Giant room temperature electrocaloric effect in a layered hybrid perovskite ferroelectric: [(CH3)2CHCH2NH3]2PbCl4

Electrocaloric effect driven by electric fields displays great potential in realizing highly efficient solid-state refrigeration. Nevertheless, most known electrocaloric materials exhibit relatively poor cooling performance near room temperature, which hinders their further applications. The emerging family of hybrid perovskite ferroelectrics, which exhibits superior structural diversity, large heat exchange and broad property tenability, offers an ideal platform. Herein, we report an exceptionally large electrocaloric effect near room temperature in a designed hybrid perovskite ferroelectric [(CH3)(2)CHCH2NH3](2)PbCl4, which exhibits a sharp first-order phase transition at 302 K, superior spontaneous polarization (>4.8 mu C/cm(2)) and relatively small coercive field (<15 kV/cm). Strikingly, a large isothermal entropy change Delta S of 25.64 J/kg/K and adiabatic temperature change Delta T of 11.06 K under a small electric field Delta E of 29.7 kV/cm at room temperature are achieved, with giant electrocaloric strengths of isothermal Delta S/Delta E of 0.86 J center dot cm/kg/K/kV and adiabatic Delta T/Delta E of 370 mK center dot cm/kV, which is larger than those of traditional ferroelectrics. This work presents a general approach to the design of hybrid perovskite ferroelectrics, as well as provides a family of candidate materials with potentially prominent electrocaloric performance for room temperature solid-state refrigeration. Most known electrocaloric materials show relatively poor cooling performance near room temperature, hindering their applications. Here, the authors achieve large electrocaloric effect near room temperature in a hybrid perovskite ferroelectric, useful for high-performance solid-state refrigeration.