Ultrafast light-induced formation of a metastable hidden state in bismuth vanadate
Abstract
Bismuth vanadate (BiVO) is a key photocatalyst for solar fuel applications, yet fundamental questions remain regarding the nature of photogenerated polaronic states and the lattice dynamics that govern its light-to-chemical pathways. Here, we use femtosecond optical pump-X-ray probe measurements to track the photoinduced electronic and structural dynamics in BiVO across multiple length and time scales. Transient X-ray absorption spectroscopy captures sub-picosecond electron localization within VO tetrahedra, consistent with small polaron formation, whereas time-resolved X-ray diffraction reveals a slower, multi-picosecond lattice reorganization into a hidden photoexcited state that is structurally distinct from both the monoclinic ground state and the high-temperature tetragonal phase. Supported by density functional theory, we show that hole-lattice interactions dynamically reduce the ground state monoclinic distortion, stabilizing the hidden state. Our results demonstrate that electron- and hole-lattice coupling jointly shape the excited state landscape, with implications for carrier transport, interfacial energetics, and light-to-chemical energy conversion pathways.
Keywords
Cite
@article{arxiv.2512.08287,
title = {Ultrafast light-induced formation of a metastable hidden state in bismuth vanadate},
author = {Viktoria F. Kunzelmann and Verena Streibel and Philip Schwinghammer and Philipp Kollenz and Burak Guzelturk and Franziska S. Hegner and Lissa Eyre and Frederico P. Delgado and Tsedenia A. Zewdie and Markus W. Heindl and Danyellen D. Monteiro Galindo and Daniel Sandner and Guanda Zhou and Elise Sirotti and Stanislav Bodnar and Yifeng Jiang and Yohei Uemura and Tobias Eklund and Frederico Lima and Xinchao Huang and Doriana Vinci and Fernando Ardana Lamas and Peter Zalden and Hristo Iglev and David A. Egger and Felix Deschler and Ian D. Sharp},
journal= {arXiv preprint arXiv:2512.08287},
year = {2025}
}