Radical Polymers for Memory DevicesThe quest for flash memory devices that can retain information without any external power source and satisfy the thinness requirements of next‐generation electronics demands the development of device architectures with a homogeneous layer of active material that can be made as thin as possible. Here, an ultrathin memory device is presented in which the active layer is formed by a 10‐nm homogeneous film of a polyradical with three tunable charge states per radical monomer: positive, neutral, and negative. To the best of our knowledge, these are the thinnest organic flash memristors obtained to date.
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Two-Dimensional Materials for Water Filtration ApplicationsA new generation of membranes for water purification based on weakly oxidized and nanoporous few-layer graphene is introduced. These membranes dramatically decrease the high energy requirements of water purification by reverse osmosis. They combine the advantages of porous and non-oxidized single-layer graphene, offering energy-efficient water filtration at relatively low differential pressures, and highly oxidized graphene oxide, exhibiting high performance in terms of impurity adsorption.
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Graphene Thin Films for Applications requiring High Thermal ConductivityGraphene–polymer composites have shown great promise as thermal interface materials to replace state-of-the-art silver-grease thermal pastes. A deeper understanding of their inherent thermal properties irrespective of their interfacial thermal resistivity with other systems is required to develop them with a sufficient degree of generality for a host of thermal applications. We discuss some of the methods used for aligning graphene platelets with each other, to improve their directional thermal conductivity, and to understand how thermo-optical pump–probe techniques can be used for characterizing such systems, with PEDOT:PSS–graphene composite systems as working examples.
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Plasmonic Organic Solar CellsThe use of our nanocomposite hole-blocking layers for enhancing the photoconversion efficiency of bulk heterojunction organic solar cells is demonstrated. Improvement in organic solar cell efficiencies up to 10% relative to a reference cell is demonstrated with Tess-AuNPs embedded in PEDOT:PSS.
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Advanced Scanning Near-field Optical Microscopy Techniques for Solar Cell and other Optoelectronic ApplicationsUsing a 200 nm transparent spacer between the system of Cu-NPs and the solar cell active layer, we demonstrate that forward-scattered light can be conveyed in 200 nm thin film solar cells. This architecture increases the solar cell photoconversion efficiency by a factor of 3. Our 3D-SNOM technique is general enough to be suitable for a large number of other applications in nanoplasmonics.
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Thermal Conductivity Imaging at the NanoscaleThermoreflectance, a contactless technique in which thermal conductivity is measured by optically probing the heat-induced changes in a sample, is extensively used for measuring the macroscopic and microscopic thermal properties of solids, but, so far, has been limited by diffraction in its applicability at the nanoscale. Here, we present near-field scanning thermoreflectance imaging (NeSTRI), a new scanning probe technique in which an aperture-type near-field optical microscope at sub-wavelength resolution is used to contactlessly determine the thermoreflectance of thin films.
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