78 results about "Free carrier" patented technology

The invention discloses a monometallic waveguide GaN-based terahertz quantum cascade laser, which is characterized in that the bottommost layer of the structure is a substrate, an n-type highly-doped n + + layer, a QCL active region and an n-type doped layer are sequentially arranged on the substrate, a cathode electrode layer is arranged on the n-type highly-doped n + + layer, an anode electrode layer is arranged on the n-type doped layer, and an anode electrode layer is arranged on the anode electrode layer. Wherein the substrate is a GaN substrate, an AlN substrate or a SiC substrate. The invention also discloses a preparation method. On the basis of systematic research on refractive index related parameters of GaN under THz frequency, absorption of single-metal waveguide structure parameters on QCL light field limiting factors and free carriers is analyzed, and QCL with high light field limiting factors and low loss of different substrates is designed. Besides, according to the designed active region structure, the gain can reach 88 / cm at 10K and can reach 34 / cm at 280K, the corresponding wavelength is 6.6 THz, and the frequency which cannot be achieved by a traditional GaAs system is achieved.

The invention discloses a wide-temperature-range perovskite optical storage material and a preparation method and application thereof, the chemical general formula of the wide-temperature-range perovskite optical storage material is CsCdCl3: xSb < 3 + >, yMn < + >, Mn < + > is Zr < 4 + >, Sn < 2 + >, Hf < 4 + > or Gd < 3 + >, x is more than 0 and less than 0.06, and y is more than 0 and less than 0.02. The perovskite crystal can generate free carriers under excitation of X-rays or 365-nanometer ultraviolet light, the carriers can be stored in a crystal defect trap, and the storage temperature of the carriers covers an ultra-wide temperature range from 100 K to 350 K, so that wide-temperature-range X-ray imaging, information storage and anti-counterfeiting application can be realized.

The utility model relates to the technical field of MOS semiconductors, and discloses a super junction MOS semiconductor device, including a MOS semiconductor composed of a plurality of MOS cells, wherein the MOS cell includes a drain, a semiconductor epitaxial layer, a metal source and a gate; wherein the semiconductor epitaxial layer includes a substrate layer, a diffusion layer, a P well layer, a highly doped N well layer and a highly doped P body region; the P well layer includes a highly doped P well layer 1, a highly doped P well layer 2, a low doped P well layer 1 and a low doped P well layer 2; when the voltage of the gate is zero, free carriers exist in the charge channel formed in the low doped P well layer 2 and form a conductive path. The P+ region (high doped P well layer 18 body region) of the super junction structure is used to block the flow of charges between adjacent cells, thereby avoiding the problem that when the conduction states of the cells are different due to process differences, the better cells are subjected to a larger current, thereby causing premature damage, and then damaging the entire device.

The invention discloses a preparation method of a gallium oxide semi-insulating substrate and the gallium oxide semi-insulating substrate, which comprises the following steps: performing proton irradiation treatment on a gallium oxide single-crystal substrate to introduce lattice defects into the gallium oxide single-crystal substrate, and performing annealing treatment on the gallium oxide single-crystal substrate into which the lattice defects are introduced to obtain the gallium oxide semi-insulating substrate. According to the technical scheme, lattice defects are introduced into the gallium oxide single crystal substrate by adopting a proton irradiation process to form a deep energy level trap to effectively capture free carriers, so that the carrier concentration of the material is remarkably reduced, and the resistivity of the material is increased, thereby realizing stable conversion from a conductive state to a semi-insulating state; therefore, the conditions of poor doping uniformity, insufficient thermal stability and local resistivity fluctuation existing in a traditional element doping method are overcome, meanwhile, the defects of lattice mismatch, insufficient thermal conductivity and the like caused by a heterogeneous substrate are avoided, and the electrical property uniformity and the material structure integrity of the gallium oxide substrate are effectively improved. The method has the advantages of non-contact, low cost, easy regulation and control and the like.

