The recent discovery of high thermoelectric performance in Mg3Sb2 has been critically enabled by the success in n-type doping of this material, which is achieved under Mg-rich growth conditions, typically with chalcogens (Se, Te) as extrinsic dopants. Using first-principles defect calculations, we previously predicted that higher electron concentrations (∼1020 cm−3) can be achieved in Mg3Sb2 by doping with La instead of Se or Te. Subsequent experiments showed that free electron concentration in La-doped Mg3Sb2−xBix indeed exceeds those in the Te-doped material. Herein, we further investigate n-type doping of Mg3Sb2 and predict that, in addition to La, other group-3 elements (Sc, Y) are also effective as n-type dopants; Y is as good as La while Sc slightly less. Overall, we find that doping with any group-3 elements should lead to higher free electron concentrations than doping with chalcogens.
@article{arxiv.1810.08321,
title = {Effective $n$-type Doping of Mg$_3$Sb$_2$ with Group-3 Elements},
author = {Prashun Gorai and Eric S. Toberer and Vladan Stevanovic},
journal= {arXiv preprint arXiv:1810.08321},
year = {2019}
}