title: Optimizing the Dopant and Carrier Concentration of Ca5Al2Sb6 for High Thermoelectric Efficiency.
abstract: The effects of doping on the transport properties of Ca5Al2Sb6 are investigated using first-principles electronic structure methods and Boltzmann transport theory. The calculated results show that a maximum ZT value of 1.45 is achieved with an optimum carrier concentration at 1000 K. However, experimental studies have shown that the maximum ZT value is no more than 1 at 1000 K. By comparing the calculated Seebeck coefficient with experimental values, we find that the low dopant solubility in this material is not conductive to achieve the optimum carrier concentration, leading a smaller experimental value of the maximum ZT. Interestingly, the calculated dopant formation energies suggest that optimum carrier concentrations can be achieved when the dopants and Sb atoms have similar electronic configurations. Therefore, it might be possible to achieve a maximum ZT value of 1.45 at 1000 K with suitable dopants. These results provide a valuable theoretical guidance for the synthesis of high-performance bulk thermoelectric materials through dopants optimization.
authors.affiliation: Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 75004, People's Republic of China.|Department of Physics, International Center for Quantum and Molecular Structures, and Materials Genome Institute, Shanghai University, Shanghai 200444, China.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 75004, People's Republic of China.
authors.forename: Guangbiao
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 75004, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 75004, People's Republic of China.
authors.forename: Chengxiao
authors.initials: C
authors.lastname: Peng
authors.affiliation: Department of Physics, International Center for Quantum and Molecular Structures, and Materials Genome Institute, Shanghai University, Shanghai 200444, China.|Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
authors.forename: Peihong
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 75004, People's Republic of China.
authors.forename: Yuanxu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physics, International Center for Quantum and Molecular Structures, and Materials Genome Institute, Shanghai University, Shanghai 200444, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ren