Determination of the dynamic dielectric function of PEDOT:PSS from the visible to the near-infrared region

Abstract

Poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) thin films with tunable optical properties have shown great potential in optoelectronic device applications. Here, we present a new hybrid technology for accurately determining the dielectric properties of PEDOT:PSS films upon bias. Using electrochemical method together with numerical simulation of ellipsometry measurement, significant variations of the dielectric functions in a wide spectral range (400-1690 nm) under external voltage excitation are found. The ordinary dielectric constants increase under external voltage excitation, while the extraordinary dielectric constants remain unchanged. The simulation and experimental results are in a good agreement.