Patrick Research Group - Organic Electronics

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Home Research Liquid crystals Nanomaterials Thin Films Organic electronics Theory & simulation Instrumentation People Current members Hall of fame Awards Photo Album Environs Lab tour City of Bellingham Directions & map Other stuff Publications News stories Getting involved liquid crystal nanomaterial STM scanning tunneling microscopy AFM atomic force microscopy nanoparticle organize order disorder ordered nematic smectic magnetic field electric field organic semiconductor carbon nanotube optical microscopy surface science materials science university research chemistry physics physical chemistry mesogen phase transition publication simulation molecular nano nanometer nanoscience nanomaterial nanotechnology technology patent scanning probe microscopy rhk multimode spm atomic resolution nanometer scale oriented film monolayer David L Patrick David Patrick Dr. Patrick WWU Washington		Organic electronics. Crystalline films of organic semiconductors are receiving considerable attention lately due to their interesting and potentially useful electronic, optical, magnetic, and chemical properties. The scope of application for these materials is remarkably broad: they have been used in thin film transistors, light emitting diodes, and photovoltaics; as chemical sensors; and as conductors, semiconductors, superconductors, and magnetic materials. Consequently, there has been a worldwide research effort directed at understanding the properties of organic molecular crystals, synthesizing compounds with improved performance, and incorporating them into functional devices. This effort has produced many important insights into the properties of organic solids and has established that, among other factors, careful control over molecular order at nanometer to micron length scales is critically important. Our research centers on a new method for growing organic crystalline films we call organic vapor liquid solid deposition (OVLS), illustrated in the picture below. OVLS involves atmospheric-pressure, vapor-phase deposition of organic crystalline building blocks onto a substrate coated with a thin layer of a liquid or liquid crystal solvent, where crystals nucleate and grow. The technique offers several advantages over conventional vacuum deposition methods, including mild processing conditions and compatibility with a range of substrates, including polymers; as well as larger crystals, better control over morphology, and - when a liquid crystal solvent is used - control over in-plane crystallographic orientation. The figure below shows a polarized optical micrograph of a film of tetracene grown using OVLS with a thermotropic liquid crystal solvent. The scale bar is 100 mm. References "Engineered Growth of Organic Crystalline Films Using Liquid Crystal Solvents", F. Scott Wilkinson, R. F. Norwood, Joseph M. McLellan, L. Rhys Lawson, David L. Patrick, J. Am. Chem. Soc., 2006 128, 16468. pdf supporting information (pdf)	A tetracene crystal grown using OVLS. Scale bar is 20 mm. Orientational order in a tetracene film grown using OVLS with a LC solvent. An X-ray diffractogram of a tetracene film grown using OVLS. A view of the Chemistry building.