Synthesis of Fluorene-Type Thin Film Under Biphenyl/Methane Plasma Environment

Fluorene-type (C13H10) thin films were synthesized by using the mixture of biphenyl (C12H10) and methane (CH4) plasma. The reactor is a parallel plate installation; upper electrode is connected to 13.56 MHz rf power and lower electrode is grounded. The thin films were deposited by applying a negative bias potential between the substrate and the wall of reactor. The films were investigated by residual gas analysis (RGA), UV–vis spectroscopy, atomic force microscope (AFM) and ellipsometry. They had significant nanostructured properties which were suitable for photovoltaic applications. The conjugation was improved by iodine doping and the optical band gap energy dropped down up to 2.85 eV.