The compact, integrated solid-state refrigeration using the electrocaloric effect (EC) has gained wide interest in electronics, healthcare, and defense sectors for its low power consumption. Despite rising interest, existing electrocaloric refrigeration materials typically face challenges including low efficiency and complex heat transfer dynamics. Here, we present a novel approach to achieve high cooling efficiency within a single electric field cycle via positive-negative electrocaloric synergy effects. A high-performance conversion of positive EC effect (ΔT_max ∼ 7.54 K) to negative EC effect (ΔT_max ∼ −11.85 K) over a wide temperature range (303 ∼ 443 K) is exampled in sandwich heterojunction-thin-film structure of Ca_0.2Zr_0.8O_1.8/85 %Pb(Mg_1/3Nb_2/3)O₃-15 %PbTiO₃/Ca_0.2Zr_0.8O_1.8. This linear dielectric dead layer of Ca_0.2Zr_0.8O_1.8 aids in the polarization reversal of pinned domains at the interfaces and promotes the emergence of polar nanodomains within this dead layer, enabling the leveraging of positive and negative EC synergy effects in a single electric field cycle. Our study enriches the functionalities of heterostructure interface, offering a distinctive approach to realize high-performance chip level electrocaloric films.

中文翻译：

---

通过异质结释放巨大的负电热效应的力量


利用电热效应 （EC） 的紧凑型集成固态制冷因其低功耗而在电子、医疗保健和国防领域引起了广泛关注。尽管人们的兴趣日益浓厚，但现有的电热制冷材料通常面临挑战，包括效率低和传热动力学复杂。在这里，我们提出了一种通过正负电热协同效应在单个电场循环内实现高冷却效率的新方法。在宽温度范围 （303 ∼ 443 K） 的三明治异质结薄膜结构中，正 EC 效应 （ΔT _max ∼ 7.54 K） 到负 EC 效应 （ΔT _max ∼ −11.85 K） 的高性能转换在 Ca _0.2 Zr _0.8 O _1.8 /85 %Pb（Mg _1/3 Nb _2/3 ）O ₃ -15 %PbTiO ₃ /Ca _0.2 Zr _0.8 O _1.8 的夹层异质结-薄膜结构中得到了体现。Ca _0.2 Zr _0.8 O _1.8 的这种线性介电死层有助于界面处固定畴的极化反转，并促进层内极性纳米畴的出现，从而能够在单个电场循环中利用正负 EC 协同效应。我们的研究丰富了异质结构界面的功能，为实现高性能芯片级电热薄膜提供了一种独特的方法。