36 results about "Light absorption coefficient" patented technology

The invention belongs to the technical field of deep learning, particularly relates to a two-stage blind image defogging method based on prior guide diffusion, and aims to solve the problem of distortion of a traditional decontamination method in a complex scene. Comprising the steps that a double-stage blind image defogging model is constructed, and the double-stage blind image defogging model comprises a first stage and a second stage; wherein in the first stage, physical modeling is carried out based on an improved atmospheric scattering model, the improved atmospheric scattering model is an enhanced atmospheric scattering model in which a light absorption coefficient is introduced, and a transmission image, a fogless reference image and atmospheric light parameters are output through the first stage; in the second stage, generation optimization is carried out based on a diffusion model, the transmission image, the fog-free reference image and the atmospheric light parameters output in the first stage are used as physical priori to be fused into the generation process of the diffusion model, and image defogging is carried out. In the second stage, self-adaptive difference fusion convolution is set, a fog domain multi-source fusion attention mechanism is set, and a pixel level and wavelet domain double-effect color correction strategy is adopted.

The invention relates to the technical field of semiconductor photoelectric devices, and discloses a GeSe / Si heterojunction photoelectric device and a preparation method thereof, the GeSe / Si heterojunction photoelectric device comprises a bottom electrode, an n-type silicon substrate, a GeSe layer and a top electrode; wherein the n-type silicon substrate and the GeSe layer form a Van der Waals heterojunction, the whole GeSe / Si heterojunction photoelectric device is of a sandwich structure, the bottom electrode is in contact connection with the n-type silicon substrate, and the top electrode is in contact connection with the GeSe layer. The GeSe / Si Van der Waals heterojunction-based high-performance photoelectric device with a sandwich structure and an II-type energy band structure is designed and prepared, due to the light transmission of the Au / ITO top electrode, GeSe with a high light absorption coefficient is used as a light absorption layer, a large number of photon-generated carriers can be generated, and the photoelectric device can be applied to the field of photoelectric devices. A built-in electric field and an II-type energy band structure of the GeSe / Si heterojunction can quickly separate photon-generated carriers to form light current, so that high responsivity of 29.8 A / W, high quantum efficiency of 6959.7% and quick light response time of 8.5 / 23.7 us are realized.

The application discloses a kind of bromine iodine lead cesium perovskite solar cells of doping magnesium bromide prepared in low humidity environment and preparation method thereof, belong to perovskite photovoltaic technical field, including ITO transparent conductive glass and sequentially coated on ITO transparent conductive glass dense layer TiO2, SnO2 layer, bromine iodine lead cesium perovskite light-absorbing layer of doping magnesium bromide, 2,2',7,7'-tetra [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene hole transport layer of doping lithium salt, silver electrode, and its preparation method is disclosed, the application is by doping into bromine iodine lead cesium perovskite precursor doping different molar magnesium bromide to optimize the energy level matching between perovskite and electron transport layer and hole transport layer, effectively reduce the recombination probability of carrier and improve the mobility of carrier, improve the crystal quality of perovskite thin film, to realize the light absorption coefficient of optimization light-absorbing layer, finally realize the improvement of bromine iodine lead cesium inorganic perovskite solar cell photoelectric conversion efficiency.

The application provides a glass material, wherein a cation component contains, in terms of mole percentage, Si 4+ : 4-16%; B 3+ : 45-70%; La 3+ : 3-18%; Ca 2+ : 2-20%; and an anion component contains F ‑ : 1-15%; O 2‑ : 85-99%. Through reasonable component design, the glass material has high refractive index and low light absorption coefficient, and meets the application in the fields of image transmission optical fibers and the like.

