An Insight in the Optical Properties of Pristine/Doped Polymers

Description

New generations of solution processable materials have been developed in the last years. These materials were found to have desirable photophysical properties, which can be easily modified by doping. Usually spectroscopy is performed in UVVIS / NIR based on transmission / reflection measurements, which are both rather insensitive for the accurate determination of optical properties of thin layers. Also for the investigation of the changes in spectra, e.g. when comparing spectra of doped samples to undoped ones, the strong transmission / reflection of the substrate can be detrimental. In order to assign optical properties due to doping the variation of the complex dielectric function as a function of doping has to be measured using ellipsometry. We present an application of NIR-UV-Vis ellipsometry for studying the optical properties of conducting polymers. The ellipsometric values ψ and Δ were measured as a function of wavelength, and partially in situ in an electrochemical cell as a function of the applied potential. The obtained data were modeled and the the real and imaginary part of the dielectric function were determined. Upon doping, the appearance of new infrared activated vibrations (IRAVs) and polaron induced broadband absorptions in the complex dielectric/complex refractive index function have been found, giving an insight the physical properties of the created radicals.

Period	11 Aug 2014
Event title	International Conference on the Physics of Semiconductors
Event type	Conference
Location	United StatesShow on map