Doping of a Nonconjugated Polymer by an Organic Compound with Two Stable Energy States

We investigate the effect of doping by a small-molecular-weight organic compound phenolphthalein of a non-conjugated polymer polydiphenylenephthalide. Phenolphthalein is known to possess two energy stable states—neutral and charged, as a result of the capture of an excess electron. The morphology of polymer films surfaces observed by atomic force microscopy. The analysis of current–voltage characteristics showed that an increase in the concentration of the dopant leads to an increase in the conductivity. A nontrivial relationship between the increase in the conductivity and charge carrier mobility and the increase in the dopant concentration was found. At the same time, the presence of the dopant does not result in a significant change in the charge carrier concentration.