The thermoeletric performance of nanoporous SnSe assembled by hollow cage cluster

Abstract The n-type and p-type thermoelectric property of nanoporous SnSe assembled by hollow cage cluster is studied by First-principles calculations and Boltzmann transport theory. The nanoporous SnSe presents low Shear modulus (3.16 GPa), low Shear sound velocity (925 m/s), low average sound velocity (1203 m/s), low Debye temperature (101K) and large Gruneisen parameter (3.3), which implies that weak Sn-Se atomic interactions and strong anharmonicity of the bonding arrangement. Owing to the cubic structure of nanoporous SnSe, the thermoelectric property along different direction is isotropous. For n type, the optimal ZT at 800K is 2.25, while the highest ZT of p type is 1.81. The strong differences between n type and p type are mainly dominated by the Seebeck coefficient, which is related to the carrier effective mass. This work not only demonstrates the excellent property of nanoporous SnSe, but also provides insights to understand the transport performance of cage structure.