Ohmic contact of Au/p-CdZnTe

The effect of different annealing time at 60°C in air on the Ohmic contact of Au/p-CdZnTe (CZT) was investigated. By measuring I-V curves, it was found that Au/p-CZT had excellent Ohmic performance after 2 h annealing. From SEM and XPS analyses, Au was diffused into the CZT bulk during the annealing, and occupied the Cd sites as acceptors. Thus, heavy doped p-type layer was formed, and M-p⁺-p Ohmic contact was obtained. During the annealing, Cd and Te were hardly diffused into the Au layer and as-diffused Au didn't form any compounds with the elements in CZT bulk. At the same time, Te of about 27.01% in CZT profile was oxidated to form TeO₂ with passivation action.