Preparation and temperature-dependent photoelectrical properties of VO2/AZO heterojunctions

Abstract The preparation of n-N homotypic heterojunction by growing n-type VO 2 film on N-type Al-doped ZnO substrate using DC magnetron sputtering and post-annealing was reported in this paper. The composition and microstructure of the VO 2 /AZO heterojunction were measured by XRD and SEM. The photoelectrical properties and the phase transition properties were tested by adjusting voltage at different temperature. The forward current was perfectly fitted on the thermionic emission model and the breakdown voltage was about 5 V at 20 °C. Meanwhile, the threshold voltage of current mutation was 3 V at 20 °C and decreased with increasing temperature until it completely disappeared at 60 °C. The voltage dependence transmittance of VO 2 /AZO heterojunction at 1310 nm was obtained. It indicated that the decrease of transmittance is the double effect of thermally induced phase transition and electrically induced phase transition.