Optical and structural properties of PVK/CA/PVK thin films fabricated by spin coating method

Polymeric thin films were fabricated by depositing three consecutive PVK/CA/PVK layers using spin coating method. Deposition parameters such as materials, rotation speed, rotation time and annealing conditions were determined and optimized to achieve homogenous and transparent layers. Fabricated thin films contain granular microstructures. X-Ray refraction pattern of PVK thin film showed that the annealed film was amorphous in 140 degrees C. Refractive index and extinction coefficient of PVK were determined by transmission spectrum. Transmission spectrum of samples showed that the layers absorb ultra-violet waves; and these layers are transparent against visible waves. Annealing the layers causes higher transparency. Optical band gap of layers wasineasured 3.5 eV which claims desirable consistency with recent data. (C) 2016 Elsevier GmbH. All rights reserved.