Electrically modulated photoresponse and optically modulated electroresistance in a ferroelectric heterostructure with PbZr_0.2Ti_0.8O₃ barriers

Ferroelectric heterostructures hold great promise for developing multifunctional memristors and optoelectronic devices. In this study, we report a ferroelectrically modulated photoresponse and optically modulated electroresistance behaviors in the Pt/PbZr_0.2Ti_0.8O₃(PZT)/Nb-doped SrTiO₃ (NSTO) heterostructure. The short-circuit photocurrent rises from 28 nA (after poling at +5 V) to 345 nA (after poling at -5 V) when illuminated with 360 nm of 10 mW·cm^-2, exhibiting a massive photocurrent variation ratio of 1230%. This result can be attributed to the modulation of the ferroelectric polarization on the built-in field at the PZT/NSTO interface, which impacts the separation of photogenerated carriers. Furthermore, the heterostructure has a large high/low resistance ratio of 6 × 10⁵%, which decreases to 2 × 10⁴% when illuminated with 360 nm light. This finding is attributed to ferroelectric polarization and light illumination modulating the barrier height and width. Overall, this research suggests a promising strategy for developing self-powered heterojunction photodetectors and multifunctional memory devices.