  Thermoelectric materials, enabling the directing conversion between heat and
electricity, are one of the promising candidates for overcoming environmental
pollution and the upcoming energy shortage caused by the over-consumption of
fossil fuels. Bi2Te3-based alloys are the classical thermoelectric materials
working near room temperature. Due to the intensive theoretical investigations
and experimental demonstrations, significant progress has been achieved to
enhance the thermoelectric performance of Bi2Te3-based thermoelectric
materials. In this review, we first explored the fundamentals of thermoelectric
effect and derived the equations for thermoelectric properties. On this basis,
we studied the effect of material parameters on thermoelectric properties.
Then, we analyzed the features of Bi2Te3-based thermoelectric materials,
including the lattice defects, anisotropic behavior and the strong bipolar
conduction at relatively high temperature. Then we accordingly summarized the
strategies for enhancing the thermoelectric performance, including point defect
engineering, texture alignment, and band gap enlargement. Moreover, we
highlighted the progress in decreasing thermal conductivity using
nanostructures fabricated by solution grown method, ball milling, and melt
spinning. Lastly, we employed modeling analysis to uncover the principles of
anisotropy behavior and the achieved enhancement in Bi2Te3, which will
enlighten the enhancement of thermoelectric performance in broader materials.
