684 results about "Dark current" patented technology

The invention relates to the technical field of gas leakage detection, and discloses an infrared imaging radiation correction method and system for gas leakage detection, and the method comprises the steps: obtaining the distribution data of dark current noise, and the mapping relation parameters of an image gray value and a radiation brightness value; acquiring infrared radiation of the gas leakage scene by using an infrared detector to obtain an original infrared image; based on the distribution data of the dark current noise, performing pixel-by-pixel compensation on the original infrared image to generate an infrared image after dark current correction; extracting the radiation intensity distribution of the infrared image after dark current correction, calibrating the radiation value of each pixel in the infrared image based on the mapping relation parameter between the image gray value and the absolute radiation brightness value, converting the image gray value into the absolute radiation brightness value, and generating the infrared image after radiation calibration; and outputting an infrared image after radiometric calibration for subsequent gas leakage area identification and feature analysis. According to the invention, a high-quality and quantifiable radiation quantification image can be output.

The invention discloses a multispectral pollution analysis method and system for a photovoltaic cleaning unmanned aerial vehicle, and belongs to the technical field of spectrum detection.The multispectral pollution analysis method comprises the steps that a multispectral image is obtained, dark current-radiation-atmosphere-shadow full-link preprocessing is carried out, multiband weighted threshold segmentation and morphological post-processing are constructed, and a pollution area is extracted; establishing a self-learning pollution spectral feature library, and identifying pollution types by using cosine similarity; generating a pollution degree distribution diagram in combination with the pollution type-efficiency attenuation mapping table; and when the overall efficiency loss exceeds a preset value, planning a three-dimensional track based on a cluster priority score and an ant colony-genetic fusion algorithm, and returning an image to perform closed-loop verification and complementary cleaning after the unmanned aerial vehicle performs cleaning. According to the invention, the pollution identification precision, the efficiency evaluation accuracy and the cleaning intelligence level are significantly improved, and the method can be widely applied to unattended operation and maintenance of the photovoltaic power station.

The invention provides a preparation method of a barrier type antimonide infrared detector. The preparation method comprises the following steps: selecting a gallium antimonide substrate; a gallium antimonide buffer layer, an indium arsenide heavily-doped layer, a class II superlattice absorption layer and an aluminum-arsenic-antimony barrier layer are sequentially grown on the substrate in an epitaxial mode through a molecular beam epitaxy method; mechanically stripping the hexagonal boron nitride two-dimensional material, and transferring the stripped hexagonal boron nitride to the aluminum-arsenic-antimony barrier layer to form a Van der Waals heterojunction and composite barrier layer structure; depositing electrodes by using an ultraviolet lithography technology and a thermal evaporation mode to form one electrode arranged on the gallium antimonide buffer layer and the other electrode arranged on the boron nitride; a large-numerical-aperture micro-lens array is processed on a substrate, and the micro-lens array is composed of gallium antimonide cylinders with a phase modulation function; therefore, the antimonide medium-wave infrared detector with the composite barrier layer can be formed, the quantum efficiency is improved, the order of magnitude of dark current is reduced, and room-temperature medium-wave infrared detection can be realized.

The invention discloses an engine oil carbon deposition sampling detection method and system based on multispectral imaging, and the method comprises the steps: carrying out the collection of a to-be-processed multispectral image of an engine oil sample under a multispectral light source, and carrying out the preprocessing of the image to obtain a to-be-processed image; performing dark current correction on the to-be-processed image according to a band ratio method, and enhancing the signal intensity of the to-be-processed image; calculating the spectral reflectivity of the to-be-processed image according to the signal intensity of the to-be-processed image; extracting a three-dimensional feature tensor in the to-be-processed image according to the spectral reflectivity; segmenting the to-be-processed image according to the three-dimensional feature tensor, and screening a carbon deposition region; calculating a carbon deposition probability value of each pixel point in the carbon deposition area according to the spectral reflectivity; and setting a carbon deposition threshold value according to the carbon deposition probability value for judgment so as to judge whether carbon deposition exists in the engine oil sample or not. The similarity between the sample engine oil spectral reflectivity and the reference engine oil is reflected, and a possible carbon deposition area is found, so that the carbon deposition defect is accurately judged and identified.

