Thermoelectrics
directly converts waste heat into electricity and
is considered a promising means of sustainable energy generation.
While most of the recent advances in the enhancement of the thermoelectric
figure of merit (<i>ZT</i>) resulted from a decrease in
lattice thermal conductivity by nanostructuring, there have been very
few attempts to enhance electrical transport properties, i.e., the
power factor. Here we use nanochemistry to stabilize bulk bismuth
telluride (Bi<sub>2</sub>Te<sub>3</sub>) that violates phase equilibrium,
namely, phase-pure n-type K<sub>0.06</sub>Bi<sub>2</sub>Te<sub>3.18</sub>. Incorporated potassium and tellurium in Bi<sub>2</sub>Te<sub>3</sub> far exceed their solubility limit, inducing simultaneous increase
in the electrical conductivity and the Seebeck coefficient along with
decrease in the thermal conductivity. Consequently, a high power factor
of ∼43 μW cm<sup>–1</sup> K<sup>–2</sup> and a high <i>ZT</i> > 1.1 at 323 K are achieved. Our
current synthetic method can be used to produce a new family of materials
with novel physical and chemical characteristics for various applications
