Retrieval of Optical and Dielectric Constants of PBDTTTPD Polymer Film by Unconstrained Optimization Method

Abstract

Till now, optical and dielectric constants of polymer based on poly(benzo[1,2-b:4,5-b’]- dithiophene–thieno [3,4-c]pyrrole-4,6-dione) (PBDTTPD) incorporated into thiophene (PBDTTTPD) have not been systematically investigated. In this work, PBDTTTPD thin film was prepared on ITO glass substrate. Transmittance spectra of ITO and PBDTTTPD films were measured. Based on unconstrained optimization method, the glass was firstly as the substrate, the thickness and the refractive index of the ITO were retrieved. Then the refractive index data of the ITO thin film were added to the PUMA program and the ITO was taken as the new substrate, the thickness, optical and dielectric constants of the PBDTTTPD film were further simulated only via the transmittance spectra. These optical and dielectric parameters are promising useful in design optical devices related to PBDTTTPD polymer.