| Autor: |
Shirsath SE; School of Materials Science and Engineering , University of New South Wales , Sydney , New South Wales 2052 , Australia., Cazorla C; School of Materials Science and Engineering , University of New South Wales , Sydney , New South Wales 2052 , Australia., Lu T; Research School of Chemistry , The Australian National University , Canberra , Australian Capital Territory 2601 , Australia., Zhang L; School of Materials Science and Engineering , University of New South Wales , Sydney , New South Wales 2052 , Australia., Tay YY; Facility for Analysis, Characterization, Testing and Simulation and School of Materials Science and Engineering , Nanyang Technological University , 50 Nanyang Avenue , 639798 Singapore., Lou X; Multi-disciplinary Materials Research Centre, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials , Xi'an Jiaotong University , Xi'an 710049 , China., Liu Y; Research School of Chemistry , The Australian National University , Canberra , Australian Capital Territory 2601 , Australia., Li S; School of Materials Science and Engineering , University of New South Wales , Sydney , New South Wales 2052 , Australia., Wang D; School of Materials Science and Engineering , University of New South Wales , Sydney , New South Wales 2052 , Australia. |
| Abstrakt: |
Conventional refrigeration methods based on compression-expansion cycles of greenhouse gases are environmentally threatening and cannot be miniaturized. Electrocaloric effects driven by electric fields are especially well suited for implementation of built-in cooling in portable electronic devices. However, most known electrocaloric materials present poor cooling performances near room temperature, contain toxic substances, and require high electric fields. Here, we show that lead-free ferroelectric thin-film bilayers composed of (Bi 0.5 Na 0.5 )TiO 3 -BaTiO 3 (BNBT) and Ba(Zr 0.2 Ti 0.8 )O 3 -(Ba 0.7 Ca 0.3 )TiO 3 (BCZT) display unprecedentedly large electrocaloric effects of ∼23 K near room temperature under moderate electric bias. The giant electrocaloric effect observed in BNBT/BCZT bilayers, which largely surpasses the sum of the individual caloric responses measured in BNBT and BCZT, is originated from the presence of compositional bound charges at their interface. Our discovery of interface charge-induced giant electrocaloric effects indicates that multilayered oxide heterostructures hold tremendous promise for developing highly efficient and scalable solid-state cooling applications. |
