377 results about "Semiconductor quantum dots" patented technology

Provided are quantum dots having a gradual composition gradient shell structure which have an improvedluminous efficiency and optical stability, and a method of manufacturing the quantum dots in a short amount of time at low cost. In the method, the quantum dots can be manufactured in a short amount of time at low cost using a reactivity difference between semiconductor precursors, unlike in uneconomical and inefficient conventional methods where shells areformed after forming cores and performing cleaning and redispersion processes. Also, formation of the cores is followed by formation of shells having a composition gradient. Thus, even if the shells are formed to a large thickness, the lattice mismatch between cores and shells is relieved. Furthermore, on the basis of the funneling concept, electrons and holes generated in the shells are transferred to the cores to emit light, thereby obtaining a high luminous efficiency of 80% or more. The quantum dot structure is not limited to Group II-IV semiconductor quantum dots but can be applied to other semiconductors quantum dots, such as Group III-V semiconductors quantum dots and Group IV-IV semiconductors quantum dots. Also, the manufacturing method can be utilized in the development of semiconductor quantum dots having different physical properties, and in various other fields.

An alloyed semiconductor quantum dot comprising an alloy of at least two semiconductors, wherein the quantum dot has a homogeneous composition and is characterized by a band gap energy that is non-linearly related to the molar ratio of the at least two semiconductors; a series of alloyed semiconductor quantum dots related thereto; a concentration-gradient quantum dot comprising an alloy of a first semiconductor and a second semiconductor, wherein the concentration of the first semiconductor gradually increases from the core of the quantum dot to the surface of the quantum dot and the concentration of the second semiconductor gradually decreases from the core of the quantum dot to the surface of the quantum dot; a series of concentration-gradient quantum dots related thereto; in vitro and in vivo methods of use; and methods of producing the alloyed semiconductor and concentration-gradient quantum dots and the series of quantum dots related thereto.

The invention discloses a magnetic composite nano microsphere capable of emitting fluorescent light and a preparation method thereof, which belong to the inorganic nanophase material field. The preparation method comprises the following steps: firstly, the sol-gel method or the reversed phase microemulsion method is adopted for performing base catalysis on alkyl silicate, and a layer of silicon dioxide is uniformly coated on the surface of inorganic magnetic nano particles; secondly, an amino silane coupling agent is adopted for performing surface finish on silicone dioxide; thirdly, semiconductor quantum dots are absorbed on the surface of the silicone dioxide through the electrostatic action between an amino group and a carboxyl group on the surface of the amino silane coupling agent; and fourthly, the magnetic composite nano microsphere with a core-shell structure capable of emitting the fluorescent light is obtained. The preparation method has easy obtained raw materials and low cost. The composite nano microsphere obtained has good stability, controllable grain size, narrow distribution, and has good magnetic responsivity and performance of being capable of emitting the fluorescent light, and the two performances are controllable. The magnetic composite nano microsphere and the preparation method can be applied in the fields of biomedicine, bioengineering, etc. including immunoassay, biological labeling and separation, cell imaging and so on.

An organic-inorganic hybrid nanocomposite thin film for a high-powered and/or broadband photonic device having an organic ligand-coordinated semiconductor quantum dot layer, a photonic device having the same, and a method of fabricating the same are provided. The organic-inorganic hybrid nanocomposite thin film is composed of a stack structure comprising a polymer layer and an organic ligand-coordinated semiconductor quantum dot layer self-assembled on the polymer layer, or composed of a first composite thin film comprising a first polymer layer pattern having a first hole, and an organic ligand-coordinated first semiconductor quantum dot layer pattern filling the first hole. The organic-inorganic hybrid nanocomposite thin film may be formed by spin-coating a semiconductor quantum dot solution and a polymer solution alternately to be stacked by one layer so as to form a multi-layered organic thin film composed of a plurality of layers. The hybrid nanocomposite thin film for a photonic device may be provided by physically coupling a high concentration and broadband semiconductor quantum dot layer and a polymer layer so as to realize a photonic device with high power, broadband, high brightness, and high sensibility, and a flexible photonic device may be also provided.

