In this work,dielectric ultracapacitors were designed and fabricated using a combination of phase boundary and nanograin strategies.These ultracapacitors are based on submicron-thick Ba(Zr_(0.2)Ti_(0.8))O_(3) ferroele...In this work,dielectric ultracapacitors were designed and fabricated using a combination of phase boundary and nanograin strategies.These ultracapacitors are based on submicron-thick Ba(Zr_(0.2)Ti_(0.8))O_(3) ferroelectric films sputterdeposited on Si at 500℃.With a composition near a polymorphic phase boundary(PPB),a compressive strain,and a high nucleation rate due to the lowered deposition temperature,these films exhibit a columnar nanograined microstructure with gradient phases along the growth direction.Such a microstructure presents three-dimensional polarization inhomogeneities on the nanoscale,thereby significantly delaying the saturation of the overall electric polarization.Consequently,a pseudolinear,ultraslim polarization(P)-electric field(E)hysteresis loop was obtained,featuring a high maximum applicable electric field(~5.7 MV/cm),low remnant polarization(~5.2μC/cm^(2))and high maximum polarization(~92.1μC/cm^(2)).This P-E loop corresponds to a high recyclable energy density(Wrec~208 J/cm^(3))and charge‒discharge efficiency(~88%).An indepth electron microscopy study revealed that the gradient ferroelectric phases consisted of tetragonal(T)and rhombohedral(R)polymorphs along the growth direction of the film.The T-rich phase is abundant near the bottom of the film and gradually transforms into the R-rich phase near the surface.These films also exhibited a high Curie temperature of~460℃and stable capacitive energy storage up to 200℃.These results suggest a feasible pathway for the design and fabrication of high-performance dielectric film capacitors.展开更多
基金the financial support from the Natural Science Foundation of Shandong Province(Nos.ZR2022ZD39,ZR2022ME031,ZR2023QB119,ZR2023QE138,ZR2020QE042,and ZR2022QB138)the National Natural Science Foundation of China(No.52002192)+3 种基金the Science,Education and Industry Integration Pilot Projects of Qilu University of Technology(Shandong Academy of Sciences)(Nos.2022GH018,2023PX062,and 2023PX041)the Training Plan Project of Qilu University of Technology(Nos.2023RCKY093 and 2023RCKY095)the support from the Jinan City Science and Technology Bureau(No.2021GXRC055)the Education Department of Hunan Province/Xiangtan University(No.KZ0807969)。
文摘In this work,dielectric ultracapacitors were designed and fabricated using a combination of phase boundary and nanograin strategies.These ultracapacitors are based on submicron-thick Ba(Zr_(0.2)Ti_(0.8))O_(3) ferroelectric films sputterdeposited on Si at 500℃.With a composition near a polymorphic phase boundary(PPB),a compressive strain,and a high nucleation rate due to the lowered deposition temperature,these films exhibit a columnar nanograined microstructure with gradient phases along the growth direction.Such a microstructure presents three-dimensional polarization inhomogeneities on the nanoscale,thereby significantly delaying the saturation of the overall electric polarization.Consequently,a pseudolinear,ultraslim polarization(P)-electric field(E)hysteresis loop was obtained,featuring a high maximum applicable electric field(~5.7 MV/cm),low remnant polarization(~5.2μC/cm^(2))and high maximum polarization(~92.1μC/cm^(2)).This P-E loop corresponds to a high recyclable energy density(Wrec~208 J/cm^(3))and charge‒discharge efficiency(~88%).An indepth electron microscopy study revealed that the gradient ferroelectric phases consisted of tetragonal(T)and rhombohedral(R)polymorphs along the growth direction of the film.The T-rich phase is abundant near the bottom of the film and gradually transforms into the R-rich phase near the surface.These films also exhibited a high Curie temperature of~460℃and stable capacitive energy storage up to 200℃.These results suggest a feasible pathway for the design and fabrication of high-performance dielectric film capacitors.
