An Insight in the Optical Properties of Pristine/Doped Polymers
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
International Conference on the Physics of Semiconductors
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
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 ? and ? 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.
Forschungs-