Breaking the tradeoff among thermoelectric parameters by multi composite of porosity and CNT in AZO films

Abstract

Multi-nanocomposite is an effective method to achieve high thermoelectric (TE) performance by breaking the tradeoff among three TE parameters. This paper presents a comparative study of incorporated carbon nanotube (CNT)/Au in evaporated porous Al-doped ZnO (AZO) films. The effect of the nanocomposite interface on scattering of carriers and phonons is used to independently tune thermal conductivity and power factor in the multi-nanocomposite AZO films. This breaks the tradeoff and improves the figure of merit (ZT) of the film. Moreover, the temperature gradient retains in the out-of-plane of the films. These make the AZO film composited CNT and porosity have higher output power than that of the non-porous films. This provides a simple method for the low-dimension film to increase the TE properties through breaking the tradeoff and makes the TE materials suitable for efficient harvesting in low-grade waste heat.