Electron Transfer and Trapping in Natural p–n Bipolar Polymer-Based Bilayer Films

Cyclic voltammetry and spectroelectrochemistry were separately employed to study and observe the electron transfer and trapping behavior between two bipolar polymers synthesized by the cyclic voltammetry method. The poly(DNTD) and poly(Cl 4 DPTD) were pair-sequentially electropolymerized on a Pt disk electrode and indium tin oxide (ITO) transparent electrodes for electron-transfer and electron trapping studies, respectively. Interestingly, the electrochemical responses of the bilayers at negative potentials vs Ag/AgCl were observed to depend on the bilayer assembly sequence. The lowest unoccupied molecular orbital (LUMO) difference between poly(DNTD) and poly(Cl 4 DPTD) provides a large enough electronic barrier to trap the electrons between the n-type units in the polymers.