Current transport mechanism of heterojunction diodes based on the sol–gel p-type ZnO and n-type Si with H2O2 treatment

The present work reports the fabrication and detailed electrical properties of heterojunction diodes based on the sol–gel p-type ZnO and n-type Si. The p-type ZnO/n-type Si diode without H2O2 treatment showed a poor rectifying behavior with an ideality factor (n) of 6.4 and high leakage. n > 2 implies that the interfacial defects influence the electronic conduction through the device. However, the p-type ZnO/n-type Si diode with H2O2 treatment showed a good rectifying behavior with n of 1.6 and low leakage. Such an improvement indicates that a good passivation is formed at the interface as a result of the reduction of the defect density. These experimental demonstrations suggest that it may be possible to minimize the adverse effects of the interface states to obtain functional devices using H2O2 treatment.

► The p-ZnO/n-Si diode without H2O2 treatment showed a poor rectifying behavior.
► The p-ZnO/n-Si diode with H2O2 treatment showed a good rectifying behavior.
► The interfacial defects of the p-ZnO/n-Si diode were controlled by H2O2 treatment.
► Such an improvement indicates that a good passivation is formed at the interface.