Abstract
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 language | English |
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Pages (from-to) | 740-743 |
Number of pages | 4 |
Journal | Journal of the Korean Physical Society |
Volume | 54 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2009 |
Externally published | Yes |
Keywords
- Electronic transport
- Indium tin oxide
- Ohmic contact
- Zinc oxide