Comparison of Optoelectronic Characteristics of Carbon Thin Films Electrodeposited on Silicon and Zinc Substrates

Abstract

Carbon thin films were deposited on Silicon (Si) and Zinc (Zn) substrates by electrodeposition in methanol solution. The role of camphor (C10H16O) incorporation in methanol is studied. In the electrodeposition arrangement Si and Zn substrates were mounted individually on the negative electrodes in camphoric methanol solution. A variable dc voltage source is applied between the electrodes to get better current density in methanol solution during the electrodeposition process. The carbonic thin films deposited on Si and Zn substrates for different percentage of camphor were analyzed by Fourier Transform of Infrared (FTIR) spectroscopic scheme and measurement of optical absorption, transmittance and reflectance by UV-VIS-IR spectroscopic arrangement. Presence of hydrogenated amorphous carbon (a-C: H) bond were observed for the films deposited on Si substrates. The FTIR spectroscopy also indicates existence of both sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> C-H stretch for the films electrodeposited on Si substrate. But there is no clear evidence of the presence of hydrogenated amorphous carbon (a-C: H) bond or sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> C-H stretch for the film deposited on Zn substrate. So Si is more suitable for preparing semiconducting carbon thin films. In the UV-VIS-IR spectroscopy camphor can influence the absorption spectrum of the films deposited on both Si and Zn substrates. In both of the cases increase of camphor, increases the absorption of photon energy. So camphoric methanol solution can influence the optoelectronic properties of carbon thin films, electrodeposited on Si and Zn substrates.