This article reports the effect of post deposition heating on the optical and mechanical properties of polythiophene thin film prepared by vacuum evaporation technique. The post deposition heating strongly affects on the structural, surface morphological, optical and electrical properties. As deposited thin film showed uniform surface morphology with very small grain size, whereas the heat treated thin film was highly dense with larger grains. It was observed that, the absorbance of the polythiophene thin films increases due to post deposition heating, while the band gap found to be decrease and refractive index increases. However the activation energy of the polythiophene thin films was decreased due to post deposition heating.
