Abstract: The present invention provides a device or medical device comprising a graphene coating. Particularly, the graphene coating features substantially high transmittance, biointegrity and biocompatibility.

Abstract: A method for preparing a core-shell nanocrystal can include mixing an M-containing precursor solution, an X-containing precursor solution, and an acid or alcohol in an inert atmosphere at a first temperature to form a reaction mixture; maintaining the reaction mixture at the first temperature to grow the MX core of the nanocrystal; raising the temperature of the reaction mixture to a second temperature; and maintaining the reaction mixture at the second temperature to grow a shell of the nanocrystal.

Abstract: The present invention includes upconversion materials such as lanthanide-sensitized oxides that are useful for converting low-energy photons into high-energy photons. Because silicon-based solar cells have an intrinsic optical band-gap of 1.1 eV, low-energy photons having a wavelength longer than 1100 nm, e.g., infrared photons, cannot be absorbed by the solar cell and used for photovoltaic energy conversion. Only those photons that have an energy equal to or greater than the solar cell's band gap, e.g., visible photons, can be absorbed and used for photovoltaic energy conversion. The oxides described herein transform photons having an energy less than the energy of a solar cell's band gap into photons having an energy equal to or greater than the energy of the band gap. When these oxides are incorporated into a solar cell, they provide more photons for photovoltaic energy conversion than otherwise would be available in their absence.

Abstract: A re-dispersible, dry graphene powder can be formed by producing a solution of graphene sheets in solvent, adding surfactant to the solution, and then drying the solution to produce dry graphene sheets coated with surfactant.

Abstract: The present invention includes upconversion materials such as lanthanide-sensitized oxides that are useful for converting low-energy photons into high-energy photons. Because silicon-based solar cells have an intrinsic optical band-gap of 1.1 eV, low-energy photons having a wavelength longer than 1100 nm, e g., infrared photons, cannot be absorbed by the solar cell and used for photovoltaic energy conversion. Only those photons that have an energy equal to or greater than the solar cell's band gap, e.g., visible photons, can be absorbed and used for photovoltaic energy conversion. The oxides described herein transform photons having an energy less than the energy of a solar cell's band gap into photons having an energy equal to or greater than the energy of the band gap. When these oxides are incorporated into a solar cell, they provide more photons for photovoltaic energy conversion than otherwise would be available in their absence.