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)₂CHCH₂NH₃]₂PbCl₄, which exhibits a sharp first-order phase transition at 302 K, superior spontaneous polarization (>4.8 μC/cm²) and relatively small coercive field (<15 kV/cm). Strikingly, a large isothermal entropy change ΔS of 25.64 J/kg/K and adiabatic temperature change ΔT of 11.06 K under a small electric field ΔE of 29.7 kV/cm at room temperature are achieved, with giant electrocaloric strengths of isothermal ΔS/ΔE of 0.86 J·cm/kg/K/kV and adiabatic ΔT/ΔE of 370 mK·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.

电场驱动的电热效应在实现高效固态制冷方面具有巨大潜力。然而，大多数已知的电热材料在室温附近表现出相对较差的冷却性能，这阻碍了它们的进一步应用。新兴的混合钙钛矿铁电体系列具有出色的结构多样性、大的热交换和广泛的性能稳定性，提供了一个理想的平台。在此，我们报告了在设计的混合钙钛矿铁电体 [(CH ₃ ) ₂ CHCH ₂ NH ₃ ] ₂ PbCl _{4 中}接近室温的异常大的电热效应，其在 302 K 处表现出明显的一阶相变、优异的自发极化 (>4.8 μ C/cm ² ) 和相对较小的矫顽场 (<15 kV/cm)。引人注目的是，在室温下 29.7 kV/cm的小电场 Δ E下，实现了 25.64 J/kg/K的大等温熵变化 Δ S和11.06 K 的绝热温度变化 Δ T，并具有巨大的等温 Δ电热强度S /Δ E为 0.86 J·cm/kg/K/kV 和绝热 Δ T /Δ E370 mK·cm/kV，比传统铁电体大。这项工作提出了一种设计混合钙钛矿铁电体的通用方法，并提供了一系列具有潜在显着电热性能的候选材料，可用于室温固态制冷。