LAUSR

Abstract Poly (3-octylthiophene) (P3OT) was prepared by traditional oxidative polymerization method using FeCl3 as oxidant. The prepared polymer was dissolved in chloroform, drop-casted onto substrates and the films were annealed at 100 and 175 °C in argon atmosphere. Annealing temperatures-induced structural and optical properties variations of P3OT films have been studied. Fourier transform infrared is used to check the stability of the films against thermal treatment. The grazing incident in-plan X-ray diffraction and field emission scanning electron microscope are used for studying the crystalline and surface morphology natures of the films. The photoluminescence of the films and the optical functions of as-casted and annealed P3OT films are discussed. The optical functions were extracted from the measured transmittance and reflectance spectra at normal incidence of the light over the spectral range 200–2500 nm. The absorption curves are analyzed and the influence of heat treatment on the optical band gap of the films is investigated. The refractive index is also analyzed, in which the dispersion parameters are estimated.