Thermoelectric properties of ZnO nanowires: A first principle research

By means of ab-initio electronic structure calculation and one-dimensional Boltzmann transport equation solution, we investigate the size dependent thermoelectric (TE) properties of n-type ZnO nanowires (NWs) and surface passivation effects. As demonstrated by our calculations, largest figure of merit ZT achievable in thin NWs is larger than that in wide NWs, whereas being restrained by higher demand of n-type doping. Moreover, bare NWs are superior in TE application comparing with the passivated. To compete with conventional TE materials, lattice thermal conductivity of ZnO NWs should be at least 2 orders of magnitude lower than bulk value.

► Thermoelectric properties of ZnO nanowires are investigated theoretically. ► Surface passivation represses thermoelectric properties. ► Small nanowires function better except for high carrier requirement. ► Thermal conductivity of ZnO nanowires should be 100 times lower than bulk value.