New methods for enhancing ZT value of nanowires

Abstract

We report an important modulating factor, degeneracy, for ZT value enhancement of nanowire. Three approaches to design nanowire of large ZT value by degeneracy effects are proposed: (1) controlling growth direction, (2) increasing the number of near degenerate conduction (valence) subbands induced by quantum confinement and (3) searching for bulk materials with two (or more) sets of near degenerate conduction (or valence) bands to fabricate nanowires. © 2009 IOP Publishing Ltd.