Photo-enhanced flexoelectricity or flexoelectricity-enhanced photovoltaic effect, named photo-flexoelectric, is an interesting topic and has application potential in photo-electro-mechanical devices. However, this effect is far from being well understood. In this work, we demonstrate the photoflexoelectric effect in perovskite-structured SrTiO3 (STO) single crystal and reveal the coupling mechanism between its photovoltaic and flexoelectric effect. Driven by the flexoelectric field, light-induced electrons can tunnel through the Schottky junction at the Au/STO interface, giving rise to enhanced flexoelectricity, i.e., photoflexoelectric effect. Thermal annealing in vacuum induces oxygen vacancies in STO and results in stronger light absorption and enlarged photoflexoelectric effect.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)