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%0 Thesis
%A Niyamakom, Phenwisa
%T Influence of deposition parameters on morphology, growth and structure of crystalline and amorphous organic thin films : (the case of perylene and alpha-NPD)
%C Aachen
%I Publikationsserver der RWTH Aachen University
%M RWTH-CONV-113111
%P IV, 161 S. : Ill., graph. Darst.
%D 2008
%Z Zsfassung in dt. und engl. Sprache
%Z Aachen, Techn. Hochsch., Diss., 2008
%X A growing research effort in organic electronics has been developped rapidly to utilize the electronic and optical properties of organic materials (polymers and oligomers) and hybrids (organic-inorganic composites) through novel material synthesis, thin film deposition techniques and many mores. Several applications, e.g. organic thin film transistors (OTFTs) and organic light emitting devices (OLEDs), have been envisioned in both academic research and industry. An understanding of thin film growth is crucial to tailor surface morphologies and organic film properties suitable for specific applications. In OTFTs, the highest possible electron mobilities are desired. Typically, the conductivity in crystalline organic materials is anisotropic and strongly depends upon the electronic coupling between the neighboring molecules in the different crystallographic directions. Therefore, highly textured crystalline organic thin films are required for electronic applications. In OLEDs, the absence of long-range order in amorphous films can result in smooth surfaces and effcient radiative recombination, which allows for the realization of high performance organic optoelectronic devices. Amorphous organic thin film hence are preferable in this case. In this dissertation, the growth, morphology and structure of organic thin films both of crystalline and amorphous films has been investigated. For the crystalline organic thin film growth in the case of perylene, we focus on two different topics, i.e. temperature dependence of dislocation formation in perylene films and the temperature dependence of perylene thin film growth on gold substrate. The temperature dependence of dislocation formation in perylene films has been studied to obtain a better understanding of dislocation-assisted growth in perylene films upon changing substrate temperatures. The surface morphology and structural properties have been studied by atomic force microscopy (AFM) and X-ray diffractometry (XRD). Subsequently, for the study of the temperature dependence of perylene thin film growth on gold substrates, molecular vibrations in the perylene films are studied and related to structural properties, including surface morphology, as investigated by Fourier transform infrared spectroscopy (FT-IR), XRD and AFM, respectively. In a subsequent chapter for the amorphous organic thin film growth in the case of a-NPD, two different deposition techniques, Organic Vapor Phase Deposition (OVPD) and Vacuum Thermal Evaporation (VTE), were chosen. A study of the influence of deposition parameters, on film properties has been performed. Subsequently, AFM and X-ray reflectometry (XRR) have been employed to investigate film morphology and structural properties.
%K Organischer Kristall (SWD)
%K Amorpher Festkörper (SWD)
%K Perylen (SWD)
%K Organischer Halbleiter (SWD)
%F PUB:(DE-HGF)11
%9 Dissertation / PhD Thesis
%U https://publications.rwth-aachen.de/record/50571