240 results about "Uv detector" patented technology

A novel method for fabrication of hybrid semiconductor-graphene nanostructures in large scale by floating graphene sheets on the surface of a solution is provided. Using this approach, crystalline ZnO nano/micro-rod bundles on graphene fabricated using chemical vapor deposition were prepared. UV detectors fabricated using the as-prepared hybrid ZnO-graphene nano-structure with graphene being one of the two electrodes show high sensitivity to ultraviolet light, suggesting the graphene remained intact during the ZnO growth. This growth process provides a low-cost and robust scheme for large-scale fabrication of semiconductor nanostructures on graphene and may be applied for synthesis of a variety of hybrid semiconductor-graphene nano-structures demanded for optoelectronic applications including photovoltaics, photodetection, and photocatalysis.

The invention relates to processes for the synthesis of 2-D and 3-D periodic porous silicon structures and composites with improved properties having the advantages of porous silicon and photonic bandgap materials. Photonic crystals comprise a two dimensionally periodic or three dimensionally periodic microporous structural matrix of interconnecting, crystallographically oriented, monodispersed members having voids between adjacent members, and said members additionally having randomly nanoporous surface porosity. The silicon nanofoam material shows enhanced and spectrally controlled/tunable photoluminescence and electroluminesce and finds use as transparent electrodes, high-lumonosity light emitting diodes (LEDs), wavelength division multiplexors, high-active-area catalyst supports, photonic bandgap lasers, silicon-based UV detectors, displays, gas sensors, and the like.

An ultraviolet (UV) detector for detecting and verifying the authenticity of documents placed therein and exposed to ultraviolet light and ambient (white light) backlighting. The UV detector includes a detector housing, and a viewing chamber having a viewing mirror mounted therein for viewing documents. The detector housing also includes a document insertion slot for inserting documents into the viewing chamber adjacent to the viewing mirror. The detector housing further includes an LED holder for holding one or more LED's therein to provide a source of UV light in the viewing chamber which is transmitted to the viewing mirror and to the documents for identifying UV activated features on the documents, including UV holographic images and/or UV activated inks on the documents that are illuminated. The user looks into the viewing chamber for viewing the UV activated features on the viewing mirror. Additionally, the detector housing includes a translucent member disposed therein for diffusing visible white light. The UV detector includes a printed circuit board (PCB) for holding at least one LED to provide a source of visible white light in the detector housing which is transmitted to the translucent member for diffusing the visible white light for identifying watermarks on the documents that are illuminated. The user looks into the viewing chamber at the viewing mirror which reflects the identified watermarks to the user. Also, the placement of the viewing mirror increases the illumination area of the 365 nm UV light source in order to reduce the size of the detector housing.

A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.

Described herein is device configured to be a solar-blind UV detector comprising a substrate; a plurality of pixels; a plurality of nanowires in each of the plurality of pixel, wherein the plurality of nanowires extend essentially perpendicularly from the substrate.

The invention belongs to the field of semiconductor optoelectronic detectors, in particular relates to a back incident-type UV detector with quartz as a substrate, nano-TiO2 thin film as a basic UV detection material and Ni as a metal electrode, and a preparation method thereof. The detector takes the quartz as the substrate and adopts an M-S-M (metal-semiconductor-metal) structure. The method for manufacturing the UV detector comprises the steps of adopting a sol-gel technique to grow a TiO2 nanometer thin film on the quartz substrate, evaporating a layer of thin Ni on the prepared TiO2 thin film by a magnetron sputtering method to achieve electrode contact, and adopting lithography technology to obtain Ni inserted-finger shape electrodes. The UV detector in an MSM planar double schottky barrier structure adopts a back incident-type working mode and can greatly improve responsiveness. The detector has good detection performance for the UV rays 250 to 350 nm in wavelength.

The invention discloses a fire hazard alarm safety protection system and method based on a UV and image detection technology. Detected UV radiation data of a monitored area is received, the safety state of the monitored area is pre-determined, and whether UV waveband data carried by flames exist is determined; and image data of the monitored area and a UV data analysis results are received, when it is determined that the UV waveband data carried by the flames exist, the image data is identified, and whether a fire hazard is generated is determined. A UV detector and a monitoring pick-up head are compounded together, under a normal condition, the monitoring pick-up head only carries out normal safety monitoring work, and an image identification algorithm is not started for secondary determination unless the UV detector detects fire hazard signals. A two-stage fire hazard detection mechanism is employed, the correct rate of fire hazard identification is improved, useless calculation of a computer is also reduced, and waste of resources is avoided.

