Researchers demonstrate a novel mechansim for the realization of an optical waveguide. This opens the possibility to realize a waveguide without any modulation of the refractive index. The optical delay necessary for the beam confinement is not achieved by a local modulation of the speed of light, but through an exotic effect called 'geometric phase'. Geometric phase is a temporal delay associated with changes in the propagation of light polarization, the latter corresponding roughly to the oscillation direction of the electromagnetic field.
Photodetectors with a spectral response from the ultraviolet (UV) to visible light have significant importance in modern industrial and scientific applications such as imaging, communication, environmental monitoring and day and nighttime surveillance. Compared to other materials, the photo-current conversions of two-dimensional transition metal dichalcogenides such as MoS2 nanosheets are impressive, making them great candidates for next-generation visible light photodetectors. Researchers have now developed a facile and low-cost solution processing strategy to fabricate mechanically flexible 2D organic-inorganic hybrid thin-film photodetectors on a conventional filter paper.
An recent analysis of the combined effect of nanoparticles and substrates on the concentration of mobile ions in liquid crystals considers both 100% pure and contaminated with ions substrates and nanoparticles. The results could be very useful for engineers trying to apply nanotechnology to liquid crystal devices. Specifically, the control of mobile ions in liquid crystals by means of nanoparticles and substrates of the cell tailored for specific applications - liquid crystal displays, light shutters, switches, modulators, etc.
Carbon nanotubes (CNTs), by possessing a uniquely large disparity among its intertube and intratube interaction strengths, have been established as ultralow friction nanostructures and are serving as testbeds for tuning frictional response. In new woirk, researchers now have revealed the phononic origins of friction in CNT oscillators. This work, for the first time, provides a precise connection between individual phonon mode scattering and friction force.
Complex oxide perovskite have been intensively researched for over half a century for their intriguing high temperature superconductivity, thermoelectric, ferroelectricity, colossal magnetoresistance. However, their large band gaps limit their interaction with visible photons. In new work, researchers propose transition metal perovskite chalcogenides (TMPCs) as a new class of versatile semiconductors for optoelectronic applications.
Flow batteries are regarded as one of the most promising energy storage technologies for stationary large-scale storage because the power capability and the energy storage capability of these storage systems can be sized independently, which benefits load balancing, peak shaving, power conversion and stand-alone power system. As an emerging rechargeable battery technology, lithium redox flow batteries (Li-RFB) represent an important advance which is distinct from conventional solid-state rechargeable batteries. Researchers have now demonstrated an all-metallocene-based non-aqueous redox flow battery with stable cycling performance and comparable energy density with current related energy storage technologies.
Next-generation electronics will be based on two-dimensional semiconductors, which have a significantly higher resistance than conventional silicon-based electronics. This development is significantly limited by the high contact resistance between the metal electrode and the 2D semiconductor. To minimize the energy dissipation and improve the device performance, it is critical to reduce the contact resistance. Researchers have now shown that MXenes, a class of 2D metal carbides or nitrides, can achieve low contact resistance with 2D semiconductors.
Researchers have shown that evaporation from the surface of a variety of nanostructured carbon materials can be used to generate electricity: the evaporation driven water flow in nanoporous carbon film converts ambient thermal energy into electricity via the water molecules' interaction with the carbon material. The team fabricated their device from a sheet of carbon black and two electrodes made from multi-walled carbon nanotubes. When inserted into deionized water, an open-circuit voltage between the two electrodes is generated.