In填充下In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y)系热电材料的研究

Thermoelectric Properties of In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y) Filled with In

基于第一性原理,模拟分析了Ni、Te的掺杂对CoSb_(3)热电材料能带和态密度的影响。计算得出其带隙值由0.350 eV减小至0.199 eV,带隙值减小使其热电性能提高。对比各原子的态密度发现,掺杂后样品呈现N型半导体的性质。采用固相反应法,在600℃、40 MPa条件下,通过热压烧结制备了In填充的In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y)系热电材料。结果表明,制备的In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y)系热电材料成分均匀没有杂相。在300 K-800 K的测试温度内,其赛贝克系数、热导率、电导率的变化趋势与预期相吻合,In_(0.3)Co3.5Ni_(0.5)Sb_(11.5)Te_(0.5)热电材料的热导率在700 K时达到最小值为2.4 W·m^(-1)·K^(-1),在750 K时,其热电优值达到了最大值0.62。

Based on the first principles,the effects of Ni and Te doping on the energy band and density of states of CoSb_(3) thermoelectric materials are simulated and analyzed.It is calculated that the band gap value is reduced from 0.350 eV to 0.199 eV,and the reduction of the band gap value improves the thermoelectric performance.Comparing the density of states of each atom,it is found that the doped sample exhibits the properties of an N-type semiconductor.The In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y) series thermoelectric material was prepared by hot-press sintering under the conditions of 600℃and 40 MPa by solid-phase reaction method.The results show that the prepared In_(0.3)Co_(4-x)Ni_(x)Sb_(12-y)Te_(y) thermoelectric material has uniform composition and no impurities.In the test temperature of 300-800 K,the change trend of its Seebeck coefficient,thermal conductivity,and electrical conductivity is consistent with expectations.The thermal conductivity of In_(0.3)Co_(3.5)Ni_(0.5)Sb_(11.5)Te_(0.5) thermoelectric material is 700 K When the minimum value is 2.4 W·m^(-1)·K^(-1),at 750 K,its thermoelectric figure of merit reaches the maximum value of 0.62.