The invention discloses a preparation method and application in the luminescent element thereof of CuInS2-ZnS/ZnSe/ZnS semiconductor quantum dots with a core-shell structure, belonging to the technical field of the preparation method of the semiconductor quantum dot. The method comprises the following steps: dissolving the precursors of copper source, zinc source, indium source and sulfur source in nonpolar mixed solvent to perform nucleation and growth under a certain temperature and obtain a CuInS2-ZnS alloy core-ZCIS, then adding zinc source and selenium source alternately in the solution to perform epitaxial growth of ZnSe on the core, then perform epitaxial growth of ZnS to prepare the CuInS2-ZnS/ZnSe/ZnS quantum dots, finally adding polar solvent in the solution, settling, centrifuging, cleaning, and perform vacuum drying to obtain solid quantum dot powder. The prepared quantum dots are 2-8nm and have uniform particle size, controllable emission wavelength and high yield. The quantum dots are used as luminescent material to prepare red, yellow and green quantum dot luminescent elements and the luminescent elements have excellent luminescent property.

The present invention provides a semiconductor based photovoltaic device and a manufacturing method thereof. The semiconductor based photovoltaic device is able to absorb light with a wide band wavelength, and has high photoelectric conversion efficiency since it has high electron-hole pair separation efficiency. More specifically, the method for manufacturing the photovoltaic device comprises the steps of: a) forming a thin semiconductor quantum dot film on a p or n-type semiconductor substrate, wherein the thin semiconductor quantum dot film includes semiconductor quantum dots inside a medium at which the same type of impurities as the semiconductor substrate are doped; b) forming a pore array through partial etching, wherein the pore array penetrates the thin semiconductor quantum dot film; c) depositing a semiconductor in which complementary impurities to the semiconductor substrate are doped on the thin semiconductor quantum dot film at which the pore array is formed; and d) forming sequentially a transparent conductive film and an upper electrode on the semiconductor in which the complementary impurities are doped and forming a lower electrode at a lower portion of the semiconductor substrate.

The invention belongs to the technical field of biomolecular labeling, in particular to a method for preparing an amino functional magnetic fluorescent coding microsphere with double-nucleocapsid structure. Two semiconductor quantum dots with different fluorescence colors and superparamagnetic ferric oxide nano-particles are embedded in a same silicon dioxide nano-particle in inverse microemulsion to form an amino functional magnetic fluorescent coding microsphere which has the granularity between 40nm and 100nm, high fluorescence intensity and high stability. The invention adjusts the fluorescence position and the intensity of the microsphere by changing the sort and the proportion of the quantum dots of different fluorescence colors and realizes different fluorescent coding. The addition of superparamagnetic ferroferric oxide ensures that the microsphere can gather and move fast in a targeted way under the action of an externally-applied magnetic field. Through amido modification on the surface of the microsphere, the invention can be widely applied to the fields of immunological test, nucleic acid hybridization, gene analysis, cell classification and imaging, etc.

The invention discloses a method for preparing a graphene/semiconductor quantum dot composite material, which belongs to the technical field of inorganic nano materials and prepares the graphene/semiconductor quantum dot composite material by preparing solution of single-layer graphene and solution of quantum dots and uniformly mixing the solution of graphene and the solution of quantum dots. The surfaces of the quantum dots synthesized by using mercaptan acid as a stabilizer of the invention have carboxyls, while the surfaces of graphene slices prepared by a chemical oxidation reduction process have hydroxys; therefore, the carboxyls can be bonded with the hydroxys by covalent bonds to form the graphene/quantum dot composite material. As the graphene and the quantum dots mutual soluble in water, ligand disreplacement or modification is avoided. Thus, the preparation process is simplified greatly and the cost is lowered.

The present invention relates to a method for synthesizing high luminescence semiconductor quantum dots with a core-shell structure in a short time in large quantity. Using the method of synthesizing the quantum dots in accordance with the present invention, a large quantity of quantum dots can be economically synthesized in a rapid time without an explosion. And, the present invention can be applied to the fields employing various luminous materials since the luminous semiconductor quantum dots synthesized by the present invention has a high luminous efficiency and they can emit a light at various wavelengths in the whole range of a visible ray. And also, the present invention can be applied to a light emission device, a single electron transistor, a solar cell photo-sensitizer material and a bio-labelling tag since it is excellently stable.

