Probing transport energies and defect states in organic semiconductors using energy resolved electrochemical impedance spectroscopy

Determining the relative energies of transport states in organic semiconductors is critical to understanding properties electronic devices and designing device stacks. Futhermore, defect are also highly important can greatly impact material performance. Recently, energy-resolved electrochemical impedance spectroscopy (ER-EIS) developed probe both ionization energy (IE) electron affinity (EA) as well sub-bandgap semiconductors. Herein, ER-EIS compared cyclic voltammetry (CV) photoemission spectroscopies for extracting IE EA values, photothermal deflection (PDS) probing polymer molecular The results show that determined better agreement with measurements CV materials. Furthermore, detected by agree features PDS. Surprisingly, regiorandom regioregular poly(3-hexylthiophene) (P3HT) clear bands occur at significantly different energies. In P3HT band near edge occupied while it unoccupied P3HT.