The invention relates to the technical field of infrared optical materials, and particularly discloses an N-type chromium-doped high-resistance infrared silicon single crystal and a preparation method thereof. The N-type chromium-doped high-resistance infrared silicon single crystal is singly doped, the doping concentration of chromium oxide is 40-160ppm, and in the preparation process, specific constant-temperature heat treatment is carried out in a cooling stage. The concentration of free carriers in the silicon single crystal is remarkably reduced by singly doping chromium oxide and utilizing the deep energy level compensation effect of chromium element, the conduction type of the single crystal is N type, the resistivity is stably increased to above 1120ohm.cm, the average infrared transmittance of the wave band of 2-6 microns is greater than 53%, the stress birefringence is less than 3nm / cm, the process window is wide, and the operation is simple and convenient. The method is particularly suitable for preparing the silicon single crystal of a large-size and high-performance infrared optical system.

The invention relates to a photovoltaic module processing method and photovoltaic module processing equipment. The photovoltaic module processing method comprises the following steps that a solar cell and a welding strip are provided, the solar cell comprises a cell piece, a positive electrode grid line and a negative electrode grid line, and the positive electrode grid line and the negative electrode grid line are located on the surface of the cell piece. And applying a reverse voltage to the solar cell through the positive grid line and the negative grid line. And welding the welding strip on the solar cell by adopting laser welding. In the processing method of the photovoltaic module, reverse voltage is applied to the solar cell and laser welding is adopted, so that charge carriers in the solar cell can be excited to generate several amperes of current, and free carriers are forced to pass through a grid line to be in contact with a cell piece, so that the contact resistance between the grid line and the cell piece can be reduced; ohmic resistance between the grid line and the battery piece is improved, and the photoelectric conversion efficiency of the photovoltaic module is further improved.

The invention provides a broadband high-reflection metal ceramic layered composite material and a preparation method and application thereof.A compact ceramic matrix BaLa2Ti3-xHfxO10 is prepared through a solid-phase reaction, x is larger than 0 and smaller than 0.9, Ti < 4 + > is equivalently replaced with Hf < 4 + > to regulate oxygen vacancies and defect energy levels in crystals, intrinsic / impurity absorption is reduced, and the visible near-infrared reflection performance is improved. And then a metal layer is constructed on the ceramic substrate through magnetron sputtering, and the layered composite material is formed. The average reflectivity of the composite material is 77% at the wave band of 0.5-2.5 microns, and the average reflectivity of the composite material is 70% at the wave band of 2.5-20 microns; and the metal layer provides free carrier retroreflection and crack bridging effects, so that the thermal shock resistance and the cracking resistance are remarkably improved, and light-heat-force collaborative optimization is realized. According to the invention, ultra-wideband high reflection and high-temperature mechanical reliability are both considered, and the material is suitable for scenes such as light path reflectors, laser protection, radiation reflection heat insulation protection and infrared stealth.

This application relates to the field of coated glass technology, providing a high-temperature resistant transparent conductive oxide coated glass, its preparation method, and its application. The transparent conductive oxide coated glass includes a glass substrate, a shielding layer, an antireflective layer, a first conductive layer, and a second conductive layer stacked sequentially. The first and second conductive layers are fluorine-doped tin dioxide layers, with a crystallinity of ≥50% and a grain size of ≥50 nm. The transparent conductive oxide coated glass provided by this application has an antireflective layer that prevents sodium and potassium ions from the glass substrate from entering the conductive layer, improving the conductivity stability of the conductive layer at high temperatures. The antireflective layer improves the transmittance of the transparent conductive oxide coated glass. The first and second conductive layers ensure that the mean free path of free carriers at high temperatures is much smaller than the grain size, reducing the influence of grain boundary scattering on Hall mobility and further improving the photoelectric performance of the conductive layer at high temperatures.