The invention relates to an opto-acoustic-ultrasonic multi-mode bone metabolism and senescence noninvasive detection method and device, and the method comprises the following steps: respectively collecting an ultrasonic signal and a multi-wavelength opto-acoustic signal in a detection period; calculating the ultrasonic sound velocity and the broadband ultrasonic attenuation coefficient of the to-be-detected bone based on the ultrasonic signal, comparing the ultrasonic sound velocity and the broadband ultrasonic attenuation coefficient with the data of the healthy bone, and preliminarily judging the health degree of bone metabolism; based on the ultrasonic sound velocity and the broadband ultrasonic attenuation coefficient of the to-be-detected bone, performing ultrasonic attenuation compensation on a bone tissue part in the photoacoustic signal; fitting the opto-acoustic signal subjected to ultrasonic attenuation compensation corresponding to each wavelength into a transmission equation of a macroscopic homogeneous medium, calculating to obtain a relative light absorption coefficient of each wavelength, and mapping the relative light absorption coefficient and the corresponding wavelength to obtain a relative light absorption spectrum of the to-be-detected skeleton; and performing linear fitting on the relative light absorption spectrum and the main component spectrum in the skeleton, decoupling related photoacoustic parameters of the chemical component content, and further judging the skeleton metabolism and aging degree. Compared with the prior art, the method has the advantages of being low in detection complexity, non-invasive, non-radiative, capable of comprehensively obtaining physical microstructures and biochemical information related to bone metabolism and aging and the like.

The invention discloses a multi-dimensional element and physical constraint fused atmospheric black carbon source analysis method and system, and the method comprises the steps: obtaining a ratio of BC total mass concentration to a primary light absorption coefficient, and calculating a primary BC light absorption coefficient according to the BC total mass concentration and the ratio; carrying out pretreatment on the primary BC light absorption coefficient; sending the preprocessed primary BC light absorption coefficient and the obtained environmental data into a pre-trained neural network model to obtain light absorption coefficients, BC total mass concentration and BC mass concentration discharged by each discharge source under different wavebands output by the neural network model; when the neural network model is constructed, an activation function and a loss function are defined, and training is completed. The method is based on the atmospheric environment data, combines the physical process of atmospheric BC quality and light absorption coefficient change, overcomes the defect that a traditional neural network model lacks physical significance, and is suitable for BC source analysis tasks in different regions and different atmospheric environments.

This invention relates to the field of graphene quantum dot film technology, and discloses a graphene quantum dot film, its preparation method, and its applications. The film is composed of the following components: modified graphene quantum dots, inorganic nanoparticles, a polymer matrix, a dispersant, a crosslinking agent, and additives. Through the optimized integration of raw material design and preparation process, the graphene quantum dot film of this invention achieves a synergistic improvement in both microstructure and macroscopic performance. From a macroscopic perspective, the film's transmittance reaches a maximum of 91.3% at 550 nm, and its light absorption coefficient reaches 4.0 × 10⁻⁶. 4 cm ‑1 The material exhibits a maximum tensile strength of 48.6 MPa and an elongation at break of 4.5%, and maintains a high performance retention rate even after humid heat and ultraviolet light aging. These superior properties are attributed to the synergistic effect of modified graphene quantum dots, modified inorganic nanoparticles, and optimized polymer matrices, as well as the regulation of processes such as segmented ultrasonication-intermittent stirring and gradient curing.

The invention relates to a sparse regularization photoacoustic imaging de-mixing method and system based on end member automatic extraction. The method comprises the following steps: collecting a multi-wavelength photoacoustic signal and reconstructing a photoacoustic image; based on the photoacoustic image, searching a pixel which enables a convex hull to expand continuously through orthogonal projection, extracting an end member in the photoacoustic image, and performing smoothing processing to obtain an end member curve; and taking the extracted end member curve as priori knowledge, introducing sparse regularization constraint into a target function of photoacoustic imaging unmixing, and solving abundance distribution of each component in the biological tissue by minimizing the target function to obtain an unmixing result. Compared with the prior art, the method has the advantages that the light absorption coefficient of each substance does not need to be obtained as priori knowledge, and the over-fitting resistance is high.

An object of the present application is to provide an organic EL element having a capping layer composed of a material having the following properties: (1) high light absorption coefficient, (2) high refractive index, (3) good stability of thin film, (4) excellent durability, (5) excellent light resistance, and (6) no absorption in the respective wavelength regions of blue, green, and red. Since the arylamine-based material having a specific structure of the present application is excellent in stability of thin film and durability, an amine compound having a specific benzoxazole ring structure and a high refractive index is selected as a material constituting the capping layer, and an organic EL element using the material having a high absorbance at a wavelength of 400 nm to 410 nm in an absorption spectrum at a concentration of 10 ‑5 mol / L shows good element characteristics.

