Annealing effect on the structural and Morphological properties of Organic Semiconductor Alq3:C60 blend Thin Films

Abstract

In this work, has been a studied the effect of thermal treatment using different annealing temperatures (373, 423 and 473) K in vacuum on structural and morphological properties of organic semiconductor Alq₃:C₆₀ thin films which are prepared by the spin coating on a glass, silicon and porous silicon.  These films have been coated on substrates with speed of 2000 rpm. The structure properties of Tris(8-hydroxyquinoline) aluminum (III) (Alq₃) and fullerene (C₆₀) (100:1) and (100:10) blend as-deposited and treated have been studied by X-ray diffraction (XRD) for glass only and morphological properties by Atomic Force Microscope (AFM) for silicon and porous silicon substrates. The results of XRD pattern shows that the structure of (Alq₃:C₆₀) as-deposited and annealed thin films are polycrystalline in nature for both mixed weight ratio. The result of AFM measurements show that grain size increase is due to the increases of surface energy at high temperature. Surface roughness increasing and decreased randomly with the temperature can be attributed to the random distributions of the grains and also due to the phase change.