The invention discloses an erbium-doped zinc selenide composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving zinc nitrate hexahydrate and erbium nitrate hexahydrate in deionized water, wherein the molar ratio of erbium ions in the zinc nitrate hexahydrate is 0.02-0.08; adding sodium selenite and sodium hydroxide; adding a reducing agent hydrazine hydrate; after hydrothermal reaction for h, washing and drying to obtain the erbium-doped zinc selenide composite material. The material is of a cubic phase ZnSe structure, erbium is uniformly doped in crystal lattices, and the material is in a nearly spherical particle shape. Rich 4f electronic defect states are introduced into a ZnSe band gap through erbium doping, charge transfer (chemical enhancement) is remarkably promoted, the free carrier concentration is improved to excite localized surface plasma resonance (electromagnetic enhancement), and the synergistic effect of two enhancement mechanisms is achieved. The detection limit of the SERS substrate to methylene blue is as low as 3.24 * 10 <-8 > mol / L, the enhancement factor is as high as 1.73 * 10 < 4 >, and a new way is provided for environmental pollutant monitoring.

An optical nonlinearity measurement method according to the present disclosure utilizes photon pair generation through a spontaneous four-wave mixing process, to observe photon pairs using an optical waveguide loaded with a two-dimensional material. Compared with the Z-scan method, the influence of free carriers on nonlinear refractive indexes is only indirect. With a parameter being the length of the attached two-dimensional material in the optical waveguide direction, a theoretical value of the coincidence rate of the photon pairs based on the coupled wave equation is fitted to a measured value of the coincidence rate of the photon pairs. For the coincidence rate of the photon pairs, the theoretical value based on the coupled wave equation is fitted to the measured value in a state reflecting the structure of the optical waveguide loaded with the two-dimensional material, and nonlinear coefficients γ1 and γ2 at that time are obtained.

The present invention discloses a chip-integrated electro-optical signal conversion method based on a two-dimensional layered material film. The two-dimensional layered material film is applied to the surface of a chip-integrated waveguide, and a modulation voltage is applied to the two-dimensional layered material film. By varying the free carrier concentration and adjusting the refractive index of the chip-integrated waveguide, the electro-optical phase modulation of the transmitted light field is achieved, effectively converting electrical signals into optical signals. Furthermore, the transmitted light field causes a change in the free carrier concentration of the two-dimensional layered material film, and by detecting the conductivity, efficient conversion of optical signals into electrical signals is achieved. The present invention avoids waveguide breakdown caused by excessively high modulation voltages through the thin film structure, and boasts a simple preparation process and high conversion speed. This method can lay a solid technical foundation for chip-integrated optoelectronic systems, particularly microwave photonic systems.

The invention discloses an infrared reflection pigment and a preparation method thereof, and the preparation method comprises the following steps: weighing a Y source, a Ce source, an Al source and a Mn source according to a chemical general formula of a product, x is less than or equal to 0.02, 0lt; y < = 0.2; stirring and mixing a Y source, a Ce source, an Al source, a Mn source, a complexing agent and a solvent to obtain a mixed solution, and adding the mixed solution into the precipitant solution for reaction to obtain an insoluble substance; and mixing the insoluble substance with a mineralizing agent, and calcining to obtain the infrared reflection pigment. According to the invention, based on the basic configuration of YAlO3, Ce with variable valence and an ion radius similar to that of Y is introduced to reduce chemical defects on the surface of a material, and Mn is introduced to bring certain lattice defects, so that the concentration of free carriers in crystals is reduced, and the near-infrared reflectivity of the pigment is improved.

This device comprises: a reception unit that, prior to transmission of a transmission signal to a wireless communication device, receives a first signal that is a modulation-free carrier wave from the wireless communication device; and a control unit that controls transmission of the transmission signal to the wireless communication device on the basis of the first signal.