The invention discloses a remote sensing estimation method and a remote sensing estimation device for the primary productivity of marine phytoplankton in size fraction, and the method comprises the steps: building an estimation function of the photosynthetic quantum yield of the phytoplankton in the corresponding size fraction based on the relation between the light intensity and the photosynthetic quantum yield of the phytoplankton in the single size fraction; calculating the net primary productivity of the phytoplankton of the corresponding size fraction based on the photosynthetic quantum yield and the average light absorption coefficient of the phytoplankton of the single size fraction under the scale of the light intensity duration and the ocean depth measurement range; and adding the net primary productivity of the phytoplankton in the plurality of size fractions, and calculating to obtain the total primary productivity of the phytoplankton. By adopting the technical scheme, in a framework of light absorption and conversion of the phytoplankton, the light absorption coefficient of the phytoplankton with different size fractions and the size fraction difference of the photosynthetic quantum yield are considered at the same time, an effective scheme for quantitative expression estimation of the phytoplankton is established, the estimation error of the primary productivity caused by neglecting the size fraction difference can be effectively reduced, and the estimation accuracy of the primary productivity is improved. And the estimation accuracy is improved.

The invention relates to the technical field of security check, and discloses an integrated system based on radioactive substance detection and X-ray radiation imaging. The system comprises an initial modeling module, a detection planning module, a signal acquisition module, a data fusion module, a collaborative analysis module and a comprehensive judgment module. The initial modeling module establishes a synchronous initial space model, the detection planning module generates a key detection subspace according to historical attenuation probability distribution of radioactive substances, the signal acquisition module captures radioactive signals and extracts an X-ray density image, and the data fusion module aligns two types of data time sequences and peels off independent signal streams. The collaborative analysis module identifies suspected core points and calculates X-ray absorption coefficient abnormal fluctuation, and the comprehensive judgment module obtains a judgment result. The system can improve the radioactive signal capturing efficiency, avoid signal interference and enhance the accuracy of radioactive substance judgment, and is suitable for the field of radioactive substance detection.

The application discloses a three-dimensional trench silicon electrode detector and a preparation method thereof. The detector is composed of a plurality of detection units. The detection unit comprises a silicon dioxide protective layer, an outer electrode arranged on the silicon dioxide protective layer, a silicon base and a center electrode arranged on the silicon dioxide protective layer and in the outer electrode. The silicon base comprises a base part and a nested part. The nested part is embedded in the outer electrode and located on the base part. The center electrode and the nested part are filled with an insulator between the center electrode and the outer electrode and between the nested part and the outer electrode. An electrode contact aluminum layer is arranged on the top of the outer electrode, the center electrode and the insulator. An electrode contact port is arranged on the electrode contact aluminum layer of the outer electrode and the center electrode. The application solves the problem that the existing detector has a small light absorption coefficient, a narrow absorption spectrum and cannot fully absorb and utilize solar energy.

The present application provides a silicon substrate, comprising a first surface and a second surface which are opposite to each other. A plurality of recesses are formed in the first surface. The thickness of the silicon substrate is h1, and the depth of the recesses is h2, wherein the difference Δh between h1 and h2 satisfies h1>Δh≥1 / A(λ=300 nm), wherein A(λ=300 nm) is an optical absorption coefficient of the silicon substrate at a wavelength λ=300 nm, with a unit of cm-1. The present application further provides a solar cell and photovoltaic module comprising the silicon substrate. By forming the recesses and establishing a relationship among the depth of the recesses, the thickness of the silicon substrate, and the optical absorption coefficient of the silicon substrate at a corresponding wavelength, absorption of oblique incident light by the recesses is enhanced, and the requirements for specific wavelength response are met.

A puncture path planning method and planning system. The puncture path planning method comprises: constructing a three-dimensional model from a medical image; defining organs and tissue as units having not completely identical light absorption degrees, and assigning light absorption coefficients to the units on the basis of whether a biopsy needle is allowed to pass through and the risk level of puncture; and setting a light source in a puncture target region, obtaining grayscale information on the skin surface by means of analysis of light absorption degrees along different paths, and using the grayscale information to feed back a recommendation degree for each puncture starting point. By converting the selection of a puncture path into the problem of finding an optimal puncture starting point, in combination with a light propagation principle, the novel puncture path planning method and planning system can intuitively display location information of a preferred puncture starting point and are more comprehensive and reliable.

