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 Bi6Cu2Se3.6Cl0.4O6. This work indicates that transition metal element is an effective n-type dopant to enhance the thermoelectric performance of Bi6Cu2Se4O6. The new-type 2D layered oxyselenide Bi6Cu2Se4O6 can be synthesized by intercalating BiCuSeO and Bi2O2Se layers with a 1:2 ratio along the c-axis. Through introducing transition metal elements, a 60 % improvement of peak ZT value (~ 0.16 at 873 K) can be reached in Bi5.9Zr0.1Cu2Se3.6Cl0.4O6. [Display omitted]