Multi-functional hybrid perovskites with triple-channel switches and optical properties

Abstract

Multi-functional switching materials, possessing a high transition temperature, can work in a relatively wide temperature range, particularly for practical applications under extreme thermal conditions such as automotive, aerospace and power generating industries. The halogen substitution strategy, known as an effective molecular modification method, can introduce halogen atoms into cations to increase the energy barrier of cationic motion for obtaining compounds with high transition temperature. Herein, by halogenating organic cations of the prototype (N,N-dimethylmorpholinium)PbBr₃ (compound 1), we report two triple-channel dielectric/SHG/PL switching materials (N-ClCH₂-N-methylmorpholinium)PbBr₃ and (N-BrCH₂-N-methylmorpholinium) PbBr₃ (2 and 3). These compounds adopt a one-dimensional perovskite structure constituted by face-sharing octahedral [PbBr₆]⁻ chains and organic cations, and could emit orange-red light under ultraviolet light excitation. The phase transition temperatures of 2 and 3 achieve a very high value: ca. 380 K. Meanwhile, good nonlinear optical properties (SHG) and optimized PL properties were obtained. Thus, multi-functional hybrid perovskites simultaneously with triple-channel switches and optical properties were successfully fabricated. This work might provide a new impetus for designing new organic hybrid perovskites with multi-channel switching behavior and prominent optical properties.