The present disclosure provides a photoelectric conversion element including a first electrode 3, a second electrode 7, a photoelectric conversion layer 5 between the first electrode 3 and the second electrode 7, and a reflection layer 6 between one of the first electrode 3 and the second electrode 7 and the photoelectric conversion layer 5. The wavelength at which the reflectance of the reflection layer 6 is maximum in the visible region is within the range of wavelengths in which the optical absorption coefficient of the photoelectric conversion layer 5 is ⅕ or more of the maximum optical absorption coefficient in the visible region.

The invention relates to a material photoacoustic spectrum measurement method and device. The method comprises the following specific steps: S1, respectively collecting photoacoustic signal data of a standard solution and a to-be-measured solution under different wavelengths; s2, processing the photoacoustic signal data through a reconstruction algorithm to generate an image, and obtaining photoacoustic signal intensity values I of the standard solution and the to-be-detected solution in each region and each scanned wavelength by using the image; and S3, performing double calibration on the obtained photoacoustic signal intensity values I of the standard solution and the solution to be detected to obtain the relative light absorption coefficient of the solution to be detected. The photoacoustic spectrum measuring method based on the photoacoustic imaging system is rapid, convenient and accurate, system operation is simplified, optical differences of biological tissues and instability of a laser system can be effectively coped with, and therefore the consistency of the photoacoustic spectrum and a real optical absorption spectrum is improved, and the measuring accuracy of the photoacoustic spectrum is improved. Therefore, accurate analysis of molecular components in biological tissues is supported.

A kind of high photosensitivity slurry of pure copper photocuring 3D printing and preparation method thereof.The high photosensitivity slurry of pure copper photocuring 3D printing composition includes pure copper powder, active diluent, photoinitiator and auxiliary agent.The active diluent is acrylate monomer, and the photoinitiator includes two groups, one group is cleavage type alpha-amino ketone and its derivative, and the other group is thioxanthone and its derivative group.The thioxanthone photoinitiator has higher molar extinction coefficient in the ultraviolet light around 360nm-405nm wavelength, can compete with copper powder for ultraviolet light to avoid the high light absorption coefficient of copper powder to reduce the light initiation efficiency.At the same time, after thioxanthone absorbs ultraviolet light, energy transfer occurs with alpha-amino ketone, so that alpha-amino ketone photoinitiator jumps to excited triplet state, indirectly realizes slurry photopolymerization, greatly improves the light initiation efficiency, improves the photosensitivity of slurry, and solves the problem of high ultraviolet absorbance of copper powder.

The polarizing plate of the present application is obtained by laminating a polarizer, a first protective film disposed on one side thereof, a second protective film disposed on the other side, and a release film disposed on the side of the first protective film opposite to the polarizer. The light absorption coefficient A2 of the second protective film for light having a wavelength of 9.4 μm is 1.0 x 10 2 ~ 4.5 x 10 2 / μm. In a cross section of the polarizing plate along the lamination direction, the inclination angle φ of a straight line connecting an end point P1 of the release film on the side opposite to the first protective film in the cut end surface and an end point P2 of the second protective film on the side of the polarizer with respect to the lamination direction is 0.5 ~ 10°.

The present disclosure discloses a puncture path planning method and a planning system, that leverages principles from optics and computer rendering. The method rapidly calculates optimal puncture paths to serve as a reference for medical personnel, serving as an auxiliary means for information acquisition in clinical practice. The method includes: constructing a three-dimensional model based on medical images; defining organs and tissues as units with different light absorption degrees; assigning light absorption coefficients to each unit according to whether the biopsy needle is allowed to pass and the puncture risk level; placing a light source on a puncture target region; and obtaining grayscale information on the skin surface by analyzing light absorption along different paths, wherein the grayscale information is used to provide feedback on the recommendation level of each puncture starting point.

The photo-acoustic conversion based sound emitter device has a sound output surface for transmitting sound wave vibrations to a medium outside the device. An optical waveguide, is used to transmit light through an optical path within the device. First and second photo-acoustic conversion volumes, at different distances from the sound output surface, are used for transmitting sound generated in the first and second volume to the medium via the sound output surface, the optical path extending directly or indirectly successively through the first and second photo-acoustic conversion volume. The device comprises an intermediate volume separating the first and second photo-acoustic conversion volumes along the optical path, the intermediate volume having a lower light absorption coefficient than the first and second photo-acoustic conversion volumes; and / or the first and second photo-acoustic conversion volume have a different cross-section area size and / or shape with virtual planes perpendicular to the optical path; and / or the first and second photo-acoustic conversion volumes have different optical absorption coefficients, or a different optical wavelength dependence of these optical absorption coefficients.

