Thermoelectric properties of Pb and Na dual doped BiCuSeO

BiCuSeO is a promising thermoelectric material not only because of its good thermoelectric properties, but also earth abundant constituents. In this report, Pb and Na have been simultaneously doped at the Bi site of BiCuSeO. Doping Pb is beneficial for the Seebeck coefficient whereas doping Na maintains the hole mobility. Both the dopants increase the carrier concentration and reduce the thermal conductivity by point-defect scattering. The samples with nominal composition Bi0.985-xNa0.015PbxCuSeO ( x=0.00, 0.04, 0.06 and 0.08) were prepared using two-step solid-state synthesis. The X-ray diffraction pattern reveals a small amount of Bi2O2.5 phase (