▎ 摘　　要

Polycrystalline Bi0.4Sb1.6Te3 bulks composited with various graphene content (x = 0, 0.02, 0.05, and 0.1 wt%) were fabricated by high-pressure-and-high-temperature (HPHT) synthesis and high pressure sintering at 4 GPa. The samples by HPHT exhibit the morphology of the large-size well-crystallized lamellar grain. After high pressure sintering, the random distributed grains with smaller size are obtained. Plenty of nanograins and lattice structural disorders are generated by quenching from melt under high pressure. The graphene dispersion reveals inverse effect on thermoelectric properties, due to the competing factors of doping effect and interface scattering. With a low content (