Characterization of polymeric thin films from isopropanol by PECVD

Polymerized organic thin films were synthesized on a variety of substrates by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique using isopropanol as precursor. Hydrogen peroxide, ammonium hydroxide, and iodine dissolved in isopropanol were used as precursor´s dopants and chlorobenzene as copolymerization precursor. The structural, optical and electrical properties of the films were studied as functions of the dopant type and concentration. The growth rate, refractive index, optical bandgap, chemical structure and resistivity of the films, strongly depend on the concentration and type of added dopant. The AFM microphotographs showed smooth surfaces with RMS roughness less than 10 nm. The optical band-gap values of the films were in the range of 2.6 to 3.26 eV, the resistivity was in the order of 10³–10⁴ ohm-cm. The photoluminescence response of the polymerized films was obtained in the visible region, by exciting with a UV laser.