Two methods for the preparation of semiconductor doped sol-gel films, for applications in nonlinear optics, have been studied and compared. In the first, porous films are spun from sols containing the cation precursor, and then reacted with H$S gas, and in the second, the cation is adsorbed onto the pore surfaces of passive films from aqueous solution before the gas reaction. Extensive results ...

The ability to assemble nanoparticles into functional structures is an important challenge that needs to be addressed for the generation of nanoparticle-based devices. Sol-gel method represents a facile yet powerful strategy for the self-assembly of metal oxides, chalcogenides, and metal-semiconductor hybrid nanoparticle systems into three-dimensionally connected porous nanostructures. In contr...

UNLABELLED Mesoporous silicon and porous silicon/Ni nanocomposites have been investigated in this work employing light-dark surface photovoltage (SPV) transients to monitor the response of surface charge dynamics to illumination changes. The samples were prepared by anodization of a highly n-doped silicon wafer and a subsequent electrodepositing of Ni into the pores. The resulting pores were or...

Photocathodes are critical to the design of electron sources in high-power free-electron lasers but must maintain operational readiness and reliability with a long lifetime despite requisite high current density (hence high quantum efficiency), possible drive laser heating, and vacuum contamination. We at the University of Maryland have already demonstrated extended lifetime of cesiated metal p...

Metal–organic frameworks (MOFs) offer unique possibilities for the rational engineering of tailored physical properties. Nevertheless, molecular and porous nature MOFs leaves field juxtapositioned between semiconductor physics homogeneous photocatalysis. This Review reflects on how can resemble conventional semiconductors they are more like infinite molecules in solution.

Si-based surface plasmon resonance (SPR) in the Kretschmann-Raether geometry is considered as a platform for the optical measurement of high refractive index films. The implementation of the SPR effect becomes possible due to the relatively high index of refraction of Si compared to most materials. As examples we study the SPR responses for some important semiconductor-based films, including la...

A new generation of optically encoded beads has been prepared by using mesoporous polystyrene beads and surfactant-coated semiconductor quantum dots. In comparison with nonporous beads of similar sizes and chemical compositions, the encoded porous beads are approximately 1000 times brighter and 5 times more uniform in fluorescence intensities. Using both absolute intensity and ratiometric fluor...

We applied an automated semiconductor synthesis and screen system to discover overcoating film materials and optimize coating conditions on the BiVO4/WO3 composite photoelectrode to enhance stability and photocurrent. Thirteen metallic elements for overcoating oxides were examined with various coating amounts. The stability of the BiVO4/WO3 photoelectrode in a highly concentrated carbonate elec...

A new type of fluorescence sensory material with high sensitivity, selectivity, and photostability has been developed for vapor probing of organic amines. The sensory material is primarily based on well-defined nanofibers fabricated from an n-type organic semiconductor molecule, N-(1-hexylheptyl)perylene-3,4,9,10-tetracarboxyl-3,4-anhydride-9,10-imide. Upon deposition onto a substrate, the enta...