A UV detector has a UV detection thin film of coated spherical silicon nanoparticles formed upon a substrate. The detector includes structures to bias the thin film. In preferred embodiments, a thin conductor that is at least semi-transparent to UV radiation is formed over the thin film. In preferred embodiments, the UV detector is formed as a silicon based integration, upon a device quality silicon wafer.

An ultraviolet light sensor includes an elongated metal oxide nanostructure, a layer of an ultraviolet light-absorbing polymer, a current source and a current detector. The elongated metal oxide nanostructure has a first end and an opposite second end. The layer of an ultraviolet light-absorbing polymer is disposed about at least a portion of the metal oxide nanostructure. The current source is configured to provide electrons to the first end of the metal oxide nanostructure. The current detector is configured to detect an amount of current flowing through the metal oxide nanostructure. The amount of current flowing through the metal oxide nanostructure corresponds to an amount of ultraviolet light impinging on the metal oxide nanostructure.

The invention relates to and provides an ultraviolet (UV) detector of an inorganic perovskite phototransistor structure. A substrate (1) is a glass substrate, a CsPbX3 thin film (2) is prepared on thesubstrate (1) as an active layer, a PMMA organic layer (4) doped with CsPbX3 quantum dots (5) is prepared by the same material on the surface of the CsPbX3 thin film (2) as a gate insulating layer, and the CsPbX3 quantum dots are taken as a UV light sensing window; a source electrode (3.1) and a drain Au electrode (3.2) of the thin film transistor are respectively located on two sides of the CsPbX3 thin film (2), an FTO gate electrode (6) is located in the middle on the CsPbX3 thin film (2), and the integrated function of photo-generated carrier separation, converted electrical signal readingand amplification is obtained under the modulation of the source electrode (3.1), the drain Au electrode (3.2) and the FTO gate (6) of the thin film transistor, so as to achieve high response UV signal detection. The phototransistor detector can adopt a top-gate structure as shown in FIG.1 or a bottom-gate structure as shown in FIG.2. The above two structures can be prepared on the glass substrate and also be prepared on a flexible substrate to form the flexible phototransistor UV detector of the bottom-gate or top-gate structure.

The invention provides a UV detector and a preparation method thereof. The UV detector comprises a substrate. The substrate is successively provided with an n-type layer, an i-type superlattice multiplication layer, an i-type photosensitive absorption layer and a p-type layer. The n-type layer is provided with an n-type Ohmic electrode, the p-type layer is provided with a p-type Ohmic electrode, and the i-type superlattice multiplication layer is a superlattice of group-III nitrides. According to the invention, the problem of difficulty in detecting weak ultraviolet light due to UV detector insensitivity caused by similar ionization coefficients of electrons and cavities by use of a conventional UV detector in the prior art is solved.

Photoconductive devices (1,2) comprising Mg_xZn_1−xO, that is preferably epitaxially deposited on a substrate (21), optionally also including a buffer layer (22), wherein x has a value such that the layer is sensitive to UV light. The a MgZnO device (2) having predetermined electrical and optical properties and first and second electrodes (3) deposited on a surface of the device, the second electrode being spaced from the first electrode. A voltage source (4) is connected across the first and second electrodes to create an electric field within the device. In operation, when the surface of the device upon which the electrodes are deposited is subjected to a photon emission, electron-hole pairs are created within the device and flow within the device because of the electric field.

The invention belongs to the field of semiconductor photoelectric material technology and relates to a method for growing an MgxZn1-xO film by electron beam evaporation. A composite target formed by sintering polycrystalline MgO and ZnO powder is evaporated by electron beam heating by electron beam evaporating equipment and is deposed on a substrate to form the MgxZn1-xO semiconductor alloy thin film. The invention has simple preparation process and low cost, and is suitable for preparing thin film used for UV detectors with wavelength of 280 to 220 nm.

