  By converting waste heat into electricity through the thermoelectric power of
solids without producing greenhouse gas emissions, thermoelectric generators
could be an important part of the solution to today's energy challenge. There
has been a resurgence in the search for new materials for advanced
thermoelectric energy conversion applications. In this paper, we will review
recent efforts on improving thermoelectric efficiency. Particularly, several
novel proof-of-principle approaches such as phonon disorder in
phonon-glasselectron crystals, low dimensionality in nanostructured materials
and charge-spin-orbital degeneracy in strongly correlated systems on
thermoelectric performance will be discussed.
