Characterization of an amorphous indium tin oxide (ITO) film on a polylactic acid (PLA) substrate

The study presents the deposition of nanostructured indium tin oxide thin films with thicknesses of 10, 30 and 50 nm on the polylactic acid (PLA) substrate by sputtering at 30∘C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$30{^{\circ }}\hbox {C}$$\end{document}. The absence of ITO peaks on the X-ray diffraction patterns confirms the amorphous state of ITO films and the X-ray photoelectron spectroscopy spectrum validates the deposition of ITO films on the PLA substrate. The results of atomic force microscopy of films exhibit variation in the average roughness of 0.3–1.5 nm when the thickness is increased. It was examined that optical transmission is dependent on the thickness of films which varies from 78 to 87% in the visible spectrum of 400–700 nm and the energy band gap varies from 3.95 to 4.02 eV. The films exhibit the low sheet resistance which is due to the formation of oxygen vacancies and dangling bonds. An increase in transmittance enhances the FOM of the ITO films on the PLA substrate.