High phase transition temperature and photoluminescence properties in low-dimensional molecular perovskite ferroelastic crystals

Abstract

Ferroelastic materials, as a relative of ferroelectric and ferromagnetic materials, have attracted great attention in developing materials with multifunctions and smart devices for many high-end realms. In this work, we synthesized two new one-dimensional ABX₃ type molecular perovskite crystals, N,N-dimethylpropargylaminium CdCl₃ (DMPACdCl₃) and N,N-dimethylpropargylaminium MnCl₃ (DMPAMnCl₃). DMPACdCl₃ undergoes a reversible mmmF2/m type ferroelastic phase transition at 358 K, accompanied by an order–disorder transition of DMPA cations. The ferroelasticity of DMPACdCl₃ has been verified by the evolution of observable ferroelastic domains. When the B-site metal is substituted by Mn²⁺, the DMPAMnCl₃ crystal exhibits structural phase transition behavior similar to that of DMPACdCl₃ but occurs at a higher phase transition temperature (T_tr = 396 K) with a significant enhancement of 38 K. Besides, DMPAMnCl₃ emits strong red luminescence at room temperature, with a photoluminescence quantum yield (PLQY) of 20.1%. This work highlights the regulation of phase transition temperature and photoluminescence in one-dimensional molecular perovskites by B-site metal substitution and offers significant inspiration for developing multiple function coupling materials for promising optoelectronics and smart devices.