Low-resistance nonalloyed ohmic contacts on undoped ZnO films grown by pulsed-laser deposition

Chia Lung Tsai, Yow-Jon Lin, Yi Min Chin, W. R. Liu, W. F. Hsieh, C. H. Hsu, Jian An Chu

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

We report on the formation of nonalloyed Ti and Ni ohmic contacts to ZnO films grown by pulsed-laser deposition. The experimental results show a lower barrier height of the Ti/ZnO samples than that of the Ni/ZnO samples (due to the lower work function of Ti than Ni), suggesting the Fermi-level unpinning at the interfaces. Based on the thermionic-emission or the thermionic-field-emission model, we found weak barrier-height dependence of the contact resistivity, implying that the presence of hydroxide in ZnO (i.e. the formation of the narrow depletion region at the metal/ZnO interface) resulted in the excess current component related to tunnelling, which led to the formation of the low-resistance nonalloyed metal/ZnO contact. The measurement temperature dependence of the contact resistivity revealed that the dominant current transport mechanism is field emission.

Original languageEnglish
Article number095108
JournalJournal of Physics D: Applied Physics
Volume42
Issue number9
DOIs
Publication statusPublished - 2009 May 7

Fingerprint

Thermionic emission
Ohmic contacts
low resistance
Pulsed laser deposition
Field emission
pulsed laser deposition
electric contacts
Metals
thermionic emission
field emission
Fermi level
Temperature measurement
electrical resistivity
metals
hydroxides
depletion
temperature dependence
titanium nickelide
hydroxide ion

All Science Journal Classification (ASJC) codes

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

Cite this

Tsai, Chia Lung ; Lin, Yow-Jon ; Chin, Yi Min ; Liu, W. R. ; Hsieh, W. F. ; Hsu, C. H. ; Chu, Jian An. / Low-resistance nonalloyed ohmic contacts on undoped ZnO films grown by pulsed-laser deposition. In: Journal of Physics D: Applied Physics. 2009 ; Vol. 42, No. 9.
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Low-resistance nonalloyed ohmic contacts on undoped ZnO films grown by pulsed-laser deposition. / Tsai, Chia Lung; Lin, Yow-Jon; Chin, Yi Min; Liu, W. R.; Hsieh, W. F.; Hsu, C. H.; Chu, Jian An.

In: Journal of Physics D: Applied Physics, Vol. 42, No. 9, 095108, 07.05.2009.

Research output: Contribution to journalArticle

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AU - Tsai, Chia Lung

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