In situ spectroelectrochemical study of positively and negatively charged states in a donor/acceptor EDOT/benzotriazole-based polymer

Positively and negatively charged states in cPBEBT, which consists of EDOT/benzotriazole/EDOT as the building block, are studied using CV, in situ UV-Vis, and FTIR-ATR spectroscopy. The results show that cPBEBT is an ambipolar D-A-type polymer capable of conducting both holes and electrons. The injected positive and negative charges are distributed over the whole polymer backbone, which is proven by in situ FTIR-ATR where spectral signatures associated with the benzotriazole unit are observed in both p- and n-doped cPBEBT. HOMO and LUMO values obtained from CV and FTIR-ATR experiments during oxidation and reduction are compared. cPBEBT is an example of the D-A approach towards the improvement of the electronic properties of the resultant polymer. cPBEBT is a D-A-type polymer consisting of EDOT/benzotriazole/EDOT building blocks. It can be p- and n-doped reversibly, as shown by different in situ spectroelectrochemical techniques. There are only a few materials that can be reversibly both p- and n-doped, which is a very interesting property and makes cPBEBT very attractive for optoelectronic applications.