The invention discloses a spinel ferrite photocatalytic material screening method based on synergic regulation and control of reversal degrees and A-site cations. The method comprises the following steps: firstly, constructing AFe2O4 type spinel ferrite structure models of different A-site cations and [AxFe1-x] [Fe2-yAy] O4 type spinel ferrite structure models of different reversal degrees; then, the formation energy and phonon spectrum of each model are calculated by adopting a first principle, and unstable models are removed; the electron energy band structure, the carrier effective mass and the light absorption coefficient of the reserved thermodynamically and dynamically stable model are further calculated with high precision, and the model meeting the requirements of the ideal photocatalytic material electron structure and the light absorption coefficient is reserved; and then calculating the carrier mobility based on a deformation potential theory, calculating the service life of the optical excitation carrier by using a non-adiabatic molecular dynamics method, and preferably selecting a model with high mobility and long service life of the carrier as a potential photocatalytic material.

The invention relates to the technical field of medical imaging, in particular to an oxygen saturation quantitative imaging device and method for an endoscope. The shooting part is configured to collect reflected light of the target area under illumination of the light source and output a collected color image and an exposure control parameter corresponding to the color image; the image processing part comprises a spectrum reconstruction module which is used for carrying out image de-gain processing on the color image and reconstructing a single-band image signal with a set wavelength; the light intensity estimation module is used for respectively calculating light intensity data of the light sources; and the quantitative calculation module is used for calculating a light absorption coefficient based on the light intensity data, calculating oxyhemoglobin concentration, deoxidized hemoglobin concentration and an oxygen saturation value based on the light absorption coefficient, and generating an oxygen saturation distribution image. The oxygen saturation image generated by the method has rich anatomical structure information and accurate physiological parameter information, and a tissue hypoxia region can be visually displayed.

The invention discloses a medium-band-gap acceptor material containing a perfluoroindandione end group, a preparation method of the medium-band-gap acceptor material and application of the medium-band-gap acceptor material to a photovoltaic device. The structural formula of the medium-band-gap acceptor material is shown as a formula I, wherein A is a perfluoroindandione end group; d is an electron donor skeleton; the application is a laminated organic photovoltaic device and an indoor organic photovoltaic device prepared from the medium-band-gap acceptor material. According to the perfluoro end group acceptor provided by the invention, the band gap is effectively widened to 1.55-2.0 eV, the perfluoro end group acceptor has a high light absorption coefficient, and the perfluoro end group acceptor has the advantages of being good in solubility, easy to process into a film and the like. And the prepared organic photovoltaic device has high open-circuit voltage, short-circuit current and fill factor and excellent photoelectric conversion efficiency.

The application discloses a kind of based on Monte Carlo model's light absorption coefficient accurate measurement method, system, equipment and medium, wherein the method includes constructing multimodal microscopic imaging system;Obtain the experimental photoacoustic data of multimodal microscopic imaging system, and the actual absorption light energy density is obtained by solving photoacoustic wave equation using finite element method;Given a hypothetical absorption coefficient, simulated calculation is carried out using Monte Carlo model to obtain simulated absorption light energy density;The deviation between actual absorption light energy density and simulated absorption light energy density is minimized by iterative least square method optimization, and the absolute light absorption coefficient is obtained. A multimodal microscopic imaging system is constructed by a fluorescence imaging microscope and a photoacoustic microscope, which combines the accuracy of FEM in solving photoacoustic wave equation and the rigorous modeling of MC in photon migration in biological tissues, and realizes the comprehensive quantitative reconstruction of optical absorption characteristics.

The present application relates to a kind of low-energy consumption flexible organic synapse transistor of photoelectric synergistic response and its preparation method and use, belong to the field of photoelectric thin film device.The organic synapse transistor is realized photoelectric synergistic response by constructing high light absorption coefficient and high carrier mobility organic semiconductor layer, and the interface passivation dielectric layer / polyelectrolyte dielectric layer composite film with high light transmittance and low gate voltage control ability realizes low power consumption synapse function;The device can work at-5 millivolt, and its single synapse pulse event energy consumption is as low as 8.5 fJ.This application can efficiently simulate the plasticity function of biological synapse by the synergistic effect of photoelectric pulse signal stimulation and the flexible modulation of synaptic weight.Compared with traditional technology, the flexible organic synapse transistor of the present application is simple in structure, rich in control means and low in working energy consumption, which can promote the development of low-cost bionic photoelectric synapse, brain-like neural morphological device, intelligent chip and sensing-computing terminal.

