Material would allow users to ‘tune’ windows to block targeted wavelengths of light

Phys.org   September 26, 2023 Dual-band electrochromism, the independent modulation of visible and near-infrared light by a single material, is highly desirable for smart windows to enhance the energy efficiency of buildings. Tungsten oxides are commercially important electrochromic materials, exhibiting reversible visible and near-infrared absorption when electrochemically reduced in an electrolyte containing small cations or protons. The presence of structural water in tungsten oxides has been associated with faster electrochromic switching speeds. A team of researchers in the US (North Carolina State University, UT Austin, Vanderbilt University) found that WO3·H2O, a crystalline hydrate, exhibited dual-band electrochromism unlike the anhydrous WO3. Making […]

Controlling the optical properties of solids with acoustic waves

Science Daily  December 2, 2019 So far moderately large changes in the exitons control parameters — temperature, pressure, electric and magnetic fields that can tune excitonic properties have only been achieved under equilibrium conditions and at low temperatures. An international team of researchers (Switzerland, Spain, Germany, USA- Simons Foundation Flatiron Institute, France) has demonstrated the control of excitonic properties using acoustic waves in titanium dioxide at room temperature. To do this, the researchers launched a high-frequency (hundreds of gigahertz), large-amplitude acoustic wave in the material using ultrashort laser pulses. This strategy allows for the dynamical manipulation of the exciton properties […]