Long-lived photoinduced polar states in metal halide perovskites
Yixuan Dou, Xiaoming Wang, Nicholas W. Smith, Piush Behera, Rathsara Herath Mudiyanselage, Burak Güzeltürk, Donald A. Walko, Yannick Pleimling, Sunhao Liu, Nicholas Nici, Carla Slebodnick, Bogdan Dryzhakov, Bin Hu, Archana Raja, R. Ramesh, Giti A. Khodaparast, Yanfa Yan, Li Na Quan
Abstract
Ferroic polarization in hybrid perovskites is crucial for enhancing photovoltaic performance and developing potential electronic applications. Controlling ferroic polarization with an optical field enables probing of ferroic polarization without the unwanted interface ionic effects caused by electronic contacts. This study employs ultrafast near-infrared photoexcitation to control dynamic structural transitions in soft single crystalline hybrid Cu (II) halide perovskites, achieving a long-lived polar state (beyond 104 s) at room temperature. We probe reversible long-lived polar domains under near-infrared photoexcitation using in-situ second harmonic generation microscopy. Theoretical calculation informs the polar lattice microstrain likely induced by anisotropic structure deformation in octahedral copper halide under near-infrared photoexcitation. The reversible slow structure deformation is further confirmed by in-situ photo-induced X-ray diffraction measurement. This work provides a material platform for understanding, controlling, and probing polarization under photoexcitation. Our methodology enables the identification of previously undiscovered polar phases in ferroelectric halide perovskites. Dou et al. report photo-induced long-lived polar states in octahedral copper-based hybrid perovskites with Jahn-Teller distortion. These states arise from reversible light-induced slow structural deformation induced by polar lattice microstrain formation.