Point defect-assisted doping mechanism and related thermoelectric transport properties in Pb-doped BiCuOTe

Abstract

In this article we report point defect-assisted doping mechanism and related thermoelectric transport properties in Pb-doped BiCuOTe compounds. The substitution of trivalent Bi³⁺ with divalent Pb²⁺ led to the generation of more than one hole per single Pb atom. The origin of the extra charge carrier was discussed in terms of the formation energy of p-type native point defects, and it could be evidenced by the density functional theory calculations. Related charge transport properties indicated that control of the native point defect is critical to achieve high thermoelectric performance in BiCuOTe material system.