Effects of Zr substitution on structure and thermoelectric properties of Bi2O2Se

In this study, the facile synthesis method of Bi 2 − x Zr x O 2 Se ( x  = 0, 0.02, 0.04, and 0.06) ceramics using a combining the high-energy ball milling and cold pressing was reported. The effects of zirconium (Zr) doping on the microstructure and thermoelectric properties of Bi 2 O 2 Se were systematically investigated. The results indicate that the powder samples were synthesized as a single phase with no impurities. With increasing Zr content, conductivity increased from 13.49 S to 34.91 S cm −1 at 773 K. The thermal conductivity of Bi 1.98 Zr 0.02 O 2 Se was also reduced to 0.51 W m −1  K −1 . The maximum power factor (PF) value of the Bi 1.96 Zr 0.04 O 2 Se sample was 186 μW m −1  K −2 at 773 K. A peak ZT of around 0.27 was achieved for the Bi 1.96 Zr 0.04 O 2 Se sample, which is approximately 2.4 times greater than that of un-doped one (∼0.11). The results indicate that Zr-doping significantly improves the thermoelectric properties of the Bi 2 O 2 Se system.