[Problem] To provide a light detection device and a distance measurement device in which it is possible to realize a multiplication region and a photoelectric conversion unit having suitable characteristics. [Solution] A light detection device according to the present disclosure comprises: a substrate (1) which includes, in a region of a single pixel, a first semiconductor layer (11), a second semiconductor layer (12), and a first multiplication region (R2), and in which the first semiconductor layer (11) has sensitivity with respect to infrared light in a first wavelength range, the second semiconductor layer (12) has sensitivity with respect to infrared light in a second wavelength range different from the first wavelength range, and has an absorption coefficient, with respect to the infrared light in the second wavelength range, greater than that of the first semiconductor, and the first multiplication region (R2) multiplies a carrier from the first semiconductor layer (11); and a first electrode (CA2) which is electrically connected to the first multiplication region (R2).

The invention discloses a quantitative photoacoustic tomography method and system based on PnP-ADMM, and relates to the field of medical imaging, and the method comprises the steps: building a forward imaging physical model; determining a pre-trained deep denoising network; the deep denoising network is an improved DRUNet; reading a sound pressure signal measurement value; constructing a nonlinear least square optimization function; on the basis of a forward imaging physical model, a pre-trained deep denoising network and the sound pressure signal measurement value, PnP-ADMM is adopted to iteratively solve a nonlinear least square optimization function, and a light absorption coefficient distribution diagram of the biological tissue to be measured is obtained; and the PnP-ADMM adopts an L-BFGS algorithm to iteratively solve the light absorption coefficient distribution, and takes the pre-trained deep denoising network as a prior noise reduction module in the PnP to replace a near-end operator in the ADMM to iteratively solve the auxiliary variable. According to the method, high-quality and high-efficiency reconstruction of the biological tissue light absorption coefficient distribution diagram is realized.

The present application relates to the technical field of food detection, in particular to a method for detecting the protein content in soy milk powder, comprising: obtaining the original near-infrared spectrum data of the soy milk powder sample to be detected and constructing a protein characteristic vector; calling a preset protein optical constant database storing the light absorption coefficient and refractive index under different protein concentrations, matching and then backstepping the average light path and extinction coefficient of the protein molecules to obtain light path extinction data; based on the data, establishing an absorption kinetics model to simulate the propagation process of light in the suspension and obtain the light intensity decay state, and after time integration, obtaining the cumulative absorbance proportional to the number of protein molecules; combining the dry weight of the sample to calculate the protein content per unit mass, and after environmental temperature compensation to correct the spectral drift, outputting the standardized detection result. The method can improve the accuracy and stability of the detection of the protein content in soy milk powder.

The application discloses a kind of seawater turbidity and CDOM content in-situ online measuring device and method, according to the characteristic wavelength of the characteristic difference of seawater turbidity and CDOM to light absorption or fluorescence generation, with multiple ultraviolet light tubes and infrared light tubes comprising multiple light source arrays as the driving light source of measurement system, the light emitted by light source enters the measured water sample containing CDOM after a series of optical lens combination, light is partially absorbed while exciting the characteristic wavelength related to the fluorescence of CDOM component, select narrow-band coated lens with wavelength selective transmittance to cooperate with photon counting detector to realize the detection of excited fluorescence, select wide-band coated lens to cooperate with high-sensitivity photoelectric detector to realize the detection of infrared light absorption coefficient and ultraviolet light absorption coefficient, the output signal of each detector is analyzed and processed by signal processing circuit system circuit board, obtain seawater turbidity and CDOM content information, and use turbidity information for online compensation of CDOM measurement.

This invention provides a group III nitride crystal, a group III nitride substrate, and a method for manufacturing the group III nitride crystal. It provides a group III nitride crystal with excellent conductivity and low light absorption coefficient. The group III nitride crystal is doped with an N-type dopant and hydrogen, with the N-type dopant concentration being 1 × 10⁻⁶. 20 cm ‑3 The concentration of hydrogen is 1 × 10⁴. 19 cm ‑3 above.