112 results about "Colloidal quantum dots" patented technology

The invention comprises an optoelectronic platform with a carbon-based conduction layer and a layer of colloidal quantum dots on top as light absorbing material. Photoconductive gain on the order of 106 is possible, while maintaining de operating voltage low. The platform can be used as a transistor.

The present invention is directed to light emitting devices including a first layer of a semiconductor material from the group of a p-type semiconductor and a n-type semiconductor, a layer of colloidal nanocrystals on the first layer of a semiconductor material, and, a second layer of a semiconductor material from the group of a p-type semiconductor and a n-type semiconductor on the layer of colloidal nanocrystals.

An optoelectronic apparatus, such as a photodetector apparatus comprising a substrate (1), a dielectric layer (2), a transport layer, and a photosensitizing layer (5). The transport layer comprises at least a 2-dimensional semiconductor layer (3), such as MoS2, and the photosensitizing layer (5) comprises colloidal quantum dots. Enhanced responsivity and extended spectral coverage are achieved with the disclosed structures.

The invention relates to a preparation method of a ZnO, CuO and ZnS quantum dot film. The preparation method comprises the following steps: preparing Cu ion modified ZnO quantum dot precipitate, CuO quantum dot precipitate and ZnS quantum dot precipitate; adding trichloromethane in the prepared quantum dot precipitates respectively to fully dissolve, then adding n-octylamine dispersant to obtain Cu ion modified ZnO colloidal quantum dot solution, CuO colloidal quantum dot solution and ZnS colloidal quantum dot solution; diluting the three kinds of colloidal quantum dot solutions with the sameamount of trichloromethane, filtering with a polytetrafluoroethylene (PTFE) filter, coating one or more of the colloidal quantum dot solutions on an indium-tin oxide (ITO) substrate through the spin-coating method, prebaking, and annealing in the air to obtain the quantum dot single-layer or multi-layer film. The preparation process of the invention is simple; the coated quantum dot film is compact and smooth and has good adhesion performance and controllable film thickness; and the quantum dot multi-layer structure is easy to realize and the quantum dot film is suitable for the multi-layer quantum dot film element.

Manipulation of the passivation ligands of colloidal quantum dots and use in QD electronics. A multi-step electrostatic process is described which creates bare QDs, followed by the formation of QD superlattice via electric and thermal stimulus. Colloidal QDs with original long ligands (i.e. oleic acid) are atomized, and loaded into a special designed tank to be washed, followed by another atomization step before entering the doping station. The final step is the deposition of bare QDs onto substrate and growth of QD superlattice. The method permits the formation of various photonic devices, such as single junction and tandem solar cells based on bare QD superlattice, photodetectors, and LEDs. The devices include a piezoelectric substrate with an electrode, and at least one layer of bare quantum dots comprising group IV-VI elements on the electrode, where the bare quantum dots have been stripped of outer-layer ligands.

The invention discloses an extensible semiconductor resistive flexible gas sensor with micro-wrinkle film structure and a preparation method thereof. Insulating substrate-polyacrylate double-sided foam tape (VHB, very high bond) that is extensible is unilaterally pre-extended to certain extent and fixed to a rigid substrate; a patterned graphene electrode and a colloidal quantum dot film are prepared on a VHB substrate that is pre-extended, and the sensor is prepared by retracting the VHB substrate slowly. The gas sensor prepared in the method has a gas-sensitive layer of micro-wrinkle film structure and a patterned graphene electrode, the gas sensor features extensibility, manufacturing temperature and operating temperature of the sensor can be lower than room temperature, transient or minor changes in gas concentration can be detected at room temperature, and the gas sensor has high response restoring speed and sensitivity, has certain resistance to ambient humidity interference and has better long-term stability.

The embodiment of the invention discloses an X-ray detecting panel and a preparation method thereof, relates to the field of detecting instruments, and provides the X-ray detecting panel with non-thallium-doped scintillator film layer as the scintillator. The injuries of thallium and iodide thereof to human bodies can be avoided, and meanwhile the preparation cost of the X-ray detecting panel is greatly reduced. The X-ray detecting panel comprises a lining substrate, a switch array arranged on the lining substrate, a photoelectric detector array arranged on the switch array, a cover plate, a scintillator film layer arranged on the cover plate, and a colloid quantum dot film layer arranged between the scintillator film layer and the photoelectric detector array, wherein the scintillator film layer is used for converting X-rays into near ultraviolet light, the colloid quantum dot film layer is used for converting near ultraviolet light converted by the scintillator film layer into visible light to be output, and the photoelectric detector array is used for converting the visible light converted by a wavelength converting unit into electric signals to be output.