The invention discloses a stress balance InP-InGaAs avalanche photodetector and a preparation method thereof. An n-type InP buffer layer, an unintentionally doped In < 0.53 > Ga < 0.47 > As bottom absorption layer, a plurality of groups of unintentionally doped stress matching InGaAs absorption layers, an unintentionally doped In < 0.53 > Ga < 0.47 > As top absorption layer, an n-type InP charge layer and an unintentionally doped InP cover layer are sequentially grown on an n-type InP substrate; the optimal photosensitive wavelength of the avalanche photodetector is 2.0 microns, and the device can stably work at room temperature at low dark current.

The invention discloses a dynamic adaptive black level correction method and device, and relates to the technical field of image processing. According to the dark current space distribution difference, an effective pixel area in each frame of original image is dynamically divided; determining an initial black level calibration coefficient of each space block based on the dark pixel noise level; obtaining the current temperature and the temperature change rate of each space block, and obtaining the level calibration coefficient of each space block after temperature self-adaptive calibration based on the initial black level calibration coefficient corresponding to each space block; fusing the calibration information of the previous frame and the level calibration coefficient of the current frame to obtain a cross-frame stable calibration result; and correcting the effective pixels in each space block based on a cross-frame stable calibration result to obtain a corrected pixel value, and reconstructing the corrected pixel value into an output image. The problems that an existing black level calibration technology is poor in space uniformity, insufficient in temperature change adaptability and unstable in calibration coefficient are solved.

The invention relates to a method for verifying a Mars sky radiance simulation result based on a Mars real-shot photo, and belongs to the technical field of Mars sky background radiance. Comprises: image acquisition; performing radiation calibration; correcting dark current; performing flat field correction; converting a radiation value; and geometric correction. The Mars sky radiance simulation method breaks through the dependence of an existing model on idealized hypothesis, performs dynamic verification by using actual shot image data, remarkably improves the authenticity and reliability of a Mars sky radiance simulation result, and effectively solves the problem of systematic deviation under a specific wave band; by constructing a complete process from image acquisition, radiation calibration, geometric modeling to brightness inversion and comparison verification, dynamic feedback and closed-loop correction of a theoretical radiation model are realized, model adaptability is improved, and fine modeling under multi-temporal and multi-meteorological conditions is supported; the method can be applied to an existing Mars rover navigation camera and an image processing link of the Mars rover navigation camera, does not need additional modification, has good engineering practicability and task compatibility, and is convenient to popularize and apply.

The invention belongs to the technical field of image processing, and particularly relates to an intelligent agricultural product pesticide residue detection method and system based on a spectrum technology, and the method comprises the steps: obtaining the hyperspectral reflectivity according to the original hyperspectrum, dark current and whiteboard image data; calculating an illumination confidence factor by using the average spectral intensity; performing linear scaling on the obtained standard biological matrix background spectrum according to the illumination confidence factor to obtain a local background estimated value and obtain a net residual spectrum; generating a pesticide residue distribution thermodynamic diagram by combining the cosine similarity of the net residual spectrum and the target pesticide standard fingerprint spectrum and the noise suppression weight based on the illumination confidence factor; and pesticide residue detection is carried out according to the statistical characteristics of the connected region of the suspected defect mask. Through adaptive background deduction and noise suppression, the problems of uneven curved surface illumination and strong background interference are solved, and the detection accuracy is improved.

The invention discloses a detection method for fertilizer production, and relates to the technical field of fertilizer detection.The detection method comprises the following steps that a near-infrared multispectral visual detection system is installed at the working section before packaging of a fertilizer production line, the positions of a camera and an illumination source are adjusted, and multispectral images of fertilizer particles are collected; sequentially carrying out dark current correction and flat field correction on the acquired image, eliminating noise and uneven illumination, and then carrying out median filtering to remove random noise; selecting a waveband image with the best contrast ratio, separating particles from the background through threshold segmentation, and positioning each independent particle after optimizing the boundary through morphological processing; and based on the multi-band reflectivity difference, analyzing the surface material of the particles pixel by pixel, and counting the proportion of the coating area of each particle to obtain the coating coverage rate of the single particle. By introducing the near-infrared multispectral visual detection technology and the coating uniformity quantitative analysis model, non-destructive and high-precision online detection of the coating coverage rate of the fertilizer can be realized.

