Annealing effects on electrical, optical and structural properties of semiconducting transparent tetra-tert-butyl 2,3 naphthalocyanine thinfilms

Although there are lot of early reports on inorganic semiconducting transparent thinfilms, very few experimental results have been reported regarding the organic semiconducting transparent thinfilms especially in the area of Naphthalocyanines. Here we report on the preparation and characterization of transparent and semiconducting 2,11,20,29 Tetra Tert-Butyl 2,3 Naphthalocyanine (TTBNc) thinfilms using Physical Vapor Deposition Technique. Post deposition air and vacuum annealing is done on thinfilms. From the DC electrical conductivity studies, the activation energy has been calculated using the Arrhenius plot and the bandgap energy has been obtained from the optical transmission spectra. The different structural parameters like crystal structure; grain size and surface morphology are measured from the x-ray diffraction (XRD) and scanning electron microscopic analysis (SEM) respectively. Atomic force microscopic (AFM) images of different TTBNc thinfilms account for significant changes on surface level patterns and a clear evidence of agglomeration of nano crystalline materials. Further the average grain size is calculated and confirmed in the nano level at which it forms clusters to get the particular surface topology. (C) 2011 Elsevier B.V. All rights reserved.