Effects of Au/PEDOT:PSS/P3HT Interface Morphology on the Electrical and Optical Properties of Poly (3-Hexylthiophene)

This study analyzed the interfaces between poly(3-hexylthiophene) (P3HT) on an Au substrate (Au/P3HT) and on Au coated with poly(3,4-ethyldioxythiophene) doped with poly(4-styrenesulfonate) (Au/PEDOT:PSS/P3HT). The different morphologies on the nanostructured Au surface were obtained by applying cyclic potentials using cyclic voltammetry to produce different interfaces in the two systems studied. Under atomic force microscopy (AFM), the number of potential activation cycles was found to produce different roughnesses on the surfaces of the Au electrodes. The interfaces formed were examined by electrochemical impedance spectroscopy (EIS) to identify charge transfer processes for the different segments of the P3HT. The systems were characterized optically by measuring photoluminescence (PL), emission decay time and photoluminescence quantum yield (PLQY). It was observed that the differences in the surface morphologies of the substrates significantly influenced the electrical and optical properties of the P3HT at the interfaces.