As an eco-friendly thermoelectric material,Sn Te has attracted extensive attention.In this study,we use a stepwise strategy to enhance the thermoelectric performance of Sn Te.Firstly,Ag Cl is doped into Sn Te to reali...As an eco-friendly thermoelectric material,Sn Te has attracted extensive attention.In this study,we use a stepwise strategy to enhance the thermoelectric performance of Sn Te.Firstly,Ag Cl is doped into Sn Te to realize band convergence and enlarge the band gap of Ag Cl-doped Sn Te.Ag Cl-doping also induces dense point defects,strengthens the phonon scattering,and reduces the lattice thermal conductivity.Secondly,Sb is alloyed into Ag Cl-doped Sn Te to further optimize the carrier concentration and simultaneously reduce the lattice thermal conductivity,leading to improved thermoelectric dimensionless figure of merit,ZT.Finally,(Sn_(0.81)Sb_(0.19)Te)_(0.93)(Ag Cl)_(0.07)has approached the ZT value as high as~0.87 at 773 K,which is 272%higher than that of pristine Sn Te.This study indicates that stepwise Ag Cl-doping and Sb-alloying can significantly improve thermoelectric performance of Sn Te due to synergistic band engineering,carrier concentration optimization and defect engineering.展开更多
Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying ...Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51871240)。
文摘As an eco-friendly thermoelectric material,Sn Te has attracted extensive attention.In this study,we use a stepwise strategy to enhance the thermoelectric performance of Sn Te.Firstly,Ag Cl is doped into Sn Te to realize band convergence and enlarge the band gap of Ag Cl-doped Sn Te.Ag Cl-doping also induces dense point defects,strengthens the phonon scattering,and reduces the lattice thermal conductivity.Secondly,Sb is alloyed into Ag Cl-doped Sn Te to further optimize the carrier concentration and simultaneously reduce the lattice thermal conductivity,leading to improved thermoelectric dimensionless figure of merit,ZT.Finally,(Sn_(0.81)Sb_(0.19)Te)_(0.93)(Ag Cl)_(0.07)has approached the ZT value as high as~0.87 at 773 K,which is 272%higher than that of pristine Sn Te.This study indicates that stepwise Ag Cl-doping and Sb-alloying can significantly improve thermoelectric performance of Sn Te due to synergistic band engineering,carrier concentration optimization and defect engineering.
基金financially supported by the National Natural Science Foundation of China (No. 51871240)。
文摘Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.