A photoelectrode for producing hydrogen and oxygen by photoelectro-chemically decomposing water is characterized in that the photoelectrode is composed of a photocathode and a photoanode, wherein the photocathode and a photoanode are provide with quantum dots being assembled with assistance of a double-functional molecule. The invention achieves the establishment and the application of the photoelectrode for producing hydrogen and oxygen on the basis of semiconductors, quantum dots and catalysts. The photoelectrode is high in stability, is free of a sacrificial agent, is simple in operation, is good in repeatability, is strong in universality and is high in utilization rate on visible light. In addition, the catalyst is free of requirement of noble metals, is low in cost and is easy to obtain.

The invention relates to a wide band gap semiconductor nanotube/line array film characterized by high conversion efficiency and quantum dot sensitization, and a preparation method thereof as well as a photo-electrode adopting the wide band gap semiconductor nanotube/line array film. The wide band gap semiconductor nanotube/line array film provided by the invention comprises a wide band gap semiconductor nanotube/line array and a conductive substrate, and the wide band gap semiconductor nanotube/line array is filled with narrow band gap semiconductor quantum dot nano-particles. According to the preparation method provided by the invention, the anodic oxidation method is used for preparing the wide band gap semiconductor nanotube/line array film, and the chemical deposition method is used for preparing a narrow band semiconductor nanotube/line array film with sensitized quantum dots. The photo-electrode adopting the wide band gap semiconductor nanotube/line array film can be applied to a photo-chemical bath, and the photo conversion efficiency of the photo-chemical bath can be substantially improved. The invention can be widely applied to the technical field of photo-electricity conversion of solar power.

An infrared photodetector containing a region of semiconductor quantum dots (1), n type doped in the barrier region (2), and sandwiched between respective layers of semiconductors of n type (3) and p type (4). When infrared photons (5) are absorbed, they create electronic transitions (6) from the confined states in the dots (7) to the conduction band (8). This causes the appearance of a voltage between device p (9) and n (10) contacts or the production of an electrical current. In either way, the detection of the infrared light is possible. A low band-pass filter (12) prevents high energy photons (13) from entering the device and causing electronic transitions (14) from the valence (15) band to the conduction band (8).

The invention discloses a semiconductor resistance-type gas sensor and a preparation method thereof. The preparation method comprises the following steps: (1) coating a colloidal semiconductor quantum dot solution on an insulating substrate printed with electrodes, and forming a uniform film; (2) processing a quantum dot film by using a short-chain ligand solution; (3) removing the residual short-chain ligand and byproducts thereof; (4) repeating steps (1)-(3) for many times to obtain a colloidal semiconductor quantum dot film with a required thickness so as to complete preparation of the gas sensor. In the preparation method, the film can be formed on the insulating substrate directly, and the electrodes are prepared on the final colloidal semiconductor quantum dot film. The gas sensor comprises the insulating substrate, the electrodes and a gas-sensitive layer, wherein the gas-sensitive layer is the colloidal semiconductor quantum dot film. The gas sensor can detect instantaneous or subtle change of gas concentration at room temperature, and is high in response and restoration speed, high in sensitivity, safe and portable; therefore, the gas sensor has a good application prospect.

The invention relates to a polymer solar cell, which includes a transparent electrode, a donor material, an active layer material, a receptor material and a metal electrode, wherein a transparent base body which is covered by ITO (Indium Tin Oxide), FTO (Flouride-doped Tin Oxide), ATO (Arsenic Trioxide), graphene, carbon nanotubes or a conjugated polymer thin film is used by the transparent electrode; a nano composite material of conjugated polymer, a metal nanomaterial and a semiconductor quantum point nano material is adopted as the donor material; the active layer material is a nano composite material of conjugated polymer, graphene, carbon nanotubes or fullerene and derivatives thereof in the presence of a modifier; graphene, carbon nanotubes or fullerene and the derivatives thereof are adopted as the receptor material; and the metal electrode is made of silver paste, aluminum paste, silver aluminum paste or metal paste. The donor material, the active layer material, the receptor material and the metal paste are printed on the transparent electrode by using an ink printing machine in sequence, and are subjected to drying treatment at 50-100 DEG C in sequence to obtain the polymer solar cell. The cell has high utilization rate to sunshine, high carrier mobility, high compatibility of donor and receptor, high photoelectric conversion efficiency, simple and convenient preparation process and capability of realizing large-scale industrial application.

