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

P-Cu ₂ O/n-ZnO thin film heterojunction was fabricated onto ITO glass substrate by radio frequency magnetron sputtering. Meanwhile, the characteristics of pCu ₂ O/n-ZnO thin film heterojunction were studied systematically. The results show that ZnO thin films have the c-axis preferred orientation, and Cu ₂ O thin films have the preferred orientation along the (110). The optical band gap energies of ZnO and Cu ₂ O thin films are 3.3 eV and 2.8 eV, respectively. The carrier concentrations of Cu2O and ZnO thin films are 6.41×10 ¹⁵ cm ^-3 and 1.4×10 ¹⁸ cm ^-3 , the values of resistivity are 6.41 Ω.cm and 1.4 Ω.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.