In thermoelectricity,the inherent coupling between electrical conductivity and Seebeck coefficient represents a fundamental challenge in thermoelectric materials development.Herein,we present a unique pressure-tuning ...In thermoelectricity,the inherent coupling between electrical conductivity and Seebeck coefficient represents a fundamental challenge in thermoelectric materials development.Herein,we present a unique pressure-tuning strategy using compressible layered 2H-MoTe2,achieving an effective decoupling between the electrical conductivity and Seebeck coefficient.The applied pressure simultaneously induces two complementary effects:(1)bandgap reduction that moderately enhances carrier concentration to improve the electrical conductivity,and(2)band convergence that dramatically increases density-of-states effective mass to boost the Seebeck coefficient.This dual mechanism yields an extraordinary 18.5-fold enhancement in the average power factor.First-principles calculations and Boltzmann transport modeling precisely reproduce the experimental observations,validating this pressure-induced decoupling mechanism.The pressure-tuning mechanism provides a feasible and effective strategy for breaking through the optimization limits of the power factor,facilitating the design of high-performance thermoelectric materials.展开更多
Heat conduction in oxygen probe was analyzed by means of non-steady state method and measured using 'double probe' arrangement. The results showed that during the response process the thermal emf was decreased...Heat conduction in oxygen probe was analyzed by means of non-steady state method and measured using 'double probe' arrangement. The results showed that during the response process the thermal emf was decreased exponentially with the time and in case of low oxygen level the Seebeck coefficient and thermal conductivity of solid electrolyte agreed well with those in literatures.展开更多
Spin currents,which are excited in indium tin oxide(ITO)/yttrium iron garnet(YIG)by the methods of spin pumping and spin Seebeck effect,are investigated through the inverse spin Hall effect(ISHE).It is demonstrated th...Spin currents,which are excited in indium tin oxide(ITO)/yttrium iron garnet(YIG)by the methods of spin pumping and spin Seebeck effect,are investigated through the inverse spin Hall effect(ISHE).It is demonstrated that the ISHE voltage can be generated in ITO by spin pumping under both in-plane and out-of-plane magnetization configurations.Moreover,it is observed that the enhancement of spin Hall angle and interfacial spin mixing conductance can be achieved by an appropriate annealing process.However,the ISHE voltage is hardly seen in the presence of a longitudinal temperature gradient.The absence of the longitudinal spin Seebeck effect can be ascribed to the almost equal thermal conductivity of ITO and YIG and specific interface structure,or to the large negative temperature dependent spin mixing conductance.展开更多
The thermoelectric performance of free-standing poly(3,4-ethylenedioythiophene):poly(styrenesulfonate)(PEDOT:PSS)thin films deposited from aqueous dispersion treated by different concentrations of urea are investigate...The thermoelectric performance of free-standing poly(3,4-ethylenedioythiophene):poly(styrenesulfonate)(PEDOT:PSS)thin films deposited from aqueous dispersion treated by different concentrations of urea are investigated in detail.The electrical conductivity,Seebeck coefficient and power factor of PEDOT:PSS films versus temperature are determined,respectively.It is found that both the electrical conductivity and Seebeck coefficient of PEDOT:PSS films are enhanced after treatment with urea.Conductivity could be enhanced from 8.16 to 63.13S-cm^(-1),the Seebeck coefficient is increased from 14.47 to 20.7μV.K^(-1)and the power factor is rises to 2.7μW.m^(-1)K^(-2)at 300K.展开更多
基金supported by the Science and Technology Development Project of Jilin Province(Grant No.SKL202402004)the Program for the Development of Science and Technology of Jilin Province(Grant No.YDZJ202201ZYTS308)+1 种基金the Open Research Fund of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,Jilin University(Grant Nos.202216 and 2022-23)the National Natural Science Foundation of China(Grant No.12350410372)。
文摘In thermoelectricity,the inherent coupling between electrical conductivity and Seebeck coefficient represents a fundamental challenge in thermoelectric materials development.Herein,we present a unique pressure-tuning strategy using compressible layered 2H-MoTe2,achieving an effective decoupling between the electrical conductivity and Seebeck coefficient.The applied pressure simultaneously induces two complementary effects:(1)bandgap reduction that moderately enhances carrier concentration to improve the electrical conductivity,and(2)band convergence that dramatically increases density-of-states effective mass to boost the Seebeck coefficient.This dual mechanism yields an extraordinary 18.5-fold enhancement in the average power factor.First-principles calculations and Boltzmann transport modeling precisely reproduce the experimental observations,validating this pressure-induced decoupling mechanism.The pressure-tuning mechanism provides a feasible and effective strategy for breaking through the optimization limits of the power factor,facilitating the design of high-performance thermoelectric materials.
文摘Heat conduction in oxygen probe was analyzed by means of non-steady state method and measured using 'double probe' arrangement. The results showed that during the response process the thermal emf was decreased exponentially with the time and in case of low oxygen level the Seebeck coefficient and thermal conductivity of solid electrolyte agreed well with those in literatures.
基金Project supported by the National Key Basic Research Project of China(Grant No.2016YFA0300600)Chinese Academy of Sciences(Grant No.KJCX2-YW-W24)+1 种基金the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11604375)the Laboratory of Microfabrication of Institute of Physics,Chinese Academy of Sciences
文摘Spin currents,which are excited in indium tin oxide(ITO)/yttrium iron garnet(YIG)by the methods of spin pumping and spin Seebeck effect,are investigated through the inverse spin Hall effect(ISHE).It is demonstrated that the ISHE voltage can be generated in ITO by spin pumping under both in-plane and out-of-plane magnetization configurations.Moreover,it is observed that the enhancement of spin Hall angle and interfacial spin mixing conductance can be achieved by an appropriate annealing process.However,the ISHE voltage is hardly seen in the presence of a longitudinal temperature gradient.The absence of the longitudinal spin Seebeck effect can be ascribed to the almost equal thermal conductivity of ITO and YIG and specific interface structure,or to the large negative temperature dependent spin mixing conductance.
基金Supported by the National Natural Science Foundation of China under Grant Nos 5093002 and 60767001.
文摘The thermoelectric performance of free-standing poly(3,4-ethylenedioythiophene):poly(styrenesulfonate)(PEDOT:PSS)thin films deposited from aqueous dispersion treated by different concentrations of urea are investigated in detail.The electrical conductivity,Seebeck coefficient and power factor of PEDOT:PSS films versus temperature are determined,respectively.It is found that both the electrical conductivity and Seebeck coefficient of PEDOT:PSS films are enhanced after treatment with urea.Conductivity could be enhanced from 8.16 to 63.13S-cm^(-1),the Seebeck coefficient is increased from 14.47 to 20.7μV.K^(-1)and the power factor is rises to 2.7μW.m^(-1)K^(-2)at 300K.
