4883 results about "Nanocrystal" patented technology

A coated nanocrystal capable of light emission includes a substantially monodisperse nanoparticle selected from the group consisting of CdX, where x=S, Se, Te and an overcoating of ZnY, where Y=S, Se, uniformly deposited thereon, said coated nanoparticle characterized in that when irradiated the particles exhibit photoluminescence in a narrow spectral range of no greater than about 60 nm, and most preferably 40 nm, at full width half max (FWHM). The particle size of the nanocrystallite core is in the range of about 20 Å to about 125 Å, with a deviation of less than 10% in the core. The coated nanocrystal exhibits photoluminescence having quantum yields of greater than 30%.

Capsules and similar objects are made from materials having diamond (sp³) lattice structures, including diamond materials in synthetic crystalline, polycrystalline (ordered or disordered), nanocrystalline and amorphous forms. The capsules generally include a hollow shell made of a diamond material that defines an interior region that may be empty or that may contain a fluid or solid material. Some of the capsules include access ports that can be used to fill the capsule with a fluid. Capsules and similar structures can be manufactured by growing diamond on suitably shaped substrates. In some of these methods, diamond shell sections are grown on substrates, then joined together. In other methods, a nearly complete diamond shell is grown around a form substrate, and the substrate can be removed through a relatively small opening in the shell.

This invention provides composite materials comprising nanostructures (e.g., nanowires, branched nanowires, nanotetrapods, nanocrystals, and nanoparticles). Methods and compositions for making such nanocomposites are also provided, as are articles comprising such composites. Waveguides and light concentrators comprising nanostructures (not necessarily as part of a nanocomposite) are additional features of the invention.

Non-volatile memory devices and arrays are described that utilize reverse mode non-volatile memory cells that have band engineered gate-stacks and nano-crystal charge trapping in EEPROM and block erasable memory devices, such as Flash memory devices. Embodiments of the present invention allow a reverse mode gate-insulator stack memory cell that utilizes the control gate for programming and erasure through a band engineered crested tunnel barrier. Charge retention is enhanced by utilization of high work function nano-crystals in a non-conductive trapping layer and a high K dielectric charge blocking layer. The band-gap engineered gate-stack with symmetric or asymmetric crested barrier tunnel layers of the non-volatile memory cells of embodiments of the present invention allow for low voltage tunneling programming and erase with electrons and holes, while maintaining high charge blocking barriers and deep carrier trapping sites for good charge retention.

A film-forming composition contains surface-treated nanocrystalline particles dispersed in a cross-linkable resin. A substantially transparent, abrasion-resistant film is formed from the film-forming composition. Processes for preparing the film-forming composition and for preparing a substantially transparent, abrasion-resistant film are also included. The surface-treated nanocrystalline particles may be obtained by treating nanocrystalline particles with one or more siloxane species, such as a siloxane star-graft polymer coating.

Nanoparticle compositions of noble metals, and methods of making them, are described. The nanoparticle compositions are made by reacting a salt or complex of a noble metal, such as Au, Ag, Cu or Pt, with a weak ligand, and a reducing agent, in a single liquid phase. The noble metal is typically provided as a halide or carboxylate. The ligand is preferably a fatty acid or aliphatic amine. The reducing agent is preferably a borohydride reagent, hydrazine, or a mixture thereof. Nanocrystals in the size range of 1 nm to 20 nm are produced, and can be made in substantially monodisperse form.

The present invention provides methods for hermetically sealing luminescent nanocrystals, as well as compositions and containers comprising hermetically sealed luminescent nanocrystals. By hermetically sealing the luminescent nanocrystals, enhanced lifetime and luminescence can be achieved.

The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.

Embodiments of the present invention involve photovoltaic (PV) cells comprising a semiconducting nanorod-nanocrystal-polymer hybrid layer, as well as methods for fabricating the same. In PV cells according to this invention, the nanocrystals may serve both as the light-absorbing material and as the heterojunctions at which excited electron-hole pairs split.

A photonic structure for “white” light generation by phosphors under the excitation of a LED. The photonic structure mounts the LED and an optically transparent nanocomposite matrix having dispersed therein phosphors which will emit light under the excitation of the radiation of the LED. The phosphors dispersed in the matrix may be nanocrystalline, or larger sized with the addition of non light emitting, non light scattering nanoparticles dispersed within the matrix material so as to match the index of refraction of the matrix material to that of the phosphors. The nanocomposite matrix material may be readily formed by molding and formed into a variety of shapes including lenses for focusing the emitted light. A large number of the photonic structures may be arranged on a substrate to provide even illumination or other purposes.

Functionalized fluorescent nanocrystal compositions and methods for making and using these compositions are disclosed. The compositions are fluorescent nanocrystals coated with at least one material. The coating material has chemical compounds or ligands with functional groups or moieties with conjugated electrons and moieties for imparting solubility to coated fluorescent nanocrystals in aqueous solutions. The coating material provides for functionalized fluorescent nanocrystal compositions which are water soluble, chemically stable, and emit light with a high quantum yield and/or luminescence efficiency when excited with light. The coating material may also have chemical compounds or ligands with moieties for bonding to target molecules and cells as well as moieties for cross-linking the coating. In the presence of reagents suitable for reacting to form capping layers, the compounds in the coating may form a capping layer on the fluorescent nanocrystal with the coating compounds operably bonded to the capping layer.

