High-barrier rectifying contacts on undoped ZnO films with (NH 4)2Sx treatment owing to Fermi-level pinning

Yow-Jon Lin, Shih Sheng Chang, Hsing Cheng Chang, Yang Chun Liu

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We report on the formation of high-barrier Ti and Ni contacts to (NH 4)2Sx-treated ZnO films grown by pulsed-laser deposition. The x-ray photoelectron spectroscopy (XPS) results show that the position of the Zn 3d core-level peak at the (NH4)2S x-treated ZnO surface is the same as that at the Ti/(NH 4)2Sx-treated ZnO or Ni/(NH4) 2Sx-treated ZnO interfaces, suggesting the occurrence of Fermi-level (EF) pinning and the formation of a barrier height of ∼2.7 eV. From the photoluminescence and XPS measurements, it is suggested that a high Zn-vacancy density might cause the ZnO EF to be pinned close to the Zn-vacancy defect level at approximately 0.7 eV above the valence band maximum. In addition, the discrepancy in barrier-height values obtained from XPS and current-voltage measurements suggests the formation of S-Zn surface dipoles with S atoms on the surfaces.

Original languageEnglish
Article number075308
JournalJournal of Physics D: Applied Physics
Volume42
Issue number7
DOIs
Publication statusPublished - 2009 Apr 9

Fingerprint

Photoelectron spectroscopy
Fermi level
x ray spectroscopy
photoelectron spectroscopy
X rays
Vacancies
Core levels
Voltage measurement
Electric current measurement
Pulsed laser deposition
Valence bands
electrical measurement
pulsed laser deposition
electric contacts
Photoluminescence
occurrences
dipoles
valence
photoluminescence
Atoms

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Cite this

@article{1ad7fa53489d469d93756de74640b8ca,
title = "High-barrier rectifying contacts on undoped ZnO films with (NH 4)2Sx treatment owing to Fermi-level pinning",
abstract = "We report on the formation of high-barrier Ti and Ni contacts to (NH 4)2Sx-treated ZnO films grown by pulsed-laser deposition. The x-ray photoelectron spectroscopy (XPS) results show that the position of the Zn 3d core-level peak at the (NH4)2S x-treated ZnO surface is the same as that at the Ti/(NH 4)2Sx-treated ZnO or Ni/(NH4) 2Sx-treated ZnO interfaces, suggesting the occurrence of Fermi-level (EF) pinning and the formation of a barrier height of ∼2.7 eV. From the photoluminescence and XPS measurements, it is suggested that a high Zn-vacancy density might cause the ZnO EF to be pinned close to the Zn-vacancy defect level at approximately 0.7 eV above the valence band maximum. In addition, the discrepancy in barrier-height values obtained from XPS and current-voltage measurements suggests the formation of S-Zn surface dipoles with S atoms on the surfaces.",
author = "Yow-Jon Lin and Chang, {Shih Sheng} and Chang, {Hsing Cheng} and Liu, {Yang Chun}",
year = "2009",
month = "4",
day = "9",
doi = "10.1088/0022-3727/42/7/075308",
language = "English",
volume = "42",
journal = "Journal Physics D: Applied Physics",
issn = "0022-3727",
publisher = "IOP Publishing Ltd.",
number = "7",

}

High-barrier rectifying contacts on undoped ZnO films with (NH 4)2Sx treatment owing to Fermi-level pinning. / Lin, Yow-Jon; Chang, Shih Sheng; Chang, Hsing Cheng; Liu, Yang Chun.

In: Journal of Physics D: Applied Physics, Vol. 42, No. 7, 075308, 09.04.2009.

Research output: Contribution to journalArticle

TY - JOUR

T1 - High-barrier rectifying contacts on undoped ZnO films with (NH 4)2Sx treatment owing to Fermi-level pinning

AU - Lin, Yow-Jon

AU - Chang, Shih Sheng

AU - Chang, Hsing Cheng

AU - Liu, Yang Chun

PY - 2009/4/9

Y1 - 2009/4/9

N2 - We report on the formation of high-barrier Ti and Ni contacts to (NH 4)2Sx-treated ZnO films grown by pulsed-laser deposition. The x-ray photoelectron spectroscopy (XPS) results show that the position of the Zn 3d core-level peak at the (NH4)2S x-treated ZnO surface is the same as that at the Ti/(NH 4)2Sx-treated ZnO or Ni/(NH4) 2Sx-treated ZnO interfaces, suggesting the occurrence of Fermi-level (EF) pinning and the formation of a barrier height of ∼2.7 eV. From the photoluminescence and XPS measurements, it is suggested that a high Zn-vacancy density might cause the ZnO EF to be pinned close to the Zn-vacancy defect level at approximately 0.7 eV above the valence band maximum. In addition, the discrepancy in barrier-height values obtained from XPS and current-voltage measurements suggests the formation of S-Zn surface dipoles with S atoms on the surfaces.

AB - We report on the formation of high-barrier Ti and Ni contacts to (NH 4)2Sx-treated ZnO films grown by pulsed-laser deposition. The x-ray photoelectron spectroscopy (XPS) results show that the position of the Zn 3d core-level peak at the (NH4)2S x-treated ZnO surface is the same as that at the Ti/(NH 4)2Sx-treated ZnO or Ni/(NH4) 2Sx-treated ZnO interfaces, suggesting the occurrence of Fermi-level (EF) pinning and the formation of a barrier height of ∼2.7 eV. From the photoluminescence and XPS measurements, it is suggested that a high Zn-vacancy density might cause the ZnO EF to be pinned close to the Zn-vacancy defect level at approximately 0.7 eV above the valence band maximum. In addition, the discrepancy in barrier-height values obtained from XPS and current-voltage measurements suggests the formation of S-Zn surface dipoles with S atoms on the surfaces.

UR - http://www.scopus.com/inward/record.url?scp=63749123493&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=63749123493&partnerID=8YFLogxK

U2 - 10.1088/0022-3727/42/7/075308

DO - 10.1088/0022-3727/42/7/075308

M3 - Article

AN - SCOPUS:63749123493

VL - 42

JO - Journal Physics D: Applied Physics

JF - Journal Physics D: Applied Physics

SN - 0022-3727

IS - 7

M1 - 075308

ER -