Electrical properties of anisotype heterojunctions $n$-CdZnO/$p$-CdTe

Anisotype surface-barrier $n$-Cd$_{0.5}$Zn$_{0.5}$O/$p$-CdTe heterojunctions are fabricated by the high-frequency sputtering of a Cd$_{0.5}$Zn$_{0.5}$O alloy film onto a freshly cleaved single-crystal CdTe surface. The main electrical properties of the heterojunctions are studied and the dominant mechanisms of charge transport are established, namely, the multistage tunnel-recombination mechanism under forward bias, Frenkel–Pool emission, and tunneling under forward bias. The influence of the surface electrically active states at the heterojunction interface is analyzed and their surface concentration is evaluated: $N_{ss}\sim$ 10$^{14}$ cm$^{-2}$.