Ferroelectricity enhanced self-powered solar-blind UV photodetector based on Ga2O3/ZnO:V heterojunction

Abstract

Ferroelectric materials with spontaneous polarization can change the direction of the depolarizing field by applying the external electric field, showing great potential in regulating the photoelectric process. In this work, self-powered solar-blind ultraviolet (UV) photodetectors (PDs) based on Ga2O3/ZnO:V heterojunction were fabricated by the pulsed laser deposition method. The photoresponse behaviors of the Ga2O3/ZnO:V PDs can be modulated by the induced ferroelectric polarization field in ZnO:V. In the downward poling state, the Ga2O3/ZnO:V PD showed a responsivity of 95.53 mA/W and a detectivity of 1.18 × 1012 Jones to 260 nm light, which were 3.2 times higher than that of the unpoled state. Moreover, the rise/decay time was shortened from 10.3 μs/1.76 ms to 6.2 μs/0.43 ms. The improved performance of the Ga2O3/ZnO:V PD had been attributed to the increase of the built-in electric field and the widening of the depletion region under the influence of the depolarization field, which could be beneficial to the separation and transport of photogenerated carriers at the heterojunction interface. This work could be of great value for the design and fabrication of ferroelectricity-enhanced self-powered UV photodetectors.