Description and test of a new multilayer thin film vapor deposition apparatus for organic semiconductor materials

Abstract

In this work the description, test, and performance of a new vacuum apparatus for thin film vapor deposition (ThinFilmVD) of organic semiconductor materials are presented. The apparatus is able to fabricate single, multilayer/ composites, or hybrid thin films using four independent, organic or inorganic, vapor deposition sources (Knudsen cells type), and the vapor mass flow is condensed onto a substrate surface (temperature regulated). The same apparatus could be also used to measure vapor pressures according to the Knudsen effusion methodology. Vapor pressures and thermodynamic properties of sublimation measured by Knudsen effusion of some reference organic materials (benzoic acid, anthracene, triphenylene, benzanthrone, 1,3,5-triphenylbenzene, perylene) were used to evaluate and test the performance of the apparatus. Moreover, nanostructures of thin films and composite materials of relevant charge transport and electroluminescent materials were deposited onto an indium−tin oxide (ITO) surface, and the morphology and thin film thickness were evaluated by scanning electron microscopy (SEM), exploring the effect of different mass flow rates and deposition time. The new physical vapor deposition apparatus based in four Knudsen effusion cells with an accurate mass flow control was designed to assemble well-defined (composition, morphology, thickness) thin films of organic semiconductors based on their volatility. The described apparatus presents a high versatility to the fabrication of single/multilayer thin films, asgrown crystals, and hybrid micro- and nanostructured materials