A method of manufacturing a Kerr effect electro-optical modulator, comprising the steps of: a) using a substrate (1); b) forming a waveguide (2) on the substrate (1) so as to guide propagation of an electromagnetic wave, the waveguide (2) comprising: - a core (20), comprising a pn-type junction or a pin-type structure; - an optical cladding (21), surrounding the core (20); the core (20) and the optical cladding (21) having an interface (I); c) irradiating the interface (I) with ionizing radiation so as to trap at the interface (I) free carriers originating from the pn-type junction or the pin-type structure; d) polarizing the pn-type junction or the pin-type structure so as to apply an electric field within the core (20). Figure 3

The invention provides a rapid growth method for improving the energy resolution of a CdZnTe epitaxial single crystal, and solves the problems of growth process increase, high cost, limited size and limited energy resolution improvement in the existing method for improving the energy resolution of the CdZnTe epitaxial single crystal. The Te powder is uniformly placed around the growth source, the growth temperature is adjusted to control the sublimation rate of the Te powder (namely, the temperature of the upper heating table and the temperature of the lower heating table), the growth of the CdZnTe epitaxial single crystal in the Te atmosphere is realized under the cooperation of the Te powder and the Te powder, and the free carrier concentration and dark current in the epitaxial single crystal can be remarkably reduced, so that the signal-to-noise ratio is improved, and the growth efficiency is improved. And a relatively good energy resolution is obtained.

This invention relates to the field of polymer dielectric materials and discloses a cyclic olefin copolymer / anthracene composite dielectric film for high-temperature energy storage, comprising 100 parts by weight of a cyclic olefin copolymer and 0.2 to 1.0 parts by weight of anthracene. The anthracene is uniformly dispersed in the amorphous network interstices of the cyclic olefin copolymer, utilizing the energy difference between their lowest unoccupied molecular orbitals to construct deep trap sites. By capturing free carriers injected at the electrode interface under high temperature and strong electric field conditions, electron migration is restricted, thereby blocking leakage conduction paths within the bulk phase of the material. This invention effectively reduces Joule heat accumulation during charge transport, improves the high-temperature withstand voltage and insulation reliability of the film, while maintaining relatively low dielectric loss. This all-organic blend system avoids local electric field distortion caused by inorganic filler agglomeration, and the preparation process is simple and mild, facilitating large-scale engineering applications.

The present invention discloses a S / Ku dual-band airborne radome cover structure and a preparation method thereof. The airborne radome cover structure is an A-type honeycomb sandwich structure, which includes an inner skin, a resin film, an adhesive film, a core layer, an adhesive film, a resin layer and an outer skin from the inside to the outside. The adhesive content on the inner side of the inner and outer skins is directionally increased by adding a low-weight resin film on the inner side of the inner and outer skins, and then a layer of low-weight carrier-free adhesive film is used to bond the inner and outer skins to the core layer. This method significantly improves the bonding strength of the interface between the inner and outer skins and the core layer while effectively controlling the adhesive content of the prepreg and the gram weight of the adhesive film. This method uses a hot autoclave heating and pressurizing co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The prepared cover structure is lightweight and uniform, meeting the requirements of lightweight and high wave transmission of the radome.

The invention discloses an interconnection-line-free carrier synchronization method and a carrier synchronization device. The method comprises the following steps: acquiring a voltage signal of a grid-connected point; determining a current voltage phase angle of the grid connection point according to the voltage signal; determining a target voltage phase angle according to the equal interval of the current voltage phase angle; calculating the time difference from the current voltage phase angle to the target voltage phase angle; counting the time difference by using a counting module of which the working frequency is higher than the carrier frequency of the converter, and generating a counting completion signal when the counting meets a preset condition; in response to the counting completion signal, determining a generation moment of the counting completion signal as a carrier synchronization reference moment; and carrying out carrier synchronization on the parallel converters based on the carrier synchronization reference moment. According to the invention, the problem of low precision of a carrier synchronization method without an interconnection line in the prior art can be solved.

