Ferroelectric Properties and Bulk Photovoltaic Effects of 2D Hybrid Halide Perovskites

Résumé fourni par la source

Two-dimensional (2D) hybrid organic-inorganic halide perovskites have emerged as a new class of tunable 2D semiconductors with the potential to combine excellent optoelectronic properties with symmetry-enabled properties such as ferroelectricity. Although many lead-based ferroelectric 2D halide perovskites have been studied so far, there is strong motivation to develop non-toxic lead-free perovskites. In this work, we report the ferroelectricity of 2D hybrid perovskites enabled by the rational design of noncentrosymmetric hybrid structures, including examples of lead-free tin-based 2D perovskites. Polarization-electric field hysteresis and second harmonic generation measurements confirm they are ferroelectric at room temperature. The frequency-dependent ferroelectric properties of lead- and tin- based pervoskites are studied, providing switching speed of reversible change of ferroelectric domain. Furthermore, in the photodetector devices fabricated with these new 2D perovskites, we observe non-zero short-circuit photocurrents without an external voltage, essentially a bulk photovoltaic effect (BVPE). The short-circuit current is switchable and controllable with poling voltage, which shows potential multiple ferroelectric states. As the first direct experimental observation of the spontaneous ferroelectric polarization of tin-based 2D hybrid perovskites, this work opens up environmentally friendly 2D tin halide perovskites for ferroelectricity and other physical property studies and could enable potential spin-orbitronic and neuromphoric devices in the future.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.