Two Lead‐Free Organic‐Inorganic Hybrid Halides: Exploring Dielectric Switching and Photoluminescence Integrated in Crystals

Organic‐inorganic hybrid halides have attracted widespread attention in optics, electricity, magnetism. In particular, some of them can have a combination of luminescence and switching characteristics, providing a potential for a single device unit to meet multiple application requirements. Herein, we reported two novel organic‐inorganic hybrid single‐crystals (CTA)2ZnCl4 (1; CTA=3‐chloro‐2‐hydroxypropyltrimethylammonium) and (CTA)2[InCl5(H2O)] ⋅ H2O (2), exhibiting long lifetime blue emission upon UV excitation. Systematic characterizations of the compounds including crystal structure, phase transition, thermal, and photoluminescence properties were carried out. DSC tests detected that 1 had a reversible phase transition accompanied by obvious heat anomaly, at 411/391 K on the heating/cooling process, leading to its good switchable dielectric response with striking anisotropy along various crystallographic axis. This work offered a new example on the effective design of multifunctional response materials. Two environmentally friendly hybrid organic‐inorganic hybrid halides (CTA)2ZnCl4 and (CTA)2[InCl5(H2O)] ⋅ H2O were successfully synthesized, both which have shown blue light emission with a long lifetime of 0.3 s, indicating a visible optical response. Notably, (CTA)2ZnCl4 also exhibits a sensitive switchable dielectric property, which allows it to be a good multifunctional response material.