Strong anisotropic second-order nonlinear optical responses in 0D lead-free chiral perovskite single-crystalline microwire arrays

Abstract

Low-dimensional hybrid organic–inorganic chiral perovskites with intrinsic non-centrosymmetric structures have shown promising potential for second-order nonlinear optical applications due to their structural diversity and large lattice distortions. Simultaneously, “structure-level” low-dimensional single crystal perovskites have attracted wide attention to meet the increasing demand of on-chip integrated nonlinear optical devices. Herein, we synthesized two new chiral hybrid 0D perovskites (R/S-MBA)₄Bi₂Cl₁₀ based on the non-toxic element bismuth by introducing chiral R/S-MBA as the organic component. The highly ordered assembly microwire arrays were further prepared using a capillary-bridge confined technique. These high-crystallinity chiral perovskite microwire arrays preserve their structures with high distortion levels and achieve high-efficiency frequency conversion across a wide range of bands and different polarization states with a high polarization ratio of up to 0.992, which is superior to those of the corresponding polycrystalline films that cause undesirable light scattering. Such non-toxic Bi-based low-dimensional chiral perovskite single-crystalline microwire arrays with excellent NLO performances might provide a strategy for NLO-integrated applications in advancing photonic devices.