Realizing high thermoelectric performance in n-type highly distorted Sb-doped SnSe microplates via tuning high electron concentration and inducing intensive crystal defects

Abstract

In this study, a record high figure of merit (ZT) of ≈1.1 at 773 K is reported in n‐type highly distorted Sb‐doped SnSe microplates via a facile solvothermal method. The pellets sintered from the Sb‐doped SnSe microplates show a high power factor of ≈2.4 µW cm−1 K−2 and an ultralow thermal conductivity of ≈0.17 W m−1 K−1 at 773 K, leading a record high ZT. Such a high power factor is attributed to a high electron concentration of 3.94 × 1019 cm−3 via Sb‐enabled electron doping, and the ultralow thermal conductivity derives from the enhanced phonon scattering at intensive crystal defects, including severe lattice distortions, dislocations, and lattice bent, observed by detailed structural characterizations. This study fills in the gaps of fundamental doping mechanisms of Sb in SnSe system, and provides a new perspective to achieve high thermoelectric performance in n‐type polycrystalline SnSe