Polar molecules realignment in CH3NH3PbI3 by strain gradient

In this Letter, we show, both theoretically and experimentally by the molecule dynamics calculation and in-situ Raman scatting, respectively, that the polar molecules in CH3NH3PbI3 perovskite, upon bending, would form a stable molecule alignment, suggesting that hybrid organic–inorganic perovskites are promising candidates for semiconducting ferroelectric materials. Our research provides an alternative paradigm for determining of polarization shifting in ferroelectrics, especially those with large electrical conductivity.