Investigation on halogen‐doped n‐type SnTe thermoelectrics
Changrong Guo, Bingchao Qin, Dongyang Wang, Li‐Dong Zhao
Abstract
Abstract Recent theoretical predictions and experimental findings on the transport properties of n‐type SnTe have triggered extensive researches on this simple binary compound, despite the realization of n‐type SnTe being a great challenge. Herein, Cl as a donor dopant can effectively regulate the position of Fermi level in Sn 0.6 Pb 0.4 Te matrix and successfully achieve the n‐type transport behavior in SnTe. An outstanding power factor of ~ 14.7 µW·cm −1 ·K −2 at 300 K was obtained for Cl‐doped Sn 0.6 Pb 0.4 Te sample. By combining the experimental analysis with theoretical calculations, the transport properties of n‐type SnTe thermoelectrics doped with different halogen dopants (Cl, Br, and I) were then systematically investigated and estimated. The results demonstrated that Br and I had better doping efficiencies compared with Cl, which contributed to the well‐optimized carrier concentrations of ~ 1.03 × 10 19 and ~ 1.11 × 10 19 cm −3 at 300 K, respectively. The improved n‐type carrier concentrations effectively lead to the significant enhancement on the thermoelectric performance of n‐type SnTe. Our study further promoted the experimental progress and deep interpretation of the transport features in n‐type SnTe thermoelectrics. The present results could also be crucial for the development of n‐type counterparts for SnTe‐based thermoelectric devices.