillar patterns of 1.0 and 1.5 μ m depth on the n-type GaN surfacewere prepared for comparison. As a result, the output power for the proposed VLEDs with 1.0-and 1.5-μ m-deep cone-shaped patterns has been increased by 200% and 214%, respectively, at 350 mA as compared to the reference VLED. There was a slight sacrifice of operational voltage and leakage current. The improved optical properties are attributed to the multiple scattering of light from the sidewall of the cone-shaped patterns and the increased surface dimension.

Original languageEnglish
Article number6183454
Pages (from-to)891-896
Number of pages6
JournalIEEE Journal of Quantum Electronics
Volume48
Issue number7
DOIs
Publication statusPublished - 2012 May 22

Fingerprint

Light emitting diodes
Cones
Nanostructures
cones
light emitting diodes
Polystyrenes
polystyrene
Nanospheres
Multiple scattering
Spin coating
Leakage currents
beads
coating
Masks
Etching
leakage
masks
Optical properties
etching
Plasmas

Keywords

  • Cone-shaped
  • Double layer coating
  • Gallium nitride
  • Honeycomb-type
  • Nanosphere lithography
  • Vertical light emitting diode

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics

Cite this

Increased light extraction from vertical GaN light-emitting diodes with ordered, cone-shaped deep-pillar nanostructures. / An, Ho Myoung; Sim, Jae In; Shin, Ki Seob; Sung, Yun Mo; Kim, Tae Geun.

In: IEEE Journal of Quantum Electronics, Vol. 48, No. 7, 6183454, 22.05.2012, p. 891-896.

Research output: Contribution to journalArticle

@article{08b99482f74b41e587e6152fdcbe2bf7,
title = "Increased light extraction from vertical GaN light-emitting diodes with ordered, cone-shaped deep-pillar nanostructures",
abstract = "In this paper, improved light extraction using cone-shaped deep-pillar nanostructures is demonstrated on the Honeycomb-type vertical GaN light-emitting diodes (VLEDs). In order to produce ordered, cone-shaped deep-pillar patterns on the surface of an n-type GaN, double-layered polystyrene (PS) nanospheres of 500-nm size were coated onto the n-GaN layer by a simple spin-coating. Then, immediately after the O 2 plasma ashing for double-layered PS beads, the Ni metal was deposited and lifted off to form a hard mask for deep pillar etching. Then, the three VLEDsthe reference VLED with no patterns and the two VLEDs with ordered, cone-shaped pillar patterns of 1.0 and 1.5 μ m depth on the n-type GaN surfacewere prepared for comparison. As a result, the output power for the proposed VLEDs with 1.0-and 1.5-μ m-deep cone-shaped patterns has been increased by 200{\%} and 214{\%}, respectively, at 350 mA as compared to the reference VLED. There was a slight sacrifice of operational voltage and leakage current. The improved optical properties are attributed to the multiple scattering of light from the sidewall of the cone-shaped patterns and the increased surface dimension.",
keywords = "Cone-shaped, Double layer coating, Gallium nitride, Honeycomb-type, Nanosphere lithography, Vertical light emitting diode",
author = "An, {Ho Myoung} and Sim, {Jae In} and Shin, {Ki Seob} and Sung, {Yun Mo} and Kim, {Tae Geun}",
year = "2012",
month = "5",
day = "22",
doi = "10.1109/JQE.2012.2190587",
language = "English",
volume = "48",
pages = "891--896",
journal = "IEEE Journal of Quantum Electronics",
issn = "0018-9197",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "7",

}

TY - JOUR

T1 - Increased light extraction from vertical GaN light-emitting diodes with ordered, cone-shaped deep-pillar nanostructures

AU - An, Ho Myoung

AU - Sim, Jae In

AU - Shin, Ki Seob

AU - Sung, Yun Mo

AU - Kim, Tae Geun

PY - 2012/5/22

Y1 - 2012/5/22

N2 - In this paper, improved light extraction using cone-shaped deep-pillar nanostructures is demonstrated on the Honeycomb-type vertical GaN light-emitting diodes (VLEDs). In order to produce ordered, cone-shaped deep-pillar patterns on the surface of an n-type GaN, double-layered polystyrene (PS) nanospheres of 500-nm size were coated onto the n-GaN layer by a simple spin-coating. Then, immediately after the O 2 plasma ashing for double-layered PS beads, the Ni metal was deposited and lifted off to form a hard mask for deep pillar etching. Then, the three VLEDsthe reference VLED with no patterns and the two VLEDs with ordered, cone-shaped pillar patterns of 1.0 and 1.5 μ m depth on the n-type GaN surfacewere prepared for comparison. As a result, the output power for the proposed VLEDs with 1.0-and 1.5-μ m-deep cone-shaped patterns has been increased by 200% and 214%, respectively, at 350 mA as compared to the reference VLED. There was a slight sacrifice of operational voltage and leakage current. The improved optical properties are attributed to the multiple scattering of light from the sidewall of the cone-shaped patterns and the increased surface dimension.

AB - In this paper, improved light extraction using cone-shaped deep-pillar nanostructures is demonstrated on the Honeycomb-type vertical GaN light-emitting diodes (VLEDs). In order to produce ordered, cone-shaped deep-pillar patterns on the surface of an n-type GaN, double-layered polystyrene (PS) nanospheres of 500-nm size were coated onto the n-GaN layer by a simple spin-coating. Then, immediately after the O 2 plasma ashing for double-layered PS beads, the Ni metal was deposited and lifted off to form a hard mask for deep pillar etching. Then, the three VLEDsthe reference VLED with no patterns and the two VLEDs with ordered, cone-shaped pillar patterns of 1.0 and 1.5 μ m depth on the n-type GaN surfacewere prepared for comparison. As a result, the output power for the proposed VLEDs with 1.0-and 1.5-μ m-deep cone-shaped patterns has been increased by 200% and 214%, respectively, at 350 mA as compared to the reference VLED. There was a slight sacrifice of operational voltage and leakage current. The improved optical properties are attributed to the multiple scattering of light from the sidewall of the cone-shaped patterns and the increased surface dimension.

KW - Cone-shaped

KW - Double layer coating

KW - Gallium nitride

KW - Honeycomb-type

KW - Nanosphere lithography

KW - Vertical light emitting diode

UR - http://www.scopus.com/inward/record.url?scp=84861147717&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861147717&partnerID=8YFLogxK

U2 - 10.1109/JQE.2012.2190587

DO - 10.1109/JQE.2012.2190587

M3 - Article

AN - SCOPUS:84861147717

VL - 48

SP - 891

EP - 896

JO - IEEE Journal of Quantum Electronics

JF - IEEE Journal of Quantum Electronics

SN - 0018-9197

IS - 7

M1 - 6183454

ER -