Carrier concentration dependence of the electrical behaviors of ITO contacts on n-type ZnO

Sang Ho Kim, Dea Kue Hwang, Seong Ju Park, Tae Yeon Seong

Research output: Contribution to journalArticle


We report on the carrier concentration dependence of the electrical characteristics of ITO Ohmic contacts to unintentionally doped n-ZnO (N d = 1.79 × 1016 - 5.76 × 1018 cm-3). For n-ZnO layers with carrier concentrations in excess of 8.04 × 1017 cm-3, as-deposited ITO contacts produce good Ohmic behavior. However, as-deposited ITO contacts to n-ZnO with carrier concentrations less than ∼4 × 1017 cm-3 yield non-Ohmic behaviors. We show that when annealed at 400 °C in a nitrogen ambient, the ITO contacts to ZnO (with carrier concentrations exceeding 4.08 × 1017 cm-3) become Ohmic with a specific contact resistivity in the range of 8.76 × 10-3 - 1.51 × 10 -4 Ωcm2. Based on carrier transportation theory, we describe the carrier concentration and the annealing temperature dependence of the carrier transport mechanisms.

Original languageEnglish
Pages (from-to)740-743
Number of pages4
JournalJournal of the Korean Physical Society
Issue number2
Publication statusPublished - 2009 Feb 1



  • Electronic transport
  • Indium tin oxide
  • Ohmic contact
  • Zinc oxide

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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