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The dynamic photoluminescence properties, and potential quenching mechanisms, of anti-B18H22, 4,4′-Br2-anti-B18H20, and 4,4′-I2-anti-B18H20 are investigated in solution and polymer films.

The dynamic photoluminescence properties, and potential quenching mechanisms, of

Transparent electric conductors made of indium tin oxide (ITO)-doped glass prepared by a flash lamp annealing (FLA) process were compared with ITO-doped glass prepared via a conventional rapid thermal annealing (RTA) process. Stylus surface profilometry was used to determine thicknesses, scanning electron microscopy was used to image surfaces, X-ray diffraction was used to determine film structures, X-ray photoelectron spectroscopy was used to determine oxidation states and film compositions, 4-point probe measurements were used to determine electrical conductivities, UV–Vis spectroscopy was used to determine film transparencies, and selective light filtering was used to determine which wavelengths of light are needed to anneal ITO into a visibly transparent electrically conductive thin film via an FLA process. The results showed that FLA with visible light can be used to nearly instantaneously anneal ITO to create visibly transparent and electrically conductive ITO thin films on glass. The FLA process achieved this by predominately exciting unoxidized indium, unoxidized tin, tin monoxide (SnO), and non-stoichiometric indium oxide (InO x ), appropriately distributed in an electron beam physical vapor-deposited amorphous ITO thin film, to allow their oxidation and crystallization into an electrically conductive visibly transparent ITO. Though it is possible to prepare ITO-doped glass that is more transparent with an RTA process, the FLA process is significantly faster, has comparable electrical conductivity, and can strongly localize heating to areas of the as-deposited ITO thin film that are not electrically conductive and visibly transparent.

We demonstrate that photonic media, when properly randomized to minimize the photon transport mean free path, can be used to coat a black substrate and reduce its temperature by radiative cooling. Even under strong solar radiation, the substrate temperature could reach substantially below that of the ambient air. Our random media that consist of silica microspheres considerably outperform commercially available solar-reflective white paint for daytime cooling. We have achieved the outstanding cooling performance through a systematic study on light scattering, which reveals that the structural parameters of the random media for maximum scattering are significantly different from those of the commercial paint. We have created the random media to maximize optical scattering in the solar spectrum and to enhance thermal emission in the atmospheric transparency window. In contrast to previous studies, our random media do not require expensive processing steps or materials, such as silver, and can be applied to ...

This work investigates the electrochemical dynamics and performance of additively manufactured composite electrolytes for resistive switching. Devices are comprised of a Ag/AgI–Al2O3/Pt stack, where the solid state electrolyte is additively manufactured using extrusion techniques. AgI–Al2O3 composite electrolytes are characterized by x-ray diffraction and electrochemical impedance spectroscopy. The ionic conductivities of the electrolytes were measured for different concentrations of Al2O3, observing a maximum conductivity of 4.5 times the conductivity of pure AgI for composites with 20 mol. % Al2O3. There was little change in activation energy with the addition of Al2O3. Setting the Ag layer as the positive electrode and the Pt layer as the negative electrode, a high conductivity state was achieved by applying a voltage to electrochemically establish an electrically conducting Ag filament within the solid state AgI–Al2O3 electrolyte. The low conductivity state was restored by reversing this applied voltage to electrochemically etch the newly grown Ag filament. Pure AgI devices switch between specific electrical resistivity states that are separated by five orders of magnitude in electrical conductivity. Endurance tests find that the AgI resistive switches can transition between a low and high electrical conductivity state over 8500 times. Composite AgI–Al2O3 resistive switches formed initial Ag filaments significantly faster and also demonstrated two orders of magnitude separation in resistivity when cycling for 1600 cycles.

Electrochemical systems offer a versatile means for creating adaptive devices. However, the utility of electrochemical deposition is inherently limited by the properties of the electrolyte. The development of ionic liquids enables electrodeposition in high-vacuum environments and presents opportunities for creating electrochemically adaptive and regenerative spacecraft components. In this work, we developed a silver-rich, boron cluster ionic liquid (BCIL) for reversible electrodeposition of silver films. This air and moisture stable electrolyte was used to deposit metallic films in an electrochemical cell to tune the emissivity of the cell in situ, demonstrating a proof-of-concept design for spacecraft thermal control.

Electrochemical systems offer a versatile means for creating adaptive devices. However, the utility of electrochemical deposition is inherently limited by the properties of the electrolyte. The development of ionic liquids enables electrodeposition in high-vacuum environments and presents opportunities for creating electrochemically adaptive and regenerative spacecraft components. In this work we developed a silver-rich, boron cluster ionic liquid (BCIL) for reversible electrodeposition of silver films. This air and moisture stable electrolyte was used to deposit metallic films in an electrochemical cell to tune the emissivity of the cell in situ, demonstrating a proof-of-concept design for spacecraft thermal control.