The coupling of charge carrier and phonon transport limits the application of Ag_(2)Se as a low-toxic near-room-temperature thermoelectric material.Strategies that reduce the thermal conductivity via enhanc-ing the ph...The coupling of charge carrier and phonon transport limits the application of Ag_(2)Se as a low-toxic near-room-temperature thermoelectric material.Strategies that reduce the thermal conductivity via enhanc-ing the phonon scattering usually lead to reduced carrier mobility due to high grain boundary potential barrier.In this study,we developed a cell-membrane-mimic grain boundary engineering strategy for de-coupling the charge carrier and phonon scattering through decorating high-dielectric-constant rutile TiO_(2) at Ag_(2)Se grain boundaries to enable the charge carrier/phonon selective permeability.The nano-sized TiO_(2) with high dielectric permittivity can secure the charge carrier transport by shielding the interfacial Coulomb potential to lower the energy barrier of grain boundaries,rendering an enhanced power factor.Additionally,benefited from the enhanced phonon scattering by TiO_(2) nanoparticles,a significantly de-creased lattice thermal conductivity of~0.20 W m^(-1) K^(-1) and a high zT of~0.97 at 390 K are obtained in the Ag_(2)Se-based nanocomposites.This work demonstrates that such cell-membrane-mimic grain bound-ary engineering strategy may shed light on developing high-performance thermoelectric materials.展开更多
基金National Natural Science Foundation of China(Nos.12074015,52002254,52272160)Sichuan Science and Technology Program(No.2023YFG0220)+3 种基金Fundamental Research Funds for the Central Universities(No.YJ202242)Research Funding from West China School/Hospital of Stomatology Sichuan University,(No.QDJF2022-2)State Key Laboratory for Mechanical Behavior of Materials(No.20232509)fund of the State Key Laboratory of Solidifica-tion Processing in NPU(No.SKLSP202315).
文摘The coupling of charge carrier and phonon transport limits the application of Ag_(2)Se as a low-toxic near-room-temperature thermoelectric material.Strategies that reduce the thermal conductivity via enhanc-ing the phonon scattering usually lead to reduced carrier mobility due to high grain boundary potential barrier.In this study,we developed a cell-membrane-mimic grain boundary engineering strategy for de-coupling the charge carrier and phonon scattering through decorating high-dielectric-constant rutile TiO_(2) at Ag_(2)Se grain boundaries to enable the charge carrier/phonon selective permeability.The nano-sized TiO_(2) with high dielectric permittivity can secure the charge carrier transport by shielding the interfacial Coulomb potential to lower the energy barrier of grain boundaries,rendering an enhanced power factor.Additionally,benefited from the enhanced phonon scattering by TiO_(2) nanoparticles,a significantly de-creased lattice thermal conductivity of~0.20 W m^(-1) K^(-1) and a high zT of~0.97 at 390 K are obtained in the Ag_(2)Se-based nanocomposites.This work demonstrates that such cell-membrane-mimic grain bound-ary engineering strategy may shed light on developing high-performance thermoelectric materials.
