A premixed photoluminescent composition and related hardened form and method of forming joints for pavers or stones. The premixed photoluminescent composition comprises solid aggregates; a photoluminescent particulate component adapted to emit light when photoexcited; and a binder. When in contact with an activator, oxygen or water, the binder is adapted to harden into a water-resistant binder matrix that bonds the solid aggregates and embeds the photoluminescent particulate component. In use, the water-resistant binder matrix has a transparency allowing transmission of at least a portion of the light emitted by the photoluminescent particulate component.

A process for synthesizing Cu.sub.2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu.sub.2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu.sub.2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu.sub.2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu.sub.2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu.sub.2-xS cores in the reaction, Cu.sub.2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.

A process for synthesizing Cu.sub.2-xS/PbS core/shell nanocrystals. Pb-oleate is mixed with 1-octadecene and heated to 60° C. Cu.sub.2-xS core solution and bis(trimethylsilyl)sulfide stock solution are added and the mixture is stirred at 60° C. for 6 minutes to form the PbS shell around the Cu.sub.2-xS nanocrystal cores. The flask is cooled and acetonitrile and toluene is added and the mixture is centrifuged to precipitate and remove the Cu.sub.2-xS/PbS core/shell nanocrystals from the reaction mixture. The reaction also produces homogeneously nucleated PbS nanocrystals, which are removed from the Cu.sub.2-xS/PbS core/shell reaction mixture via size-selective precipitation. By tailoring the amounts of Pb-oleate and bis(trimethylsilyl)sulfide stock solution in the reaction vessel, while maintaining their molar ratio of 1.5:1 and the number of Cu.sub.2-xS cores in the reaction, Cu.sub.2-xS/PbS core/shell nanocrystals having a predetermined shell thickness of PbS, and thus a predetermined level of chemical stability, can be obtained.

A premixed photoluminescent composition and related hardened form and method of forming joints for pavers or stones. The premixed photoluminescent composition comprises solid aggregates; a photoluminescent particulate component adapted to emit light when photoexcited; and a binder. When in contact with an activator, oxygen or water, the binder is adapted to harden into a water-resistant binder matrix that bonds the solid aggregates and embeds the photoluminescent particulate component. In use, the water-resistant binder matrix has a transparency allowing transmission of at least a portion of the light emitted by the photoluminescent particulate component.

Ligand-capped inorganic particles, films composed of the ligand-capped inorganic particles, and methods of patterning the films are provided. Also provided are electronic, photonic, and optoelectronic devices that incorporate the films. The ligands that are bound to the inorganic particles are composed of a cation/anion pair. The anion of the pair is bound to the surface of the particle and at least one of the anion and the cation is photosensitive.

Ligand-capped inorganic particles, films composed of the ligand-capped inorganic particles, and methods of patterning the films are provided. Also provided are electronic, photonic, and optoelectronic devices that incorporate the films. The ligands that are bound to the inorganic particles are composed of a cation/anion pair. The anion of the pair is bound to the surface of the particle and at least one of the anion and the cation is photosensitive.

The preparation method for fluorescent quantum dots includes: carrying out solvothermal reaction on a first evenly mixed reaction system containing a silver source, a negative ion source and a weakly polar solvent to prepare a silver-based quantum dots precursor; and carrying out ion exchange reaction on a second evenly mixed reaction system containing the silver-based quantum dots precursor, a negative ion source and/or a metal positive ion source to obtain alloyed fluorescent quantum dots with a fluorescence emission peak wavelength of 500-1700 nm and an absolute quantum efficiency of more than 85%. The silver-based quantum dots are prepared through a simple high-temperature solvothermal method and then the alloyed quantum dots are obtained by the ion exchange method, and therefore the synthesis process is simple and controllable. The obtained fluorescent quantum dots can be prepared on large scale, and have adjustable fluorescence emission from visible to near-infrared region and excellent photostability.

The preparation method for fluorescent quantum dots includes: carrying out solvothermal reaction on a first evenly mixed reaction system containing a silver source, a negative ion source and a weakly polar solvent to prepare a silver-based quantum dots precursor; and carrying out ion exchange reaction on a second evenly mixed reaction system containing the silver-based quantum dots precursor, a negative ion source and/or a metal positive ion source to obtain alloyed fluorescent quantum dots with a fluorescence emission peak wavelength of 500-1700 nm and an absolute quantum efficiency of more than 85%. The silver-based quantum dots are prepared through a simple high-temperature solvothermal method and then the alloyed quantum dots are obtained by the ion exchange method, and therefore the synthesis process is simple and controllable. The obtained fluorescent quantum dots can be prepared on large scale, and have adjustable fluorescence emission from visible to near-infrared region and excellent photostability.

A copper-doped glass formed by placing a target glass in a container, surrounding the target glass with a powder mixture comprised of SiO.sub.2 powder and Cu.sub.2S powder, wherein the SiO.sub.2 powder and the Cu.sub.2S powder are mixed according to the formula (SiO.sub.2).sub.(1-x)(Cu.sub.2S).sub.x, where 0.01<x<0.1, and heated to a temperature of between 800° C. and 1150° C. for a duration of between 1 and 10 hours.

Disclosed herein are composite materials that comprise one or more nanophosphors capable of converting higher frequency, lower wavelength radiation into visible light. As used, the produced visible light enhances the amount of visible light already present from natural or artificial sources.