Thermoelectric transport properties of p-type Bi₂Se₃-Sb₂Se₃-In₂ Se₃ high entropy compounds

The introduction of entropy concept into thermoelectric materials recently has attracted broad interest. Herein, we showed the phase diagram of the ternary systems of Bi2Se3-Sb2Se3-In2Se3. Among the high entropy compounds (HECs), we have identified an intrinsic p-type region near our previously reported Bi0.8Sb0.8In0.4Se3 in the phase diagram. We then conducted a systematic investigation in the intrinsic p-type HECs of Bi0.8-xSb0.8In0.4 + xSe3 (x = -0.1 - 0.4), identifying the evolution of real-space lattice structure and reciprocal-space energy band structure. A peak ZT value of 0.68 is achieved in Mn0.03Bi0.67Sb0.8In0.5Se3 at 500 degrees C, a new record in the p-type Bi2Se3 family.