The invention discloses a single-photon source, which realizes the electrical injection with the photonic crystal micro cavity and the wafer bonding technology. The single-photon source comprises a bottom electrode, an n-shaped substrate, a lower DBR, a photonic crystal micro cavity, an upper DBR, a p-shaped contact layer and a top electrode, which are arranged in sequence from bottom to top; wherein, the photonic crystal micro cavity of the single-photon source is provided with semiconductor quantum dots; the air hole type photonic crystal defect cavity with a two-dimensional photonic lattice is adopted; the single-photon source realizes the combination of the photonic crystal micro cavity and the upper DBR by adopting the wafer bonding technology; and the electrodes of the single-photon source are evaporated on the upper surface of the p-shaped contact layer and the lower surface of the n-shaped substrate of the upper DBR. The single-photon source not only realizes the electrical injection, but also improves the emission efficiency of the single-photon source.

The present invention relates to a method of preparing a carbon nanotube-quantum dot conjugate having a high density of quantum dots (QDs) on its surface. This method involves providing a plurality of semiconductor quantum dots and providing a thiol-functionalized carbon nanotube having a plurality of terminal thiol groups on its surface. The plurality of semiconductor quantum dots are attached to the surface of the carbon nanotube under conditions effective to yield a carbon nanotube-quantum dot conjugate having a high density of quantum dots on its surface. The present invention also relates to a carbon nanotube-quantum dot conjugate having a high density of quantum dots on its surface. The present invention further relates to a photodetector device. This device includes a substrate and a nanocomposite layer. The nanocomposite layer includes a plurality of the carbon nanotube-quantum dot conjugates previously described.

The present invention relates to a solar cell having quantum dot nanowire array and the fabrication method thereof. The solar cell according to the present invention includes quantum dot nanowire array with a heterostructure including matrix and semiconductor quantum dots, and p-type and n-type semiconductor and electrodes each contacting the quantum dot nanowires. With the solar cell according to the present invention, the band gap energy of the semiconductor quantum dot can be easily controlled, the semiconductor quantum dots having different sizes are provided in the quantum dot nanowire so that the photoelectric conversion can be performed in the wide spectrum from visible rays to infrared rays, the quantum dot is embedded in the high density quantum dot nanowire array so that light absorption can be maximized, and the quantum dot nanowire contact p-type and n-type semiconductor over a wide area, conduction efficiency of electrons and holes can be improved.

The invention discloses a method for converting water solubility for reducing biotoxicity of a luminous quantum dot synthesized by an organic phase, which comprises the following steps of: dispersing the quantum dot into an organic solvent, then adding a silane reagent without a functional group into the solvent, allowing the silane reagent to be exchanged with a ligand on the surface of the quantum dot, wherein the concentration of the quantum dot in the organic solvent is 0.03 to 1.0mg/mL; preparing aqueous phase solution with a hydrophilic functional group; and mixing the quantum dot organic solvent and the aqueous phase solution with stirring to perform reaction to transfer the quantum dot to the aqueous phase solution. By using the converting method, the water-soluble quantum dot which is coated with a functionalized SiO2 outer shell, and has low biotoxicity and the diameter of less than or equal to 10nm is obtained; and the quantum dot has the characteristics of high biological adaptability, high fluorescence quantum efficiency, wide excitation band, narrow luminous spectrum, adjustable emitting color and the like.

The invention relates to a color battery assembly with a downward-transfer function for a spectrum, belonging to the technical field of solar photoelectric conversion. The color battery assembly comprises a solar battery array, the front area of the lighted surface of a battery slice of the solar battery array is provided with a spectrum downward-transfer optical medium layer; the spectrum downward-transfer optical medium layer absorbs a short wave range with poor battery spectrum response and transfers the short wave range with the poor battery spectrum response to a long wave range with ideal battery spectrum response and then carries out the photoelectric conversion through the battery slice; and the spectrum downward-transfer optical medium layer comprises a medium and semiconductor quantum dots, wherein the semiconductor quantum dots are uniformly dispersed in the medium, refer to nanoparticles of II-VI group compounds and have homogeneous or heterogeneous multi-layer structures. The color battery assembly is provided with common medium layers on the lighted surface and the backlight surface of the spectrum downward-transfer optical medium layer, enhances the response of the color battery assembly on short waves of a solar spectrum and effectively reduces the battery heat effect.