A room-temperature microemulsion synthesis of molecularly capped bismuth telluride nanoparticles with small (average ca. 2.5 nm) diameters is reported (see figure). The use of thioglycolic acid ligands inhibits nanoparticle agglomeration and surface oxidation. Annealing the nanoparticle films to 350 ° C yields a Seebeck coefficient of – 107 μV K–1. The findings are attractive for realizing of high figure of merit thermoelectric materials via nanostructuring control over surface chemistry.