Preparation and Photoelectric Properties of p-Cu2O/n-ZnO Thin Film Heterojunction

Abstract

P-Cu 2 O/n-ZnO thin film heterojunction was fabricated onto ITO glass substrate by radio frequency magnetron sputtering. Meanwhile, the characteristics of p-Cu 2 O/n-ZnO thin film heterojunction were studied systematically. The results show that ZnO thin films have the c-axis preferred orientation, and Cu2O thin films have the preferred orientation along the (110). The optical band gap energies of ZnO and Cu2O thin films are 3.3 eV and 2.8 eV, respectively. The carrier concentrations of Cu2O and ZnO thin films are thin films are $6.41\times 10^{15} {\mathrm {cm}}^{-3}$ and $1.4\times 10^{18} {\mathrm {cm}}^{-3}$, the values of resistivity are 6.41 $\Omega\bullet {\mathrm {cm}}$ and 1.4 $\Omega\bullet {\mathrm {cm}}$, respectively. Furthermore, the results demonstrated that the absorption intensity of the Cu 2 O/ZnO thin film heterojunction is significantly enhanced in visible region compared with the ZnO thin films. The forward current of the heterojunction increases obviously under illumination.