The present invention provides polymeric compositions that can be used to modify charge transport across a nanocrystal surface or within a nanocrystal-containing matrix, as well as methods for making and using the novel compositions.

Nanocrystals, compositions, and methods that aid particle transport in mucus are provided. In some embodiments, the compositions and methods involve making mucus-penetrating particles (MPP) without any polymeric carriers, or with minimal use of polymeric carriers. The compositions and methods may include, in some embodiments, modifying the surface coatings of particles formed of pharmaceutical agents that have a low water solubility. Such methods and compositions can be used to achieve efficient transport of particles of pharmaceutical agents though mucus barriers in the body for a wide spectrum of applications, including drug delivery, imaging, and diagnostic applications. In certain embodiments, a pharmaceutical composition including such particles is well-suited for administration routes involving the particles passing through a mucosal barrier.

A light emitting assembly comprising a solid state device coupleable with a power supply constructed and arranged to power the solid state device to emit from the solid state device. A series of rare-earth doped silicon and/or silicon carbide nanocrystals that are either combined in a single layer or in individual layers that produce the required Red, Green, and Blue (RGB) emission to form a white light.

A method for preparing a multilayer of nanocrystals. The method includes the steps of (i) coating nanocrystals surface-coordinated by a photosensitive compound, or a mixed solution of a photosensitive compound and nanocrystals surface-coordinated by a material miscible with the photosensitive compound, on a substrate, drying the coated substrate, and exposing the dried substrate to UV light to form a first monolayer of nanocrystals, and (ii) repeating the procedure of step (i) to form one or more monolayers of nanocrystals on the first monolayer of nanocrystals. Further, an organic-inorganic hybrid electroluminescence device using a multilayer of nanocrystals prepared by the method as a luminescent layer. The luminescent efficiency and luminescence intensity of the electroluminescence device can be enhanced, and the electrical properties of the electroluminescence device can be controlled by the use of the multilayer of nanocrystals as a luminescent layer.

A nanoparticle including an inorganic core comprising at least one metal and/or at least one semi-conductor compound comprising at least one metal includes a coating or shell disposed over at least a portion of a surface of the core. The coating can include one or more layers. Each layer of the coating can comprise a metal and/or at least one semiconductor compound. The nanoparticle further includes a ligand attached to a surface of the coating. The ligand is represented by the formula: X-Sp-Z, wherein X represents, e.g., a primary amine group, a secondary amine group, a urea, a thiourea, an imidizole group, an amide group, a phosphonic or arsonic acid group, a phosphinic or arsinic acid group, a phosphate or arsenate group, a phosphine or arsine oxide group; Sp represents a spacer group, such as a group capable of allowing a transfer of charge or an insulating group; and Z represents: (i) reactive group capable of communicating specific chemical properties to the nanocrystal as well as provide specific chemical reactivity to the surface of the nanocrystal, and/or (ii) a group that is cyclic, halogenated, or polar a-protic. In certain embodiments, at least two chemically distinct ligands are attached to an surface of the coating, wherein the at least two ligands (I and II) are represented by the formula: X-Sp-Z. In ligand (I) X represents a phosphonic, phosphinic, or phosphategroup and in ligand (II) X represents a primary or secondary amine, or an imidizole, or an amide; In both ligands (I) and (II) Sp, which can be the same or different in the two compounds, represents a spacer group, such as a group capable of allowing a transfer of charge or an insulating group; Z, which can be the same or different in the two compounds, is a group chosen from among groups capable of communicating specific chemical properties to the nanoparticle as well as provide specific chemical reactivity to the surface of the nanoparticle. In preferred embodiments, the nanoparticle includes a core comprising a semiconductor material.

Optical and optoelectronic devices and methods of making same. Under one aspect, an optical device includes an integrated circuit an array of conductive regions; and an optically sensitive material over at least a portion of the integrated circuit and in electrical communication with at least one conductive region of the array of conductive regions. Under another aspect, a method of forming a nanocrystalline film includes fabricating a plurality of nanocrystals having a plurality of first ligands attached to their outer surfaces; exchanging the first ligands for second ligands of different chemical composition than the first ligands; forming a film of the ligand-exchanged nanocrystals; removing the second ligands; and fusing the cores of adjacent nanocrystals in the film to form an electrical network of fused nanocrystals. Under another aspect, a film includes a network of fused nanocrystals, the nanocrystals having a core and an outer surface, wherein the core of at least a portion of the fused nanocrystals is in direct physical contact and electrical communication with the core of at least one adjacent fused nanocrystal, and wherein the film has substantially no defect states in the regions where the cores of the nanocrystals are fused.