Research

Our current research topics include:


  • Radical Polymers for Memory Devices
    The 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.
    SEE THE ARTICLE HERE

    Supported by an NSERC Strategic Partnership Grant with an industry partner.


  • Graphene Thin Films for Applications requiring High Thermal Conductivity
    Graphene–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.
    SEE THE REVIEW ARTICLE HERE

    Supported by an NSERC Engage Grant with an industry partner.


  • Thermal Conductivity Imaging at the Nanoscale
    Thermoreflectance, 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.
    SEE THE ARTICLE HERE

    Supported by NSERC.


  • Two-dimensional Materials for Water Filtration Applications
    A 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.
    SEE THE ARTICLE HERE

    Supported by Western University and Ontario Centres of Excellence Inc. in collaboration with an industry partner.


  • Advanced Scanning Near-field Optical Microscopy (SNOM) Techniques for Solar Cell and other Optoelectronic Applications
    Using 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.
    SEE THE ARTICLE HERE

    We report a facile fabrication method for copper nanoparticle superlattices, based on thermal evaporation of ultrathin layers of copper on solution-processed thin films formed by few-layer graphene platelets. The possibility of using these superlattices in evanescent waveguiding devices is explored by three-dimensional scanning near-field optical microscopy. The light-confining properties of our systems in the near-field indicate that our nanoparticle superlattices are poised to satisfy the technological demands required by nanophotonics devices.
    SEE THE ARTICLE HERE

    SEE OUR REVIEW ARTICLE HERE

    Supported by the Canada Research Chair (CRC) Secretariat.


  • Plasmonic Organic Solar Cells
    The 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.
    SEE THE ARTICLE HERE

    Supported by MITACS, an NSERC Discovery Grant and an NSERC Engage Grant in collaboration with an industry partner.

Research Funding

Research Funding