Enhanced Performance of Self-Powered Ga<sub>2</sub>O<sub>3</sub>/ZnO:V Heterojunction Solar-Blind Ultraviolet Photodetectors by Coupling Ferroelectricity and Piezoelectricity
Hongbin Wang, Jiangang Ma, Yurui Han, Peng Li, Weizhen Liu, Bingsheng Li, Haiyang Xu, Yichun Liu
Abstract
Ferroelectric materials have aroused increasing interest in the field of self-powered ultraviolet (UV) photodetectors (PDs) for their switchable spontaneous polarization. However, the utilization of ferroelectric materials to modulate the built-in electric field and energy band at the junction interface has rarely been investigated. Herein, we design and fabricate self-powered solar-blind UV PDs based on a Ga 2 O 3 /ZnO:V heterojunction. The performance of the Ga 2 O 3 /ZnO:V PD is significantly enhanced through the reasonable coupling of ferroelectricity and piezoelectricity within the ZnO:V film. The device at 260 nm exhibits excellent photoelectric properties with high peak responsivity of 64.5 mA/W, a specific detectivity of 3.8 × 10 10 Jones, and a rise/decay time of 1.9/45.2 μs, together with reproducibility and stability. Systematical energy band diagram analysis reveals that the excellent performance of Ga 2 O 3 /ZnO:V PD can be attributed to the driving forces arising from the addition of the depolarization field and piezoelectric field, which increases the intensity of built-in electric field and promotes the separation and transport of photogenerated carriers at the heterojunction interface. The findings of our research provide a novel avenue and valuable guidance for the design of high-performance self-powered photodetectors.