The invention discloses a method for gluing quantum dot films and the quantum dot films. The method comprises the steps of preparing one or more layers of quantum dot films from colloidal quantum dots, volatilizing solvents in the quantum dot films after the films are formed, and forming the quantum dot films which only contain the quantum dots; putting the quantum dot films into a vacuum plasma generation cavity; and introducing H2 into the vacuum plasma generation cavity, then transforming the H2 into H plasma and gluing the quantum dot films through the H plasma. The quantum dot films are glued by use of HHIC and the process is improved, so that the quantum dot films have better effects of solvent resistance and mechanical force. The method for gluing the quantum dot films by HHIC is short in elapsed time, low in condition requirements and free of a special requirement on a reactant; and no new material is generated. Furthermore, the films glued by HHIC are better than traditional films which are glued in a heating manner in stability, and the electrical properties of the films are not changed. The application range and the material selection range of a solution method can be expanded by HHIC.

The invention discloses a red and green light perovskite quantum dot stable fluorescent powder based on SiO2 coating and a preparation method thereof and belongs to the field of luminescent materials;the method includes: 1) mixing, stirring and heating oleic acid, octadecene and Cs2CO3 to prepare a cesium oleate precursor solution; 2) with lead halide, oleylamine, oleic acid, and octadecene beingraw materials, heating and stirring the raw materials in a nitrogen atmosphere to prepare a lead halide precursor solution; 3) heating the lead halide precursor solution to a high temperature and injecting the cesium oleate precursor solution, and rapidly cooling the mixture to prepare a crude product of the perovskite quantum dots; 4) centrifuging and dispersing the crude product in n-hexane toobtain pure colloidal quantum dots, and adding metered (3-aminopropyl)triethoxysilane (APTES, similarly hereinafter) and mixing and stirring all the components to prepare the quantum dot stable fluorescent powder. The quantum dot stable fluorescent powder has high luminous efficiency and high color purity, has narrow emission peaks at 637 nm and 522 nm; after the SiO2 coating, the product is relatively stable.

A mechanically flexible array of optically pumped vertical cavity surface emitting lasers, fabricated using spin coating. The array uses InGaP colloidal quantum dots as an active medium and alternating polymer layers of different refractive indices as Bragg mirrors. Enhanced spontaneous emission is produced. The flexible array can be peeled off a substrate, producing a flexible structure that can conform to a wide variety of shapes, and having an emission spectrum that can be mechanically tuned. The flexible array can be used to create a flexible infrared light bandage.

The invention relates to a solar cell by virtue of taking colloid quantum dots and graphene as a light anode and a manufacturing method thereof and belongs to the field of photoelectric conversion, new energy materials and technologies. In the manufacturing method, ITO (indium tin oxide) is taken as a framework, and the graphene and the colloid quantum dots with the different grain sizes are deposited on the framework in sequence layer by layer to form a {graphene / quantum dots} laminated film which is taken as the light anode; mixtures of organic polymers are deposited on the light anode in afilm spinning mode; and finally vacuum evaporation is carried out on an electrode on the organic polymer film to finish the manufacturing of a solar cell device. The solar cell is simple and low in structure and manufacturing and can absorb the most of light energy of incident sunlight. The light anode is provided with the graphene film with high carrier mobility, thus greatly improving the extraction of photon-generated carriers to the electrode and the transmission process, thereby improving the photoelectric conversion efficiency of the solar cell.

The invention provides a preparation method of a colloidal quantum dot continuous laser. The preparation method comprises the steps that composite luminescent material of the perovskite quantum dot material and the polymer is formed on the corresponding surface of a resonant cavity through an in-situ method to act as gain medium. The invention also provides the colloidal quantum dot continuous laser comprising the gain medium which is used for receiving photons excited by continuous laser radiation; and the resonant cavity which is combined with the gain medium and used for amplifying the photons excited by the gain medium so as to output continuous laser, wherein the gain medium is the composite luminescent material of the perovskite quantum dot material and the polymer prepared through the in-situ method.

