Determination of the Optical Properties of ppTh Nanostructured Films Obtained by RF Plasma Polymerisation Technique

In this study, it is aimed to obtain plasma polymerized Thiophene (ppTh) thin films by Radio Frequency (RF) plasma polymerization technique and to determine optical, chemical and morphological properties of these films. ppTh thin films were fabricated at 25, 50, 75 and 100 W RF power, 15 minutes coating duration and 500 mTorr base pressure. ppTh thin films were analyzed by Scanning Electron Microscopy (SEM), FTIR and Uv-Vis spectroscopy. Functional groups of thin films were determined by FTIR spectroscopy, and it was investigated how coating parameters affect the chemical structure of these films. Optical properties such as absorbance, transmittance and optical band gap were determined by Uv-Vis spectroscopy. The optical band gaps of the ppTh thin films were determined to be 2.97 eV, 3.13 eV, 3.17 eV and 3.68 eV with increasing RF power, respectively. In addition, all thin films were highly transparent in the visible region (500 nm), and this transparency tended to increase with increasing RF power. SEM analysis showed that the thin films had nanosphere structure and the radius of these spheres was about 90 nm.