Abstract: A metal sulfide nanocrystal manufactured by a method of reacting a metal precursor and an alkyl thiol in a solvent, wherein the alkyl thiol reacts with the metal precursor to form the metal sulfide nanocrystals, wherein the alkyl thiol is present on the surface of the metal sulfide nanocrystal, wherein the alkyl thiol is bonded to the sulfur crystal lattice. A metal sulfide nanocrystal manufactured with a core-shell structure by a method of reacting a metal precursor and an alkyl thiol in a solvent to form a metal sulfide layer on the surface of a core, wherein the alkyl thiol is present on the surface of the metal sulfide nanocrystal, wherein the alkyl thiol is bonded to the sulfur crystal lattice. These metal sulfide nanocrystals can have a uniform particle size at the nanometer-scale level, selective and desired crystal structures, and various shapes.

Abstract: Disclosed herein are a dispersant for dispersing nanoparticles that are surface-bound with capping ligands in a polymer matrix having an epoxide group, a method for dispersing the nanoparticles using the dispersant, and a nanoparticle-containing thin film including the dispersant.

Abstract: The separation of carbon nanotubes into metallic carbon nanotubes and semiconducting carbon nanotubes is made to be possible simultaneously with the dispersion of the carbon nanotubes by using viologen.

Abstract: A nanocomposite material and a method of manufacturing the same are disclosed. The nanocomposite material includes a plurality of nanoparticles coated with a metal oxide, and a matrix of the metal oxide immobilizing the nanoparticles that are dispersed therein. The nanocomposite material is manufactured such that macro- or macro-scale cracks are prevented or effectively prevented, light stability is enhanced over a light-emitting period, and light brightness is improved.

Abstract: A cadmium sulfide nanocrystal, wherein the cadmium sulfide nanocrystal shows maximum luminescence peaks at two or more wavelengths and most of the atoms constituting the nanocrystal are present at the surface of the nanocrystal to form defects.

Abstract: A surface emitting device using a photonic crystal includes a two-dimensional slab type photonic crystal structure including a first dielectric layer and a second dielectric layer formed on top of the first dielectric layer wherein a plurality of air holes in a two-dimensional lattice pattern are formed on the surface of the second dielectric layer; a light-emitting material layer formed on the inner wall of the air holes; and optical pumping means for irradiating the lateral surface of the photonic crystal structure with light. The surface emitting device shows improved surface emission efficiency and can advantageously emit light close to monochromatic light. Therefore, the surface emitting device can be used to manufacture a surface emitting laser. A method for fabricating the surface emitting device is also disclosed.

Abstract: A nanowire composite and a method of preparing the nanowire composite comprise a template having a plurality of hollow channels, nanowires formed within the respective channels of the template, and a functional element formed by removing a portion of the template so that one or more of the nanowires formed within the portion of the template are exposed. Since the nanowire composite can be prepared in a simple manner at low costs and can be miniaturized, the nanowire composite finds application in resonators and a variety of sensors.

Abstract: Provided is a siloxane dispersant having a structure including a head part having an affinity for nanoparticles and a tail part having an affinity for a polydimethylsiloxane (PDMS) resin, and a nanoparticle paste composition comprising the same. The dispersant significantly improves dispersion efficiency of a polydimethylsiloxane resin system which is used in preparation of high-output light sources such as UV LEDs and the like.

Abstract: 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.

Abstract: A semiconductor nanocrystal, wherein the semiconductor nanocrystal shows maximum luminescence peaks at two or more wavelengths and most of the atoms constituting the nanocrystal are present at the surface of the nanocrystal to form defects

Abstract: 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.

Abstract: The memory device includes a source region and a drain region in a substrate and spaced apart from each other; a memory cell formed on a surface of the substrate, wherein the memory cell connects the source region and the drain region and includes a plurality of nanocrystals; a control gate formed on the memory cell. The memory cell includes a first tunneling oxide layer formed on the substrate; a second tunneling oxide layer formed on the first tunneling oxide layer; and a control oxide layer formed on the second tunneling oxide layer. The control oxide layer includes the nanocrystals. The second tunneling oxide layer, having an aminosilane group the increases electrostatic attraction, may be hydrophilic, enabling the formation of a monolayer of the nanocrystals.

