New free-standing and flexible PVA/Carbon quantum dots (CQDs) nanocomposite films with promising power factor and thermoelectric power applications

摘要

Recently, flexible nanocomposite thermoelectric materials, especially inorganic polymers, have attracted increasing attention. In this paper, we successfully fabricated novel P-type thermoelectric PVA/CQDs nanocomposite films through the solution casting technique. Zero-dimension CQDs nanoparticles were first prepared by the microwave heating method and then injected into the PVA matrix to achieve free-standing films. PVA/CQDs nanocomposite films were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermoelectric properties such as electrical conductivity, Seebeck coefficient, and thermal conductivity of the prepared films were studied. XRD patterns showed the effect of CQDs nanoparticles on the crystallinity of the nanocomposite. The average size of CQDs nanoparticles was found to be 4.5 nm. The PVA/CQDs nanocomposite has a high conductivity (30.3 S/cm), an excellent power factor (15.2 mu W/m K-2), and a high figure of merit (0.005) with CQDs content of 2 wt%. Finally, these nanocomposites have a promising potential application in thermoelectric devices because they are economical and easy to scale up.