Anion-substituted Hybrid Zinc Halides with Remarkable Dielectric Switches

Thermo-responsive dielectric switching hybrid halides, displaying reversible dielectric bistability, have recently made them highly versatile and attractive for their structural tunability and rich functional properties. However, the substantial improvement of the dielectric switching operating range is limited near room temperature, and obtaining ultra-wide dielectric switching temperature region is a major challenge. Herein, a remarkable dielectric switching effect is reported with ultra-wide dielectric switching temperature region in a hybrid halide system, caused by dipolar orientational polarization ascribing order-disorder phase transitions. The new A₂BX₄ hybrid halide [C₆H₅(CH₂)₄NH₃]₂ZnBr₄ (4PBA-ZnBr₄) with an ultra-wide dielectric hysteresis loop of about 55 K near room temperature is designed successfully through halogen substitution. Meanwhile, structurally similar hybrid materials 4PBA-ZnI₄ were designed as controls. More interestingly, the crystal structure, phase transition temperature (Tc), dielectric and semiconductor properties exhibit significant discrepancies as the halogen atoms vary from Br to I. This discovery provides an efficiently regulated anionic framework to construct hybrid halides with ultra-wide high dielectric switching and reliable cycling stability by assembling with various cations, making them potentially excellent candidates for highly responsive room temperature smart switches or transducer devices.