The invention discloses a sedimentation growing method of semiconductor nanocrystalline / quantum dots on a single crystal silicon material. The semiconductor nanocrystalline / quantum dot is composed of the materials with the following weight ratio: 1 to 100 parts of sulphur, selenium, sulfide or selenide, 1 to 100 parts of metal salt, 100-500 parts of solvent, 1-10 parts of coupling agent, a crystal silicon material and a silicon wafer. The crystal silicon material is taken as the matrix, colloidal quantum dots are composed in advance, then the coupling molecules are added, and the colloidal quantum dots are connected to the crystal silicon material through the spin coating and dispensing methods and the dip-coating technology. The semiconductor nanocrystalline / quantum dot has very stable physicochemical property, and the photoelectric conversion efficiency can not be influenced even though the quantum dot is exposed in air for a long time; and the preparation process is simple and easyto operate, the source of feed is abundant, and the quantum dot is easy for industrial applications, low in price and easy to be obtained.

The invention discloses a colloidal quantum dot-based strip metasurface-structured polarization-dependent narrowband detector and a preparation method thereof. The preparation method comprises the following steps of enabling a layer of silicon to be grown on a glass plate; performing spin coating of photoresist; transferring a strip array structure to perform developing treatment; performing photoresist removal; performing spin coating of quantum dots; and performing evaporation of a layer of gold by electron beam evaporation equipment. Based on the resonance effect of the strip array structure on the short-wave infrared specific wavelength, all absorption of light of specific wavelength is realized; by adjusting the geometrical structure parameters of the strip array structure, optical absorption is controlled to realize adjustment of specific wavelengths and absorption from visible light to infrared light; in addition, polarization dependence is achieved, and then the detector is prepared from the colloidal quantum dot material; and the preparation method is simple and easy, high in response, high in operability, and has wide application prospect.

The invention discloses a quantum dot fiber gas sensor and a preparation method thereof. The quantum dot fiber gas sensor comprises a fiber probe and a gas-sensitive layer comprising colloidal quantum dots, a refractive index sensitive area of the fiber probe is uniformly coated with the gas-sensitive layer, carrier concentration changes when the gas-sensitive layer of the fiber probe adsorbs gas, so that gas-sensitive layer refractive index change, optical fields in the fiber probe change, extinction ratio of spectrums change, the spectrums drift, gas concentration is obtained according to variation of the extinction ratio and the spectrums, the quantum dot fiber gas sensor has the advantages that the sensor is high gas-sensitive responsibility, distributed networking is easily achieved. According to the preparation method, the gas-sensitive layer is uniform and excellent in adhesive force and obtained by the aid of a layer-by-layer electrostatic self-assembly method, the thickness of the gas-sensitive layer can be adjusted, doping or surface decoration is achieved by the aid of short-chain ligand solution, adjusting and controlling are achieved according to characteristics of different target gases, and sensitivity and selectivity of the target gases are further improved.

The embodiment of the invention discloses an infrared detector, an infrared imager and a preparation method of the infrared detector. The infrared detector comprises at least one pixel, and the pixelcomprises a substrate layer, at least one laminated structure and a top electrode layer which are sequentially arranged from bottom to top; the laminated structure comprises an electrode layer and a quantum dot infrared absorption layer which are sequentially arranged from bottom to top; the quantum dot infrared absorption layer comprises a preset number of colloid quantum dots and is used for detecting infrared radiation; the wavelengths of infrared radiation detected by the quantum dot infrared absorption layers in different laminated structures are different. The infrared detector is simplein preparation process and low in cost; in addition, the wavelengths of infrared radiation detected by the quantum dot infrared absorption layers in different laminated structures are different, so infrared detection materials with different detection wavelengths are integrated on the same substrate structure, the detection range of the infrared detector can be better expanded, and the system performance is improved.

The invention provides a device structure and a manufacturing method thereof. The device structure is manufactured by utilizing quantum dots with a single dimension, emits light at a visible light waveband and a near-infrared waveband, and can generate laser. The manufacturing method comprises the following steps of: growing a zinc sulfide (ZnS) thin film on an indium zinc oxide (ITO) substrate; spin-coating cadmium selenide (CdSe) colloidal quantum dots on the ZnS thin film; growing another ZnS thin film and a metal electrode on the quantum dots; performing photoetching to form a device pattern; and performing packaging on the metal electrode to lead out a wire. The device structure has the light-emitting wavelengths of 450 to 850nm, and can emit visible light and near-infrared light on the basis of the surface defect state of the quantum dots, generate the laser by electrically exciting the population inversion of the energy level of the surface defect state, and be used for light-emitting diode (LED) white light illumination devices, laser devices and the like.

A Cd-free colloidal quantum dot which is a core particle that is coated with a shell made from a compound semiconductor and serves as a core for the shell, and emits visible fluorescence upon irradiation with excited light having a wavelength of a near ultraviolet region or a blue region. The colloidal quantum dot is represented by a chemical formula: A (B11-x, B2x) (wherein 0<x<1), has Zn as a Group-II element in the A site, Te as a Group-VI element in the B1 site, and Se or S as a Group-VI element in the B2 site, and has an average particle diameter of 1 nm or more and 10 nm or less.

