Electronic Structure and Thermoelectric Properties of ZnO Single-Walled Nanotubes and Nanowires

Abstract

Based on ab initio electronic structure calculations and Boltzmann transport theory, the size dependence of thermoelectric properties of ZnO single-walled nanotubes (SWNTs) and nanowires was investigated. There is an optimal carrier concentration yielding the maximum value of ZT at room temperature. The optimal carrier concentration and the maximum value of ZT depend on the diameters and structure of ZnO. The maximum value of ZT for ZnO SWNTs are remarkably higher than that of ZnO nanowires. The 9.60 Å ZnO SWNT possess the highest ZT value, 0.322, which is nearly 3-fold higher than that of the best experimental samples at room temperature.