Electrochemically- and Photoinduced Infrared Bands in PPV: A ComparativeStudy

Results of in situ Fourier transform infrared attenuated total reflection (FTIR ATR) spectroscopy during electrochemical oxidation processes (electrochemically induced doping) as well as by photoinduced infrared absorption spectroscopy (photoinduced doping) of polyparaphenylenevinylene (PPV) are presented. Infrared active vibrational (IRAV) bands in the lower energy part of the infrared spectrum and infrared absorption due to electronic transitions at higher energies are observed and compared. The electrochemical doping of PPV occurs in two potential regions. In the "low doping" region, the difference spectra obtained by in situ FTIR ATR spectroscopy are similar to spectra obtained by chemical doping. In the "high doping" region, the spectral behavior is different to the "low doping" region and shows a higher similarity to the photoinduced absorption spectrum.