Simulation of the refractive index of Ga doped ZnO nanoparticles embedded in PEDOT:PSS using effective medium approximations

We have theoretically investigated the change of refractive index of nanocomposites composed of Ga-doped ZnO nanoparticles (Ga-ZnO NPs) dispersed in conductive polymer Poly(3,4-ethylenedioxythiophene) and Poly(styrene sulfonic acid) (PEDOT:PSS) matrix by tuning the fraction of the Ga-ZnO NP inclusions and concentration of Ga dopant in Ga-ZnO, by using Maxwell-Garnett, Bruggeman and Lorentz-Lorenz effective medium theories. The dependence of the effective refractive index of Ga-ZnO NPs embedded in PEDOT:PSS composite on the Ga doping concentration and its volume fraction of the inclusions are presented. Ga-ZnO NPs can increase the effective refractive index. This can be used to engineer a desired effective index of refraction for the enhancement of light extraction and absorption efficiency in optical devices such as organic light emitting diodes (OLEDs) and organic solar cells (OSCs). It is crucial to match the refractive indices of conductive anode electrode and the emissive layer.