The invention provides a polarization hyperspectral water quality monitoring system and method, and the system comprises a tower footing polarization hyperspectral imaging module which is disposed on a building beside a to-be-detected water area, and carries out the area array staring scanning of the to-be-detected water area through a polarization hyperspectral imager, so as to obtain a water body polarization hyperspectral image signal of the to-be-detected water area; the image spectral data processing module is used for deducting dark current and spurious signals from the water body polarization hyperspectral image signals, and calculating the water body spectral reflectivity of the water area to be measured according to the water body polarization hyperspectral image signals by combining a gray value and reflectivity relation model constructed by using the hyperspectral image signals of the gray scale calibration plate; and the water quality parameter spatial distribution inversion module is used for performing inversion on the to-be-detected water quality parameters of the to-be-detected water area according to a pre-constructed water quality parameter inversion model and the water body spectral reflectivity. According to the technical scheme, the integration level is high, the automation degree is high, rapid deployment can be achieved, and all-day continuous unattended monitoring can be achieved.

The invention discloses a black silicon broadband photoelectric detector based on alternating current photovoltaic effect optimization. The device comprises an alternating-current photovoltaic effect unit, a core light absorption layer, a heterostructure building layer, a top electrode and a bottom electrode, the alternating-current photovoltaic effect unit is used for generating a periodic flash field, irradiating the periodic flash field on the surface state of the heterogeneous pn junction to capture or release transient charges, and collecting the transient charges to perform ultra-high-sensitivity optical detection; the core light absorption layer is made of a black silicon material and is used for improving light absorption through a surface micro-nano structure, widening the light absorption range and providing a surface state as an active site for capturing or releasing transient charges in an alternating current photovoltaic effect; the heterostructure layer and the core light absorption layer form a heterogeneous pn junction so as to construct a built-in electric field to promote generation, separation, migration and recombination of carriers. According to the invention, the characteristics of wide spectral response, ultrahigh sensitivity, low dark current and zero-bias working can be realized, high-precision detection can be carried out under weak light, and the development of high-precision technology is facilitated.

The invention belongs to the technical field of two-dimensional material photoelectric devices, and particularly relates to a Van der Waals heterojunction with a unipolar barrier and polarization sensitivity and application of the Van der Waals heterojunction. A p-type material Ta2NiSe5 with anisotropy is used as a collection layer of a bottom layer carrier, an n-type material ReS2 with anisotropy is used as an upper light absorption layer, WSe2 is used as a middle barrier layer, a Van der Waals heterojunction with a unipolar barrier and polarization sensitivity is constructed, and then the photoelectric detector is prepared. The photoelectric detector made of the constructed Van der Waals heterojunction has the characteristics of low dark current, high detection rate, wide band and polarized light response.

The invention provides an etching method of a double-color second-class superlattice infrared detector, and belongs to the technical field of chip manufacturing. The method comprises the following steps: providing a double-color second-class superlattice infrared detector, and forming a photoresist mask on the surface of the double-color second-class superlattice infrared detector; under the condition that the ratio of the longitudinal etching rate to the transverse etching rate is not less than 5: 1, performing dry etching on the surface of the double-color second-class superlattice infrared detector to obtain an initial mesa structure; the initial mesa structure is subjected to wet etching, a middle mesa structure is obtained, the wet etching time is smaller than or equal to 2 min, and the wet etching temperature is smaller than or equal to 10 DEG C; and post-processing the middle table-board structure to obtain the table-board structure. Through organic combination of a high-anisotropy forming effect of dry etching and a low-damage repairing effect of wet etching, the low surface damage characteristic is considered while high aspect ratio etching is realized, the dark current of the device is fundamentally reduced, and the intrinsic detection performance of the device is improved.

The invention provides a distributed optical fiber temperature measurement method and device, electronic equipment and a storage medium, and belongs to the technical field of optical fiber detection. Multi-dimensional data acquisition including light source power fluctuation data, detector dark current data, optical fiber loss distribution data and environment temperature and humidity data is realized; preprocessing the collected multi-dimensional data, constructing a light source power drift model and a detector sensitivity drift model, and fitting model parameters; and calculating a corresponding error correction coefficient based on the light source power drift model and the detector sensitivity drift model, correcting the ratio of anti-Stokes light intensity to Stokes light intensity of Raman scattering in combination with a dynamic correction result of an optical fiber attenuation coefficient by environment temperature and humidity data, and outputting calibration temperature data. Therefore, on the basis of the Raman scattering technology, light source power fluctuation and detector sensitivity drift core errors are eliminated through a multi-dimensional error compensation model, and the temperature measurement precision is improved.