The invention discloses a compound structure with a function of improving the wide-spectrum light absorption efficiency. The compound structure comprises absorbing layers and reflecting layers which are compounded with one another. The absorbing layers are of photonic crystal structures, and periodic triangular grooves in the surfaces of nonmetal materials are filled with thin polymer films or thin films with colloidal quantum dots to form the photonic crystal structures; metal materials are coated on the surfaces of random triangular grooves in the bottom surfaces of the nonmetal materials to form the reflecting layers. The compound structure has the advantages that efficient absorption of broadband and wide-angle solar energy in wavebands which cover the ranges from ultraviolet waves to infrared waves can be improved by the aid of the compound structure, the infrared wavebands exceed Yablonovitch limit, electric fields in the triangular grooves in the surfaces of the absorbing layers and in cavities formed by the reflecting layers and the triangular grooves in the surfaces of the absorbing layers can be greatly strengthened, and the compound structure has an excellent application prospect in the aspects of solar cells, photoelectric detection, military stealth and the like.

Manipulation of the passivation ligands of colloidal quantum dots and use in QD electronics. A multi-step electrostatic process is described which creates bare QDs, followed by the formation of QD superlattice via electric and thermal stimulus. Colloidal QDs with original long ligands (i.e. oleic acid) are atomized, and loaded into a special designed tank to be washed, followed by another atomization step before entering the doping station. The final step is the deposition of bare QDs onto substrate and growth of QD superlattice. The method permits the formation of various photonic devices, such as single junction and tandem solar cells based on bare QD superlattice, photodetectors, and LEDs. The devices include a piezoelectric substrate with an electrode, and at least one layer of bare quantum dots comprising group IV-VI elements on the electrode, where the bare quantum dots have been stripped of outer-layer ligands.

The invention discloses a colloid quantum dot infrared focal plane array based on an interference enhancement structure. The colloid quantum dot infrared focal plane array comprises a quantum dot pixel layer and the interference enhancement structure, the quantum dot pixel layer comprises a common electrode layer, an infrared quantum dot film layer and a semi-transparent counter electrode layer; the interference enhancement structure comprises an optical isolation layer and a reflection electrode layer. The novel colloidal quantum dot is used as a photosensitive material, and has the advantages of high sensitivity and low cost; an interference enhancement structure is added to gather infrared rays with specific wavelengths, so that light response is improved; quick light response is realized, and the response time is less than 20 nanoseconds; colloid quantum dots can be synthesized in a large-scale liquid phase, and the cost is greatly reduced.

The invention belongs to synthesis of semiconductor nanoparticles, and particularly relates to a preparation method of lead sulfide colloidal quantum dots. The preparation method disclosed by the invention comprises the following steps: heating submicron basic lead chloride as a lead source synthesized by an aqueous solution precipitation method and an organic reagent to form a lead precursor solution, then injecting the elemental sulfur solution dissolved in oleylamine into the lead precursor solution at a specific temperature to react for 0.5-20 minutes to obtain a lead sulfide colloidal quantum dot stock solution, and finally, carrying out impurity removal and anti-solvent purification to obtain the lead sulfide colloidal quantum dot solution. The preparation method disclosed by the invention has the advantages of good controllability, stable chemical properties of reactant raw materials, high fluorescence efficiency of reaction products and the like, and is suitable for batch synthesis of high-quality lead sulfide colloidal quantum dots.

Differing from commercial solution of colloidal quantum dots being often composed of a non-polar organic solvent and a plurality of quantum dots, the present invention discloses a combination solution of colloidal quantum dots comprising a liquid monomer with low glass transition temperature and a plurality of quantum dot units, wherein the quantum dot unit comprises a polar carrier particle, a plurality of quantum dots and an enclosure layer with high glass transition temperature. It is worth explaining that, after applying an aging treatment to the combination solution of colloidal quantum dots and the commercial solution of colloidal quantum dots for 200 minutes, measurement data of UV-VIS spectrophotometer have proved that the combination solution of colloidal quantum dots provided by the present invention is 1.6 times as stable as the commercial solution of colloidal quantum dots.

