I have prepared PEDOT films on ITO by electropolymerization. I want to compare raman data of PEDOT films at various thicknesses since I observe change in its UV-vis absorption (dedoped PEDOT) spectra with respect to thickness (blue shift on increasing thickness). My films are in doped state and the laser I am using is 514.5 nm. Since doped PEDOT has very less absorption in 500-600 nm region, raman peaks are not very intense (no resonance). The only intense peak is ~1400-1450 nm which is for Cα=Cβ (thiophene ring) symmetric stretch. This peak is affected by change in doping state and conjugation of the ring. In my case I observe broadening of this peak for thinner PEDOT films towards higher wavenumber which is generally observed on increasing doping level. Is anything else can be interpreted from this data?
Thanks!
Regards,
Rekha