Electrical and Optical Properties of Conductive and Transparent ITO@PMMA Nanocomposites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In this work, nanocomposite films of indium tin oxide (ITO) nanowires in a PMMA matrix were obtained by tape casting. The electrical, optical and morphological properties of films were studied as a function of the amount of wires inserted in the composite, and it was used 1, 2, 5, and 10 wt %. Results confirmed that films transmittance decreases as the concentration of wires increases, attaining a minimum transmittance of 55% for 10 wt % of filler. on the other hand, the electrical resistance of composites was found to decrease by increasing the filler amount and the dc characterization indicate that percolation occurs for about 5 wt % of wires. The morphological studies carried out by TEM were considered to be in good agreement with the electrical results and confirm that for 5% of filler, the ITO nanostructures are in contact with one another inside the polymer. Moreover, we made computational simulation of ID structures in a general matrix and it was found that percolation should occur for about 12 wt %. Although computational results indicate higher amount of wires necessary for percolation than we found experimentally, both results illustrate that using one-dimensional nanostructures as filler in composites enables obtaining percolation for a smaller amount of filler than when using, for instance, nanoparticles. Therefore, the simple processing technique employed here can be used to obtain transparent and conductive composites with several useful applications.