The utility model discloses a photodiode dark current testing device, comprising an LED lamp, a light shield, a dual-channel power supply, a desk type universal meter, a one-chip microcomputer control board and a multi-channel test board, the light shield is covered on the multi-channel test board, the multi-channel test board is provided with PD sockets having the same number as the channels of the multi-channel test board, and the PD sockets are connected with the desk type universal meter. The PD socket is composed of a 4P socket and Y-shaped sockets arranged side by side. After the scheme is adopted, the efficiency is greatly improved through multi-channel testing, and the vertical pins can be automatically tested through the design of the Y-shaped socket.

The invention relates to the technical field of micro-nano processing of semiconductor devices, in particular to an InAs / GaSb class-II superlattice mesa wet etching solution and a using method thereof, the etching solution is an aqueous solution comprising citric acid, phosphoric acid and hydrogen peroxide, the citric acid is citric acid monohydrate, the mass concentration of the phosphoric acid is 85%, and the mass concentration of the hydrogen peroxide is 30%. By optimizing the proportion of the components of the corrosive liquid and introducing an adjustable corrosion time sequence and a post-treatment technique, high repeatability and high uniformity of the corrosion process can be realized on the premise of keeping the intrinsic electrical properties of the material, the morphology quality of the mesa structure can be remarkably improved, and the smooth and low-damage mesa side wall and surface can be obtained. The method lays a reliable process foundation for preparing a high-performance InAs / GaSb class-II super-crystal-based infrared detector, is particularly beneficial to suppressing electric leakage of the side wall of a device, reduces dark current, and finally improves the quantum efficiency and imaging performance of the device.

The invention provides a mesa side wall passivation method for a class-II superlattice infrared detector and the infrared detector, and belongs to the field of semiconductor manufacturing. The problems of high interface state density and large dark current caused by a natural oxide layer rich in Sb2O5 formed by exposing the side wall of the aluminum antimonide or arsenic aluminum antimonide barrier layer to the atmosphere are solved; the method comprises the following steps of: cleaning and drying a second-class superlattice infrared detector chip subjected to mesa etching, and then loading the second-class superlattice infrared detector chip into a sample cavity of ALD (Atomic Layer Deposition) equipment; vacuumizing and heating; introducing high-purity hydrogen into a remote plasma source, starting the remote plasma source, selectively reducing the unstable natural oxide layer on the surface of the side wall of the barrier layer of the chip into volatile gas through hydrogen plasma, and pumping away the volatile gas through a vacuum system; after hydrogen plasma treatment is finished, a gas path is switched to an ALD precursor to form a passive film on the side wall of the barrier layer; cooling and taking the sheet; the invention is applied to the infrared detector.

A system for generating a dark current residual image is configurable to generate a weighted average image by: (i) determining a region-based weight value for each pixel of an input image based upon a light level of a region in which the pixel lies; and (ii) combining the input image with a previous image using the region-based weight values for each pixel of the input image. The system is also configurable to generate a dark current residual image based upon the weighted average image.

The embodiment of the present application discloses an image sensor and an electronic information device for improving full well capacity. The image sensor comprises: a photodiode formed in a semiconductor substrate; the photodiode comprises at least a first doped layer, a second doped layer and a columnar third doped region; the second doped layer wraps the side and bottom of the third doped region; the first doped layer wraps the side and bottom of the second doped layer; the first doped layer and the second doped layer form a first lateral PN junction; the second doped layer and the third doped region form a second lateral PN junction; wherein the first doped layer and the third doped region have the same conductivity type, and the conductivity type is opposite to that of the second doped layer. The embodiment of the present application replaces the central part of the photodiode with a columnar ion doped region (for example, a P-type layer), so that the image sensor with the epitaxial structure can effectively improve the full well capacity, effectively reduce the depletion potential of the center of the photodiode, avoid the occurrence of lag, and reduce the dark current.

