High entropy stabilization and band engineering driven high figure of merit in nanostructured PbSn0.875TeSeBi0.125 alloy

The facile synthesis of nanocrystalline lead tin tellurium selenium (PbSnTeSe) high entropy alloy (HEA) doped with Bi by mechanical alloying (MA) (5 hrs) and spark plasma sintering (SPS) (11 min) is reported. The first principle approach prediction and experimental validation confess the strong implications of enhanced configurational entropy and band engineering phenomena in nanostructured PbSn0.875TeSeBi0.125 HEA. The approach enables the superior power factor (12.74×10−4 ​W/mK2) and ultralow thermal conductivity (0.814 ​W/mK) to explore the superior figure of merit, ZT ​= ​0.71 in PbSn0.875TeSeBi0.125 HEA and compatibility factor (CF) of 3.10 ​at 623 ​K.This shows the applaudable enhancement of 154% in ZT than pristine PbSnTeSe HEA (ZT ​= ​0.46).