Abstract: The separation of carbon nanotubes into metallic carbon nanotubes and semiconducting carbon nanotubes is made to be possible simultaneously with the dispersion of the carbon nanotubes by using viologen.

Abstract: Provided is method of selectively separating carbon nanotubes into metallic carbon nanotubes and semiconducting carbon nanotubes, the method including: preparing a mixture including a dispersant, carbon nanotubes, and a solvent; dispersing the carbon nanotubes in the mixture; and separating the semiconducting carbon nanotubes from the mixture in which the carbon nanotubes are dispersed, wherein the dispersant is an oligomer including about 2 to about 24 repeat units, each including a head moiety and a tail moiety, wherein the head moiety comprises 1 to about 5 aromatic hetero rings, and the tail moiety comprises a hydrocarbon chain or chains connected to the head moiety.

Abstract: Disclosed herein are methods for manufacturing a carbon nanotube (CNT) having electrons that are injected, with treatment with a reducing agent, a CNT manufactured according to the method, and an electric device comprising the CNT a CNT manufactured according to the method. The electronic characteristics such as the doped level and the band gap of the CNT having electrons injected therein can be widely and easily adjusted by changing the treatment conditions of the reducing agent.

Abstract: Disclosed is a carbon nanotube (CNT) thin film having metallic nanoparticles. The CNT thin film includes a plastic transparent substrate and a CNT composition coated on the substrate. The CNT composition includes a CNT and metallic nanoparticles distributed on the CNT surface. The plastic transparent substrate is flexible. The metallic nanoparticles are formed by heating a metallic precursor adsorbed in the CNT surface. A method of manufacturing the CNT thin film having metallic nanoparticles is also disclosed. A CNT-dispersed solution is prepared by mixing a CNT with a dispersant or a dispersion solvent. The CNT-dispersed solution is used to form a CNT thin film. Metallic precursors are implanted in the CNT thin film. Then, a heat-treatment is applied to transform the metallic precursors into metallic particles including metallic nanoparticles.

Abstract: A method for preparing cadmium sulfide nanocrystals emitting light at multiple wavelengths. The method comprises the steps of (a) mixing a cadmium precursor and a dispersant in a solvent that weakly coordinates to the cadmium precursor, and heating the mixture to obtain a cadmium precursor solution, (b) dissolving a sulfur precursor in a solvent that weakly coordinates to the sulfur precursor to obtain a sulfur precursor solution, and (c) feeding the sulfur precursor solution to the heated cadmium precursor solution maintained at a high temperature to prepare cadmium sulfide crystals, and growing the cadmium sulfide crystals. Further, cadmium sulfide nanocrystals prepared by the method. The cadmium sulfide nanocrystals have uniform size and shape and can emit light close to white light simultaneously at different wavelengths upon excitation. Due to these characteristics, the cadmium sulfide nanocrystals can be applied to white light-emitting diode devices.

Abstract: A carbon nano-tube CNT thin film and a manufacturing method thereof are provided. In detail, the CNT thin film comprises a plastic substrate; and a CNT composition being coated over the plastic substrate, in which the CNT composition includes a CNT; and an amine compound of boiling point lower than 150° C. used as a dispersion solvent. When the CNT composition is coated over the plastic substrate, an amine compound is contained in its dispersion liquid. This amine compound is then removed after the CNT composition is coated over the plastic substrate.

Abstract: A cadmium sulfide nanocrystal, wherein the cadmium sulfide nanocrystal shows maximum luminescence peaks at two or more wavelengths and most of the atoms constituting the nanocrystal are present at the surface of the nanocrystal to form defects.

Abstract: A metal sulfide nanocrystal manufactured by a method of reacting a metal precursor and an alkyl thiol in a solvent, wherein the alkyl thiol reacts with the metal precursor to form the metal sulfide nanocrystals, wherein the alkyl thiol is present on the surface of the metal sulfide nanocrystal, wherein the alkyl thiol is bonded to the sulfur crystal lattice. A metal sulfide nanocrystal manufactured with a core-shell structure by a method of reacting a metal precursor and an alkyl thiol in a solvent to form a metal sulfide layer on the surface of a core, wherein the alkyl thiol is present on the surface of the metal sulfide nanocrystal, wherein the alkyl thiol is bonded to the sulfur crystal lattice. These metal sulfide nanocrystals can have a uniform particle size at the nanometer-scale level, selective and desired crystal structures, and various shapes.