The application discloses a kind of photovoltaic module dark current testing device, it is related to dark current detection device technical field, the detection device includes workbench, workbench is placed with cabinet, multiple drawers are slidably installed on cabinet, multiple current detection modules are evenly installed in drawer, workbench is installed with host computer, host computer is electrically connected with current detection module, temperature and humidity control assembly is provided on the cabinet, temperature and humidity control assembly adjusts the temperature and humidity inside cabinet, when drawer is completely pushed into cabinet, darkroom for accommodating photovoltaic module is formed, meet the lightless environment requirement of photovoltaic module dark current test, improve detection precision, host computer as the overall control unit of device forms the closed-loop control of "instruction issue-data acquisition-result feedback", display screen connected with host computer real-time display test state, real-time parameter and test result, replace artificial reading judgment, reduce error.

The invention discloses a long-wave infrared detector based on electric field intensity distribution regulation and control and a preparation method, and relates to the technical field of semiconductors, the long-wave infrared detector comprises a substrate, a bottom contact layer, a hole barrier layer, an absorption layer, an electron barrier layer and a top contact layer which are sequentially arranged from bottom to top; wherein the bottom contact layer and the hole barrier layer adopt an InAs / GaSb / AlSb / GaSb superlattice structure; the absorption layer, the electron barrier layer and the top contact adopt an InAs / GaSb superlattice structure; the doping concentration of the absorption layer is greater than the doping concentration of the hole barrier layer and the electron barrier layer. The doping concentration of the absorption layer is set to be greater than that of the barrier layer, so that the width of a depletion region of the absorption layer is reduced, the depletion region deviates towards the barrier layer, the probability of SRH recombination is reduced, G-R current can be effectively inhibited, and the overall dark current level is reduced.

A photonic random access memory employs series connected photosensors to define switching nodes driving optical modulators, the series connection operating to reduce the effect of photosensor dark current.

The invention provides an optical power detection circuit and optical power detection equipment, and belongs to the technical field of optical power detection, the circuit is used for carrying out optical power detection on a first photoelectric conversion module, and the circuit comprises an input buffer module which is used for carrying out zero-voltage bias on the first photoelectric conversion module and comprises a first input end, a second input end and an output end, the first input end is connected to the cathode end of the first photoelectric conversion module, the second input end is connected to the anode end of the first photoelectric conversion module, and the first input end is connected with the output end; the signal conversion module is used for amplifying the current signal output by the first photoelectric conversion module to realize optical power detection and comprises a first end and a second end, and the first end is connected with the second input end of the input buffer module and the anode end of the first photoelectric conversion module; the second end of the signal conversion module is connected to the first output end of the optical power detection circuit. According to the invention, the influence of dark current can be reduced, and the accuracy and stability of optical power detection are improved.

The application relates to a dual-wavelength silicon-based PIN photoelectric sensor with ultralow dark current and high responsivity, which comprises a silicon substrate, a central P + anode region, high resistance / intrinsic silicon absorption region, bottom N + cathode region, junction termination extension region JTE, guard ring GRL, surface passivation layer and electrode structure. Through accurate regulation of the junction edge electric field, the application effectively suppresses the leakage current and early breakdown phenomenon caused by the high edge electric field in the plane PIN structure, realizes sub-nanoampere dark current output, and simultaneously, through synergistic optimization of the intrinsic region thickness and the doping distribution, the sensor obtains higher light responsivity at two typical wavelengths of 660 nm and 940 nm, and meets the requirements of short-wave shallow absorption and long-wave deep absorption.

A LiGa-based 0.5 In 0.5 A self-driven X-ray detector based on Se2 crystal and its fabrication method. This detector employs an MSM device structure with c-plane LiGa... 0.5 In 0.5 Using Se2 wafers as semiconductor materials and metal materials as electrodes, self-driven X-ray detection can be achieved under zero bias voltage; the above-mentioned self-driven X-ray detector fabrication method includes the following steps: (1) fabricating LiGa 0.5 In 0.5 (1) Se2 crystal; (2) Directional processing of c-plane LiGa 0.5 In 0.5 Se2 wafer; (3) LiGa 0.5 In 0.5 The upper and lower surfaces of the Se2 wafer are polished and passivated; (4) in LiGa 0.5 In 0.5 Metal electrodes are deposited on the upper and lower surfaces of a Se2 wafer. This invention utilizes LiGa... 0.5 In 0.5 The bulk photovoltaic effect generated by the non-centrosymmetric structure of Se2 enabled the fabrication of a self-driven X-ray detector with a simple structure. Furthermore, due to the LiGa... 0.5 In 0.5 Se2 crystals have high resistivity, and the devices fabricated from them have low dark current, enabling highly sensitive X-ray detection.

