Lead-free, silicon compatible materials showing large electromechanical responses comparable to, or better than conventional relaxor ferroelectrics, are desirable for various nanoelectromechanical devices and applications. Defect-engineered electrostriction has recently been gaining popularity to obtain enhanced electromechanical responses at sub 100 Hz frequencies. Here, we report record values of electrostrictive strain coefficients (M) at frequencies as large as 5 kHz (1.
View Article and Find Full Text PDFWith the increase of drug resistance, there is a need for surface coatings that inhibit microbes without antibiotics. Nanostructured photocatalysts, like TiO-coated nanotubes, are promising alternatives to antibiotics. Nanostructures rupture the cell wall by impaling the bacteria.
View Article and Find Full Text PDFAntimicrobial surfaces can reduce the spread of bacteria from high-touch surfaces, saving millions of lives worldwide. Antibacterial photocatalytic films, like TiO, are widely reported but limited in practice because they need high-intensity UV light. More practical but less reported are photocatalysts that work under low-intensity visible light from an indoor lamp.
View Article and Find Full Text PDFThere are very few p-type semiconductors available compared to n-type semiconductors for positive sensing response for oxidizing gases and other important electronic applications. Cupric oxide (CuO) is one of the few oxides that show p-type conductivity, useful for sensing oxidizing gases. Many researchers obtained CuO using the chemical and solid-state routes, but uniformity and large-area deposition have been the main issues.
View Article and Find Full Text PDFCuO is a multifunctional metal oxide excellent for chemiresistive gas sensors. In this work, we report CuO-based NO sensors fabricated chemical vapor deposition (CVD). CVD allows great control on composition, stoichiometry, impurity, roughness, and grain size of films.
View Article and Find Full Text PDFLight-matter interaction in graphene can be engineered and substantially enhanced through plasmonic sensitization, which has led to numerous applications in photodetection, sensing, photocatalysis and spectroscopy. The majority of these designs have relied on conventional plasmonic materials such as gold, silver and aluminum. This limits the implementation of such devices to the ultraviolet and visible regimes of the electromagnetic spectrum.
View Article and Find Full Text PDFThe efficiency of photocatalytic antibacterial surfaces is limited by the absorption of light in it. Light absorption in photocatalytic surfaces can be enhanced by structuring it, leading to increased generation of reactive oxygen species (ROS) and hence improved bactericidal efficacy. A second, more passive methodology to kill bacteria involves the use of sharp nanostructures that mechanically disrupt the bacterial membrane.
View Article and Find Full Text PDFWe report acetamidinium (AA)-substituted methylammonium (MA) lead iodide perovskite solar cells. AA has a restricted C-N bond rotation because of delocalized π-electron cloud over the N-C-N bond and the presence of an additional N-H···I bond (4H-bond in AA as compared to 3H-bond in MA). These bonding structures strengthen the electrostatic interaction and stabilize the AA cation inside the perovskite matrix.
View Article and Find Full Text PDFA hybrid approach to solar cells is demonstrated in which a silicon p-n junction, used in conventional silicon-based photovoltaics, is replaced by a room-temperature fabricated silicon/organic heterojunction. The unique advantage of silicon/organic heterojunction is that it exploits the cost advantage of organic semiconductors and the performance advantages of silicon to enable potentially low-cost, efficient solar cells.
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