The Effect of Multi‐Fields Synergy from Electric/Light/Thermal/Force Technologies on Photovoltaic Performance of Ba_0.06Bi_0.47Na_0.47TiO₃ Ferroelectric Ceramics via the Mg/Co Substitution at A/B Sites

Abstract

Currently, it is widely reported that the photovoltaic effect in ferroelectric materials can be promoted by the application of a piezoelectric force, an external electric field, and intense light illumination. Here, a semiconducting ferroelectric composition is introduced, (1−x) Ba0.06Bi0.47Na0.47TiO3‐xMgCoO3 (abbreviated as xMgCo, where x = 0.02–0.08), synthesized through Mg/Co ions codoping. This process effectively narrows the optical bandgaps to a spectrum of 1.38–3.06 eV. Notably, the system exhibits a substantial increase in short‐circuit photocurrent density (Jsc), by the synergy of the electric, light, and thermal fields. The Jsc can still be further enhanced by the extra introduction of a force field. Additionally, the Jsc also shows an obvious increase after the high field pre‐poling. The generation of a considerable number of oxygen vacancies due to the Co2+/Co3+ mixed valence state (in a 1:3 ratio) contributes to the reduced optimal bandgap. The integration of Mg2+ ion at the A‐site restrains the loss and sustains robust ferroelectricity (Pr = 24.1 µC cm−2), high polarizability under an electric field, and a significant piezoelectric coefficient (d33 = 102 pC N−1). This study provides a novel perspective on the physical phenomena arising from the synergy of multiple fields in ferroelectric photovoltaic materials.