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.

An ultraviolet (UV) fluorometric sensor measures a chemical concentration in a sample based on the measured fluorescence of the sample. The sensor includes a controller, at least one UV light source, and at least one UV detector. The sensor emits UV light in a wavelength range of 245-265 nm from the light source through the sample in an analytical area. The UV detector measures the fluorescence emission from the sample. The controller transforms output signals from the UV detector into fluorescence values or optical densities for one or more wavelengths in the wavelength range of 265-340 nm. The controller calculates the chemical concentration of the chemical in the sample based on the measured fluorescence emissions.

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.

An ultraviolet (UV) detector for detecting and verifying the authenticity of documents placed therein and exposed to UV light and 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 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. Additionally, the detector housing includes an LED and translucent member disposed therein for providing diffuse visible white light for identifying watermarks on the documents. A user looks into the viewing chamber for viewing the UV activated features and watermarks on the documents.

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.

A device automatically actuated according to UV intensity includes a UV detector generating an electric signal indicative of a UV intensity of a light received thereby; a comparator in communication with the UV detector, receiving the electric signal to compare the UV intensity with a first threshold value, and asserting an actuating signal when the UV intensity is in a predetermined correlation with the first threshold value; and an actuated object in communication with the comparator, actuated to change a state thereof in response to the actuating signal. The actuated object can be an anti-glare rearview mirror, a sunshade curtain, a headlamp, or a transmittance-adjustable window of a vehicle. The actuated object can be a sunshade curtain or a transmittance-adjustable window of a building.

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.

A photovoltaic UV detector configured to generate an electrical output under UV irradiation. The photovoltaic UV detector comprises a first layer comprising an electrically polarized dielectric thin layer configured to generate a first electrical output under the UV irradiation; and a second, layer configured to form an electrical energy barrier at an interface between the second layer and the first layer so as to generate a second electrical output under the UV irradiation, the second electrical output having a same polarity as the first electrical output, the electrical output of the photovoltaic UV detector being a sum of at least the first electrical output and the second electrical output. The electrically polarized dielectric thin layer may be a ferroelectric thin film, which may comprise PZT or PZLT. The second layer may be a metal and the electrical energy barrier may be a Schottky barrier.

The invention provides a GaN semiconductor-based ultraviolet (UV) detector structure, from the substrate up, in sequence comprising n-type contact layer, light absorbing layer, light transmitting layer and p-type contact layer, all made of AlGaInN tetra-compound semiconductor material. By changing Al, Ga and In compositions of the semiconductor material, on one hand, these semiconductor layers can possess the needed energy gap, thus able to be specially sensitive to the optical reaction with respect to specific-wavelength UV; on the other hand, these semiconductor layers can possess matching crystal lattice constants, thus able to avoid the related problem of overlarge stress and simultaneously obtaining a UV detector with higher-quality crystal lattice structure. And the structure further comprises anode on the p-type contact layer, light transmitting Ohm contact layer and anti-reflecting layer as well as cathode on the n-type contact layer.

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 MgxZn1−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.

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.

The invention discloses an RP-HPLC detection method for the content of free polyethylene glycol in samples or products, which is characterized by making use of the non-polar difference of polyethylene glycol from other substances on the reversed-phase chromatography column and using UV detector combining evaporative light detector or diode array detector combining evaporative light detector signal contrast to screen signal peaks of free polyethylene glycol and to determine the content thereof by means of the external standard method. Based on the method, the invention also can be used for detecting the purity of polyethylene glycol modified products and the modification degree of modified products. The analysis method is highly sensitive, good in repetitiveness and selectivity, fast, efficient and simple, and is suitable for being used in the samples which have more complex components and are interfered in the polyethylene glycol-barium compound colorimetric determination provided by pharmacopoeia, especially suitable for being used in the polyethylene glycol modified samples or products.

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.

A method for detecting food additives in moon cakes, comprising the following steps: (1) preparing a mixed standard solution: mixing and preparing dehydroacetic acid, benzoic acid, sorbic acid, and four kinds of p-hydroxybenzoic acid lipid standard products in pure methanol; Acesulfame K, sodium saccharin, and 8 food coloring standards were mixed and prepared in pure water; then the above solutions were mixed in proportion to obtain a mixed standard stock solution; (2) sample extraction; (3) sample purification; (4) on Machine detection: the liquid to be tested and the mixed standard solution are placed in a liquid chromatograph equipped with an ultraviolet detector for detection, and the external standard method is used for quantification. Through gradient elution and wavelength switching, the content of food additives is measured simultaneously on the machine. The invention has the same pretreatment steps, low cost, high speed, reliable results and good reproducibility, and can simultaneously detect 17 kinds of food additives at one time.

A glare protection device for a welding protective mask includes an active electro-optical protective filter (2) and an electronic circuit (10). An UV-detector (UVD), which serves as an optical sensor, detects the welding light and, via an evaluation circuit (10.1), generates a signal (sin) for controlling of the protective filter (2). The signal corresponds to the detected UV intensity. The UV-detector includes a fluorescent layer (F) with an absorption in the UV range and an emission in the long-wave range corresponding to the spectral sensitivity of an assigned Si-photo detector (SD). This results in a simple and safe controlling of the protective filter, which is uninfluenced by the effects of extraneous light.

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.

A flame detection method capable of detecting a flame simply and effectively by using a UV detector having a comparatively small detection wavelength area. A plurality of spontaneously emitted light intensities having the same radical species but different wavelengths are measured respectively out of a spontaneously emitted light spectra of a UV area in the spontaneously emitted light components of a flame to determine emitted light intensity ratios that are mutual ratios between the measured spontaneously emitted light intensities with respective wavelengths, and a flame is detected based on the relations between those emitted light intensity ratios and flame temperatures or the relations between emitted light intensity ratios and air ratios of mixed air used for combustion. Especially, the OH zone spectrum of electron transition A<2>∑<+>->X<2>Pi from an excited state by combustion to a normal sate out of flame spontaneously emitted light components by lean combustion is measured, and emitted light intensity ratios between OH (2,0) in the vicinity of wavelength 260 nm, OH (1,0) in the vicinity of wavelength 280 nm, OH (2,1) in the vicinity of wavelength 287 nm, and OH (0,0) in the vicinity of wavelength 306 nm are determined to detect a flame state.