Determination of the optical constants of thin films of regioregular poly(3-alkylthiophene) on transparent substrates

The methods of reflection and transmission are used to determine the optical constants n and k of thin films of regioregular poly (3-octylthiophene). The technique is based on the simultaneous use of Fresnel laws and the dispersion relations between n and k of the film using an iterative process. The optical and Tauc gaps are also derived.