it depends on the geometry of your TiO2 and DUT. Generally you can get the conductivity from the real part of the impedance spectra. At first the equivalent circuit should be developed or cited from the finished work. Then you can abstract the conductiviy from the equivalent circuit.
Mainly by the help of impedence spectroscopy, one can find the life time of electrons i.e indirectly can know about the recombination rate.
The moment when dye interacts with the TiO2, definitely there will be a change in the position of CB edge. Which causes band bending and also responsible for the generation of Voc. This Voc value depends up on the chemical potentials of the CB and HOMO, LUMO levels of dye molecules.
Really I don't know, Whether one can calculate the CB edge movement or not? Generally people will measure the life time of electron through the impedence spectroscopy.
I will delightful, if you tell me, how to know the band moment by impedence spectroscopy.
Thank you for your response. I posted this question few moths ago. After that I read lots of papers and I got to know we can find the chemical capacitance using impedance spectra. If we draw chemical capacitance Vs applied potential curve, according to the changes in the curve we can get idea of weather CB is moved positively or negatively.
If we measure impedance spectra with some treated DSSCs then we can observe some movement in chemical capacitance respected to untreated DSSCs when the Voc enhancement is caused by CB movement.
If you want to know more I can send some papers related to this.