The embodiment of the invention provides an optical detection circuit, an optical detection chip, an optical sensor and electronic equipment. The optical detection circuit comprises a signal processing unit, an optical detection unit and a voltage applying unit, the voltage applying unit is used for applying dark current detection voltage to the photodiode, so that the photodiode outputs a dark current detection signal to the signal processing unit based on the dark current detection voltage, and the signal processing unit generates a reference signal based on the dark current detection signal; the signal processing unit is used for receiving an induction signal generated by the photodiode in response to light irradiation after the voltage applying unit applies the optical detection voltage to the photodiode, and generating an optical detection signal according to the induction signal; and the optical detection unit is used for performing optical detection according to the optical detection signal and the reference signal. According to the optical detection circuit, the dark current of the photodiode can be detected in real time before optical detection, so that the accuracy of optical detection is improved.

Provided is a light receiving element capable of enhancing accuracy of measurement of color mixing components contained in output signals of light shielding pixels located around a light receiving pixel. A peripheral pixel region has a specific pixel group including a light receiving pixel and light shielding pixels surrounding the light receiving pixel. A first conductivity type region corresponding to the light receiving pixel and the light shielding pixels of the specific pixel group is made lower in concentration of a first conductivity type impurity than a first conductivity type region corresponding to an effective pixel located in an effective pixel region. Since the concentration of the first conductivity type impurity of the specific pixel group (the light receiving pixel and the light shielding pixels) is low, it is possible to weaken a pn junction strength and suppress dark current in the light receiving pixel and the light shielding pixels. It is therefore possible to reduce noise contained in the output signals of the light shielding pixels and enhance the accuracy of measurement of the color mixing components included in the output signals of the light shielding pixels.

To provide a digital input module that can switch voltage for contact detection with a simple configuration.SOLUTION: In a digital input module, when voltage for contact detection is applied to an external input terminal to which an external resistor is connected in parallel with an external device, contact detection is performed on the basis of dark current flowing in external wiring. A first power supply unit for applying the voltage for contact detection is configured to be capable of switching the voltage for contact detection on the basis of a setting signal.SELECTED DRAWING: Figure 1

The invention relates to the field of semiconductor material manufacturing, in particular to a molecular beam epitaxy heterogeneous base HgCdTe material and a preparation method thereof. In order to overcome the double defects of high dislocation density and out-of-control Se atom diffusion in the existing heterogeneous-base HgCdTe molecular beam epitaxy technology, a dislocation reaction is triggered by designing an HgSe superlattice structure, and an As-doped HgTe diffusion blocking layer is further constructed; finally, the molecular beam epitaxy heterogeneous base HgCdTe material can meet the core requirements of low dislocation density, zero Se diffusion and high stability of a high working temperature (greater than or equal to 150K) infrared detector. The problems that due to the fact that the dislocation density of a molecular beam epitaxy heterogeneous base HgCdTe is high, the dark current of a device is sharply increased, the blind pixel rate is increased, and Se diffusion of an epitaxial structure containing Se is out of control are solved.

The invention discloses a dark level automatic correction system, and relates to the technical field of image communication. The dark level automatic correction system comprises an accuracy calibration module, a uniformity calibration module and an accuracy evaluation module. Wherein the accuracy calibration module is used for dividing an image into a first area and a second area based on each area pixel of the image monitored by a camera in real time in a dark level calibration process, and carrying out image accuracy calibration according to the pixel number of the first area and each pixel value of the second area; the uniformity calibration module is used for performing pixel compensation calibration based on the uniformity evaluation result of the second region and the dark current data, and the pixel compensation calibration improves the image uniformity by dynamically adjusting a basic temperature compensation coefficient and a sensor bias voltage; and the accuracy evaluation module is used for carrying out calibration accuracy evaluation and feedback based on each region pixel of the camera image after the dark level calibration is finished.