Electronic and thermoelectric properties of nonmagnetic inverse Heusler semiconductors Sc2FeSi and Sc2FeGe

Abstract The electronic and thermoelectric properties of two nonmagnetic Hg 2 CuTi-type or called inverse Heusler semiconductors Sc 2 FeSi and Sc 2 FeGe are predicted by using first principles calculations and Boltzmann transport theory. The band gaps of Sc 2 FeSi and Sc 2 FeGe are 0.54 eV and 0.60 eV, respectively. Their zero total magneticmoments both satisfy the M t  =  Z t - 18 while not the M t  =  Z t - 24 rule. The good thermoelectric properties are achieved under the condition of electron doping. At the room temperature 300 K, the peak value of Seebeck coefficient is −592.02 μVK −1 for Sc 2 FeSi, and −609.38 μVK −1 for Sc 2 FeGe by electron doping. The maximum power factor is 48.77(10 14  μW cm −1  K −2  s −1 ) for Sc 2 FeSi and 47.11(10 14  μW cm −1  K −2  s −1 ) for Sc 2 FeGe with electron doping concentration −2.29 × 10 26  m −3 and −2.42 × 10 26  m −3 , respectively, which are close to the power factor of well-known thermoelectric material Bi 2 Te 3 , indicating their potential applying values for thermoelectric devices.