We report on the formation of ohmic contacts to As-doped ZnO layers using a Pt/indium tin oxide (ITO) scheme. The As-doped ZnO layer shows p-type conductivity with carrier concentrations of 5.12-9.74×1016 cm-3 when annealed at 25-400°C for 1 min in nitrogen ambient. However, the ZnO layers exhibit n-type characteristics with carrier concentration ca.1018-ca.1019 cm-3 when annealed at 500-800°C. The Pt/ITO contacts produce contact resistivities of 8.0×10-4 - 3.5×10-3 Ω cm2 upon annealing at 300-600°C. Possible ohmic formation mechanisms for the Pt/ITO contacts to the As-doped ZnO layers are described and discussed.
ASJC Scopus subject areas
- Materials Science(all)