Morphological stability of Ag reflector for high-power GaN-based vertical light-emitting diode by addition of Ni layer

Young Yun Choi, Tae Yeon Seong

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We investigated the reasons why Ag reflectors in vertical light-emitting diodes showed much better morphological stability with the addition of an intermediate Ni layer by means of X-ray pole figures, scanning electron microscopy (SEM), and SEM electron backscatter diffraction (EBSD) techniques. The SEM results showed that, unlike the pitted Ag-only contacts, the Ni-combined Ag contacts annealed at 300 °C contained only hillocks, even after annealing for 60 min. The EBSD results demonstrated that the Ag-only samples were more strongly 〈1 1 1〉-textured than the Ni-combined Ag samples after annealing for 60 min. The pole-figure results also indicated that, for both the samples, the {1 1 1} texture was enhanced by annealing, although the Ag-only samples were more highly 〈1 1 1〉-textured than the Ni-combined Ag samples. On the basis of the SEM, EBSD, and pole-figure results, we interpret and discuss the possible mechanisms underlying the improved morphological stability of the Ni-combined Ag reflectors.

Original languageEnglish
Pages (from-to)342-349
Number of pages8
JournalSuperlattices and Microstructures
Volume73
DOIs
Publication statusPublished - 2014 Jan 1

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reflectors
Light emitting diodes
light emitting diodes
Electron diffraction
Poles
Scanning electron microscopy
Annealing
scanning electron microscopy
poles
annealing
diffraction
electrons
Textures
X rays
textures
x rays

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Materials Science(all)

Cite this

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title = "Morphological stability of Ag reflector for high-power GaN-based vertical light-emitting diode by addition of Ni layer",
abstract = "We investigated the reasons why Ag reflectors in vertical light-emitting diodes showed much better morphological stability with the addition of an intermediate Ni layer by means of X-ray pole figures, scanning electron microscopy (SEM), and SEM electron backscatter diffraction (EBSD) techniques. The SEM results showed that, unlike the pitted Ag-only contacts, the Ni-combined Ag contacts annealed at 300 °C contained only hillocks, even after annealing for 60 min. The EBSD results demonstrated that the Ag-only samples were more strongly 〈1 1 1〉-textured than the Ni-combined Ag samples after annealing for 60 min. The pole-figure results also indicated that, for both the samples, the {1 1 1} texture was enhanced by annealing, although the Ag-only samples were more highly 〈1 1 1〉-textured than the Ni-combined Ag samples. On the basis of the SEM, EBSD, and pole-figure results, we interpret and discuss the possible mechanisms underlying the improved morphological stability of the Ni-combined Ag reflectors.",
keywords = "Ag reflector, Electron backscatter diffraction, LED, X-ray pole figure",
author = "Choi, {Young Yun} and Seong, {Tae Yeon}",
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AU - Seong, Tae Yeon

PY - 2014/1/1

Y1 - 2014/1/1

N2 - We investigated the reasons why Ag reflectors in vertical light-emitting diodes showed much better morphological stability with the addition of an intermediate Ni layer by means of X-ray pole figures, scanning electron microscopy (SEM), and SEM electron backscatter diffraction (EBSD) techniques. The SEM results showed that, unlike the pitted Ag-only contacts, the Ni-combined Ag contacts annealed at 300 °C contained only hillocks, even after annealing for 60 min. The EBSD results demonstrated that the Ag-only samples were more strongly 〈1 1 1〉-textured than the Ni-combined Ag samples after annealing for 60 min. The pole-figure results also indicated that, for both the samples, the {1 1 1} texture was enhanced by annealing, although the Ag-only samples were more highly 〈1 1 1〉-textured than the Ni-combined Ag samples. On the basis of the SEM, EBSD, and pole-figure results, we interpret and discuss the possible mechanisms underlying the improved morphological stability of the Ni-combined Ag reflectors.

AB - We investigated the reasons why Ag reflectors in vertical light-emitting diodes showed much better morphological stability with the addition of an intermediate Ni layer by means of X-ray pole figures, scanning electron microscopy (SEM), and SEM electron backscatter diffraction (EBSD) techniques. The SEM results showed that, unlike the pitted Ag-only contacts, the Ni-combined Ag contacts annealed at 300 °C contained only hillocks, even after annealing for 60 min. The EBSD results demonstrated that the Ag-only samples were more strongly 〈1 1 1〉-textured than the Ni-combined Ag samples after annealing for 60 min. The pole-figure results also indicated that, for both the samples, the {1 1 1} texture was enhanced by annealing, although the Ag-only samples were more highly 〈1 1 1〉-textured than the Ni-combined Ag samples. On the basis of the SEM, EBSD, and pole-figure results, we interpret and discuss the possible mechanisms underlying the improved morphological stability of the Ni-combined Ag reflectors.

KW - Ag reflector

KW - Electron backscatter diffraction

KW - LED

KW - X-ray pole figure

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