Spectroscopic ellipsometry measurements of conductive graft copolymer thin films in gaseous environment

Authors: P. KAŁUŻYŃSKI1*, Z. OPILSKI1, K. GWOREK1, A. STOLARCZYK2
1)Department of Optoelectronics, Silesian University of Technology, Krzywoustego 2 Str, Gliwice, Poland
2)Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 9 Strzody St., 44-100 Gliwice, Poland *Mail: piotr.kaluzynski@polsl.pl

Abstract:
In micro optoelectronics devices, such as gas sensors or photovoltaic devices, the use of modern, easily processable materials plays a key role and attracts the attention of scientists from around the world. Commonly used polymer materials such as polyaniline, polytiophene, polypyrrole are poor processability (solubility, durability, adhesion), and therefore researchers are focused in finding polymers with better processability. By grafting synthetic polymers with functional groups, new polymers can be obtained, that will be easily processable and can also be easily dissolved in popular solvents (chloroform, toluene), which reduces fabrication cost. Moreover, grafting synthetic polymers also increases their stability and this novel comb-like graft copolymer can be also used as a gas sensing layer for gas sensing structures (e.g. polymer thin film transistors).
This work presents an investigation on the influence of different factors on conductive graft comb copolymer polymethylsiloxane (PMS) with poly(3-hexyltiophene) (P3HT) and poly(ethylene) glycol as functional side groups. The analysed factors that influenced the parameters of the layers were temperature and different gas atmosphere (N2, NO2). Samples were by spectroscopic ellipsometry under the influence of a gas atmosphere. Moreover, morphology (sample roughness) and optical properties (transmittance, absorbance) were measured of obtained thin films deposited on glass substrate using spin coating method.

Acknowledgements: The presented work was partially sponsored by the Polish National Science Centre “NCN” within the grant 2016/23/B/ST5/03103. Syntheses of graft combcopolymer materials were performed with the support from the Foundation for Polish Science grant POMOST 2011-3/8. The work was partially sponsored by the Faculty of Electrical Engineering of Silesian University of Technology within the grant BKM/567/RE4/2017.