2026/03/04 by Yonghui Wu, Jie Tu, Jing Xia +13 · 1 voice
Materials Science · Engineering · #Multiferroics and related materials #Perovskite Materials and Applications #2D Materials and Applications
paper · pdf · doi:10.1007/s40820-026-02105-y
openalex publication_date 2026/03/04 · openalex created_date 2026/03/05 · openalex updated_date 2026/07/29
Abstract Double perovskite films offer significant potential for multiferroic and ferroelectric photovoltaics due to their structural tunability. This study employs an aliovalent substitution strategy, partially replacing Bi with Pb in Bi 2 FeMnO 6 (BFMO), to disrupt charge balance and local polarization while maintaining the host lattice. Pb incorporation simultaneously modulates the chemical states of all constituent elements, inducing pronounced lattice distortion and positive chemical strain. Unpoled Pb-BFMO films exhibit exceptional photovoltaic performance under 80 mW cm −2 illumination, achieving a short-circuit current density (| J SC |) of 192 μA cm −2 and an open-circuit voltage (| V OC |) of 0.525 V. This represents a 109-fold increase in intrinsic J SC and a fourfold enhancement in V OC compared to pure BFMO. The | J SC | demonstrates electric field tunability via polarization switching, reaching 320 μA cm −2 under negative polarization, the highest reported J SC for sub-100 nm single-layer ferroelectric films under white light. High-resolution high-angle annular dark-field scanning transmission electron microscopy, synchrotron-based reciprocal space mapping and X-ray absorption spectroscopy analyses collectively confirm the coupling of crystal distortion, chemical strain, and valence state alterations. The synergy between chemical strain and ionic valence states effectively engineers the bandgap and enhances photovoltaic response, which unlocks new application pathways for perovskite materials in optical memory devices and sustainable energy systems.