Enhancing thermoelectric performance of n-type Bi6Cu2Se4O6 through introducing transition metal elements

Compared with p-type oxyselenide thermoelectric material, the corresponding n-type material research progress is slow. In this work, combining low thermal conductivity of BiCuSeO and high electron carrier concentration of n-type Bi₂O₂Se, a new-type two-dimensional layered oxyselenide Bi₆Cu₂Se₄O₆ was synthesized. Through increasing electron carrier concentration via introducing transition metal elements (Ti, Zr, Ce), the electrical transport properties were enhanced and the peak ZT value ~ 0.16 at 873 K was obtained, which is 60 % higher than that in Bi₆Cu₂Se_3.6Cl_0.4O₆. This work indicates that transition metal element is an effective n-type dopant to enhance the thermoelectric performance of Bi₆Cu₂Se₄O₆.