Above-room-temperature switching of quadratic nonlinear optical properties in a Bi–halide organic–inorganic hybrid

Abstract

Organic–inorganic hybrid nonlinear optical (NLO) switches have recently attracted intensive attention as potential candidates for optical applications. Herein, by introducing an organic triamine cation, we obtain a lead-free Bi-based organic–inorganic hybrid, (C₄H₁₆N₃)BiBr₆ (1), which behaves as a promising above-room-temperature modulator of quadratic NLO responses. More importantly, 1 possesses a remarkable NLO switching contrast of up to ∼35 and a notable switching repeatability. Additionally, microscopic single-crystal structural analyses reveal that the coordinated distortion of inorganic [BiBr₆]³⁻ octahedra and the order–disorder transformation of the flexible organic triamine cations synergistically contribute to its NLO switching behavior. We believe that this work will promote the development of high-performance NLO switching materials based on devisable organic–inorganic metal–halide hybrids.