The invention discloses a preparation method of a colloidal quantum dot fluorescent powder composite film. The method includes: firstly preparing a graphene and carbon nanotube composite film and colloidal quantum dot fluorescent powder; then mixing the colloidal quantum dot fluorescent powder with hydroxyl polydimethylsiloxane, dimethyl silicone oil, white carbon black, hexamethyldisiloxane and modified carbon nanotubes, slowly raising the temperature to 90-120DEG C, maintaining the state for 1-4h, conducting cooling and filtering to obtain A; then mixing dimethyl diethoxysilane, dimethyl silicone oil, vinyltriethoxysilane and dibutyltin dilaurate evenly, conducting stirring in a closed reaction kettle for 1-2h at room temperature, and then performing filtering to obtain B; and finally mixing A and B according to a mass ratio of (9-11):1, coating the graphene and carbon nanotube composite film with the mixture by a spin coater, and then conducting curing for 2-4h. The method provided by the invention can take the graphene and carbon nanotube composite high thermal conductive film as the carrier to prepare the colloidal quantum dot fluorescent powder composite film.

The invention discloses a QCM (quartz crystal microbalance)-based chemical sensor and a preparation method thereof. The chemical sensor comprises a quartz crystal oscillating sheet and a sensitive layer; the quartz crystal oscillating sheet is coated with the sensitive layer; and the materials of the sensitive layer are quantum dots or quantum lines. The surface of the quartz crystal oscillator iscoated with colloidal quantum dots or quantum lines uniformly to form a film and ligand treatment is conducted by a proper salt solution, so that the long-chain ligand on the surface of each quantumdot or quantum line is removed. Compared with the existing QCM chemical sensor, the QCM chemical sensor taking the colloidal quantum dots or quantum lines as the sensitive layer has the following advantages: the sensitive layer can form a film at a room temperature and has high crystallinity, the process is simple and convenient, high specific surface area and activity of the nanometer material can be maintained in devices, response and recovery time is quick, and the response is fast.

The embodiment of the invention provides an infrared detector, an infrared imager and a preparation method of the infrared detector, and the infrared detector comprises a substrate layer which can transmit infrared radiation of a preset infrared radiation band; a first electrode layer formed on the substrate layer; and one infrared detection unit formed on the first electrode layer or at least twoinfrared detection units which are arranged at an interval, wherein each infrared detection unit comprises an infrared absorption layer formed on the first electrode layer and a second electrode layer formed on the infrared absorption layer, and a preset number of colloid quantum dots are arranged in the infrared absorption layer. The preparation process of the infrared detector is simple, the cost is low, the infrared detector is not limited by epitaxial equipment at all, and infrared absorption layers of various sizes can be prepared according to requirements, so the wavelength of infraredradiation capable of being detected by the infrared detector is flexible and adjustable, and the universality is high.

A silicon-based near-infrared quantum-dot electroluminescent device comprises a substrate, an oxidation layer, a light-emitting layer, an electron transporting layer and a metal electrode, wherein the oxidation layer which is a silicon dioxide film is prepared on the substrate and is used for balancing electron and hole injection by means of voltage sharing; the light-emitting layer is prepared on the oxidation layer and is composed of near-infrared light-emitting colloidal quantum dots; the electron transporting layer is prepared on the light-emitting layer and can transport electrons and improve carrier injection efficiency; and the metal electrode is prepared on the electron transporting layer and used for injecting electrons into the light-emitting layer. Each of the substrate, the oxidation layer, the light-emitting layer, the electron transporting layer and the metal electrode is of a planar waveguide structure or a ridge waveguide structure, the substrate of the ridge waveguide structure is convex, a boss is arranged in the middle of the substrate, and the oxidation layer, the light-emitting layer, the electron transporting layer and the metal electrode are all prepared on the boss of the substrate. The silicon-based near-infrared quantum-dot electroluminescent device is tunable in light-emitting frequency, and the preparation method is available to materials, low in production cost and simple in process.

The invention relates to an all-inorganic quantum-dot light emitting diode. A positive electrode, a light emitting layer, an electron transmission layer and a negative electrode are sequentially superposed on the light emitting diode. A TiO2-x film with n-typed semiconductor defects and a colloidal quantum-dot light emitting layer with p-typed semiconductor defects are adopted. When bias voltage is added to the positive and negative electrodes, p-n junction excitons can be generated at the positions of the interfaces of the electron transmission layer and the light emitting layer. On one hand, transmission efficiency of current carrier electrons can be effectively improved by adopting TiO2-x as the electron transmission layer, on the other hand, inhibition of hole-free transmission layer on light emitting of the excitons can be decreased to a large extent, and electro-optical conversion efficiency of the quantum-dot light emitting diode can be greatly improved.