The present invention provides a detection method of parecoxib sodium genotoxicity impurity and application thereof. The method uses a reversed-phase liquid chromatography method. The chromatography conditions are as follows: the chromatographic column comprise a C18 column, a C8 column, a phenyl column and a Hilic column; a mobile phase consists of water-acetonitrile, dilute phosphoric acid-acetonitrile, and phosphate-acetonitrile; a flow phase comprises an aqueous phase and an organic phase in the ratio of 90:10-10:90; the column temperature is 25-40 DEG C; the flow rate of the mobile phase is 0.2-2ml / min; detection wavelength is 205-290nm; a detector is a UV detector or a photodiode array (PDA) detector; and the sample size is 0.1-40 mul. The detection method of parecoxib sodium genotoxicity impurity achieves the separation of parecoxib sodium and three genotoxicity impurities in a short period of time, has high sensitivity and specificity, and simple operation, reaches the separation rate of the main component and genotoxicity impurities, and the separation rate of genotoxicity impurities both greater than 1.5; and the method can be used for quality control of parecoxib sodium, and has practical value.

A customizable high-gain ZnO nanowire array UV detector and a preparation method thereof relate to the fields of microelectronic technologies, nanometer technologies and UV detection. On the basis of a synergic theory, nanowires compete for a reaction solute when fluctuation is instable, an in such a competition mechanism, the thinner a seed layer is, the fewer solute resources are needed, and growth time is decided by the growth speed. Based on such a growing principle, the thickness of the seed layer, the solution concentration and growth time are adjusted to obtain nanowires of higher quality, and UV detection devices of different gains are obtained. The method is simple and effective, and the customized devices of different gains can be suitable for UV detection in different environments.

The invention discloses a preparation method for a ZnO nanocrystalline thin-film transistor type UV detector. The UV detector successively comprises a low-resistance Si layer, a SiO2 insulating layer, a ZnO nanocrystalline layer and an Au electrode from bottom to top. The preparation method comprises the steps of firstly, preparing a ZnO nanocrystalline colloid dispersed phase; secondly, conducting the spin coating process of the colloid dispersed phase on the SiO2 surface of Si/SiO2, and then annealing; finally, plating the Au electrode to complete the preparation of the UV detector. Compared with a traditional UV detector, the above UV detector prepared through the above method is low in dark current, high in response sensitivity, quick in response time, simple in structure and low in manufacturing cost. Therefore, the method has an important application value in the fields of military, civilian and special aspects.

The invention discloses a UV detector with a non-polar absorption layer, which comprises the following elements arranged from the bottom to the top in a successive manner: a substrate, an AlN intermediate layer, an un-doped AlGaN buffer layer, an n-type AlGaN layer and a non-polar AlxGa1-xN/AlyGa1-yN multiple quantum well absorption and isolation layer, an un-doped ALzGa1-zN multiplier layer, p-type AlGaN layer, a p-type Ohmic electrode provided on the p-type AlGaN layer, an n-type Ohmic electrode arranged on the n-type AlGaN layer, where the AlxGa1-xN/AlyGa1-yN multiple quantum well is used as the absorption layer of the UV detector. The beneficial effects of the present invention are: to fundamentally prevent the polarized electric field in the absorption layer from compensating the built-in electric field in the p-n junction and to improve the photocurrent of the ultraviolet detector; in addition, the use of the non-polar AlxGa1-xN/AlyGa1-yN multiple quantum well as the absorption layer of the UV detector can further enhance the UV absorption coefficient and lateral carrier mobility of the UV detector due to the action of the quantum effect and plays an important role in raising the quantum efficiency and the sensitivity of the UV detector.

The present invention relates to a method for detecting vanillylmandelic acid in human urine. The method comprises: taking human urine, and carrying out acidification corrosion protection with HCl so as to long-timely store at a temperature of -80 DEG C; extracting the urine with ethyl acetate, volatilizing, dissolving with acetic acid, and carrying out other processes so as to obtain a VMA crude extract; and separating the crude extract through HPLC, obtaining the stable and single VMA absorption peak through a UV detector at a wavelength of 280 nm, drawing a VMA standard curve through an external standard method, and finally calculating the VMA content. The method of the present invention has characteristics of low cost and easy operation, and provides a rapid, inexpensive and sensitive method for detecting VMA in human urine.