Effects of annealing on the properties of Au-Cd_0.9Zn _0.1Te contacts

Au-Cd_0.9Zn_0.1Te contacts were annealed for 10 min at 100, 200 and 300°C, respectively. The effects of annealing have been analyzed with photoluminescence (PL) spectra, leakage current-bias voltage (I-V) characteristic and leakage current-time (I-t) characteristic. PL spectra indicate that there are more Au-related complexes and Cd vacancies (Zn vacancies) produced in Au-Cd_0.9Zn_0.1Te contacts during the annealing. These complexes and vacancies are responsible for the decrease of leakage current, which is revealed by I-V measurement, because they can trap free charge and improve the recombination rate of charge effectively. The I-V measurement also shows that the ohmic characteristic of Au-Cd _0.9Zn_0.1Te contacts is improved obviously by the annealing at 100 and 200°C and deteriorated seriously by the annealing at 300°C. In addition, I-t curves suggest that annealing can improve the stability of leakage current remarkably.