A TD-DFT Simulation on Organic Polymer: The Case of PEDOT

Organic semiconductors (OS) are applied in many electronic devices, for instance, OLEDs. The main advantages of these materials are focused in flexibility, high possibilities for structural changes and synthesis. The chemical structure of OS is based on a polymeric chain formed by π conjugated bonds, which act as charge carriers for conductive and optical properties. One of the most investigated polymeric structure is Poly(3,4-ethylenedioxythiophene) (PEDOT) due to its planar molecular structure. To investigate the charge bulk influence formed by \( \uppi \) conjugated bonds on excitation energy and band-gap of PEDOT were performed simulations in PM6, DFT and TD-DFT levels of theory. Consequently, Density of States (DOS) analysis showed an association between intermediary energy levels formed inside monomer band-gap and excitation energy profiles as essential factor to change electronic properties of PEDOT.