Study on PL and electrical properties of Au/p-CZT crystal

By comparing the photoluminescence (PL) spectra of etching and passivation surface of the p-CZT, it is confirmed that using NH₄F/H₂O₂ as agent, the passivation treatment minimized the surface trap state density and decreased the deep level defects related to recombination of Cd vacancies. I-V and C-V characteristics of Au/p-CZT contacts with different surface treatments were measured by Agilent 4339B high resistance meter and Agilent 4294A precision impedance analyzer, respectively. It was shown that etching and passivation could increase the barrier height of the Au/p-CZT and decrease the leakage current. The major reason was that passivation increased the barrier height of Au/p-CZT contacts and the possibility for electrons through the TeO₂ oxide was smaller.