Ferroelectric photovoltaic characteristics of pulsed laser deposited 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3/ZnO heterostructures

[Display omitted] •0.5BZT-0.5BCT/ZnO heterostructures exhibited enhanced photovoltaic (PV) properties.•The enhanced PV effect is attributed to the perfect alignment of the internal fields.•The influence of polarization interfacial charge coupling on the band structure is highlighted.•No diffusion at the 0.5BZT-0.5BCT/ZnO interfaces is observed as evidenced EELS. In this work, we investigate the photovoltaic response of Pt/0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3(0.5BZT-0.5BCT)/ITO structures through the insertion of a semiconductor ZnO layer at different positions. The values of short-circuit photocurrent density (Jsc) of the Pt/ZnO/0.5BZT-0.5BCT/ITO, Pt/0.5BZT-0.5BCT/ZnO/ITO and Pt/ZnO/0.5BZT-0.5BCT/ZnO/ITO capacitors are around 5.31, 0.0034 and 0.052 mA/cm2, respectively. The enhanced photovoltaic (PV) effect is observed when ZnO layer is inserted between Pt and the 0.5BZT-0.5BCT layer. The built-in field developed at the ZnO/ferroelectric interface in the same direction of the depolarizing field, provides a favorable electric potential for the efficient separation and transportation of photo generated e-h pairs. Furthermore, the polarization-dependent interfacial coupling effect enhances PV effect, which is confirmed by investigating the role of polarization flipping on switchable photo response. This work provides an efficient pathway in tuning the PV response in ferroelectric-based solar cells.