Semi-conductive, Switchable Dielectric and Photoluminescent Properties of Two High-Temperature Phase Transition...

Bistable switches (electrical switching between "ON" and "OFF" bistable states) have gradually developed into an ideal category of highly intelligent materials, due to their significant applications in optical technology, signal processors, data storage and other switchable media applications in the field of electrical devices. Here, we successfully designed and synthesized [(FC₆ H₄ C₂ H₄ NH₃ )₂ MCl₄ ]_n (FC₆ H₄ C₂ H₄ NH₃ ⁺ )=deprotonated 4-fluoro- phenethylamine; M=Cd (1), Mn (2)), which realized the coupling of thermo-dielectric switching characteristics, semi-conductor characteristics and photo-luminescent properties. DSC (differential scanning calorimetry) and dielectric measurements show that 1 is a sensitive dielectric bistable switch between the high dielectric (ON) and low dielectric (OFF) states. The temperature-variable single crystal structure shows that the both 1 and 2 undergo a high-temperature reversible phase transition around 383 K/380 K, which is caused by the order-disordered transformation of organic cations and the slight distortion of the inorganic framework. In particular, 1 shows outstanding switchable dielectric behavior and semiconducting properties. Further, 1 and 2 emit strong green and yellow luminescence at 527 and 595 nm, respectively.