LAUSR

Molecular ferroelectrics are attracting tremendous interest because of their low cost, mechanical flexibility, easy processing, low weight, and low acoustical impedance. Moreover, their combination of ferroelectric and optical properties has led to investigations of their many potential applications, such as low-energy electron excitation and field emission displays. However, luminescent molecular ferroelectrics have rarely been reported, except for several AMnX3-type or lanthanide ion-based luminescent ferroelectrics. Here, we report the first above-room-temperature phosphonium-based molecular ferroelectric perovskite, [(CH3)4P]CdCl3 (1), with a high Curie temperature (Tc = 348 K) and moderate remanent polarization (Pr = 0.43 μC/cm2). Using piezoresponse force microscopy (PFM), the typical stripe-like domains of ferroelectrics can be observed. Moreover, 1 exhibits orange luminescence under UV excitation after doping with Sb3+, which represents a first step toward realizing luminescence-enhanced molecular ferroelectrics with various wavelengths. These results will inspire the further exploration of phosphonium-based ferroelectrics and pave the way toward practical applications in ferroelectric luminescence and/or multifunctional devices.Ferroelectrics: Low-cost molecules get ready to glowA molecule that can be manipulated with electric fields while simultaneously acting as a light-emitting phosphor could find use in next-generation photovoltaics. Ferroelectric materials are positively charged on one end and negatively on the other. Recent work suggests that the spontaneous dipoles formed by these charges can help engineer high outputs in solar cells. Lin Zhou from Southeast University in Nanjing, China, and colleagues have developed a ferroelectric with improved characteristics for device manufacturing. The team combined organo-phosphorus cations with trichlorocadmate anions to produce an organic–inorganic composite that can be synthesized at room temperature, instead of the energetically intense conditions needed for conventional all-inorganic ferroelectrics. Adding small portions of antimony ions to the molecule generated strong luminescent emissions that may be used to concentrate and direct solar radiation.A phosphonium-based perovskite, [(CH3)4P]CdCl3, is designed and synthesized, which shows ferroelectric characteristics below 348 K as revealed by the observation of typical stripe-like domains and hysteresis loops. By doping with Sb3+, this material exhibits orange luminescence under UV excitation. This work will open new avenues in designing multifunctional luminescent molecular ferroelectrics.