Rare Earth Element Doping Introduces Pores to Improve Thermoelectric Properties of p-Type Bi0.46Sb1.54Te3

As we all know, the introduction of porous structure into the matrix is a very effective method to enhance the material’s thermoelectric performance. Herein, Er-doped Bi0.46Sb1.54Te3 bulk materials were successfully synthesized by high-energy ball milling and spark plasma sintering. The carrier mobility is enhanced and the carrier concentration is optimized by Er doping, thereby improving the electrical transport properties. Furthermore, the dispersed secondary phase nanoparticles and pores introduced by Er doping provide additional phonon scattering, which leads to the decreased lattice thermal conductivity. Finally, the Erx(Bi0.23Sb0.77)2–xTe3 (x = 0.02) sample shows a maximum ZT value of 1.21 at 350 K, and the average ZT value of 1.17 between 300–400 K is achieved.