This invention discloses a chip-integrated all-optical modulation method based on photogenerated free carriers. The pump light field enters the optical modulator through a directional coupler, generating free carriers through two-photon absorption, which changes the refractive index of the transmission waveguide. The phase of the signal light field changes with the refractive index, achieving effective modulation. This method, based on the relatively mature chip-integrated optical path fabrication process, can be fabricated through a single exposure and etching step. While offering advantages such as high modulation rate, low insertion loss, high mechanical stability, and high fabrication efficiency, it is expected to be widely used in ultra-large-scale chip-integrated optoelectronic systems.

The invention discloses a GaN-based high-power terahertz photoconductive emission system, and relates to the technical field of terahertz technology and radio communication. Comprising a terahertz photoconductive emitter, a bias driving module and an ultraviolet femtosecond pumping module, wherein the terahertz photoconductive emitter comprises a Si-GaN photoconductive substrate and a coplanar strip line electrode structure; the ultraviolet femtosecond pumping module is used as a pumping source, laser irradiates the Si-GaN light guide substrate, and free carriers are excited; the bias driving module is used for driving the free carriers to move at a saturation speed to form instantaneous surge current; and the terahertz photoconductive emitter is used for radiating high-power terahertz waves from the instantaneous surge current through a coplanar strip line electrode structure. The terahertz wave emitter is used for breaking through the performance bottleneck of a traditional emitter and improving the generation efficiency of terahertz waves.

A multilayer semiconductor on insulator structure is provided in which the handle substrate and an epitaxial layer in interfacial contact with the handle substrate comprise electrically active dopants of opposite type. The epitaxial layer is depleted by the handle substrate free carriers, thereby resulting in a high apparent resistivity, which improves the function of the structure in RF devices.

The devices and methods herein relate to a Mie Avalanche Photodiode (Mie-APD). A Mie-APD leverages Mie resonant scattering and avalanche multiplication to generate current. The Mie-APD features a material layer, an absorption region, and a multiplication region. The multiplication region is configured for multiplying free carriers generated when the absorption region absorbs an electromagnetic perturbation. The material layer serves as a substrate for the absorption region and includes the multiplication region. The structure of the Mie-APD allows for the enhancement of spatial resolution, dynamic range, noise characteristics, and data acquisition speed in applications such as hazard detection, 3D sensing, low light imaging, astronomy, and medical imaging, among others. Variations to the structure, design, and fabrication of the Mie-APD can provide further improved performance and functionality such as enhanced response to specific wavelengths and / or polarizations.WO

The utility model provides a high sensitivity detector with internal gain, which comprises a substrate layer and an epitaxial structure which are superposed, the epitaxial structure comprises a charge collection region, a charge control region and an absorption region which are sequentially arranged from the surface of the epitaxial structure far away from the substrate layer to the inside, the charge collection region is used for collecting photon-generated carriers, and the charge control region is used for collecting the photon-generated carriers. The charge control region has a conductivity type opposite to that of the charge collection region, the charge collection region and the charge control region are arranged at a predetermined interval so as to introduce the multiplication region therebetween, and free carriers entering the multiplication region are allowed to initiate an avalanche multiplication effect when the charge control region is in a depleted state. According to the detector, the longitudinal electric field distribution between the multiplication region and the absorption region is optimized, so that the detector has the advantages of high bandwidth, high detection efficiency and low dark current under low working voltage.

The application relates to an optical pulse neuron, which comprises a first wavelength division multiplexer connected with a single-mode optical fiber, the first wavelength division multiplexer being used for inputting excitatory pulse from a neuron dendrite into the optical pulse neuron; a graphene-silicon hybrid waveguide connected with the first wavelength division multiplexer through the single-mode optical fiber, the graphene-silicon hybrid waveguide being used for realizing a pulse firing threshold and generating a pulse. The application utilizes the graphene-silicon hybrid waveguide to make the optical pulse neuron, the graphene-silicon hybrid waveguide can manipulate free carriers at an atomic scale, has the advantages of fast refractory period recovery, low saturated absorption threshold, low pulse emission width and energy, and high pulse firing rate, is an ideal unit for constructing an optical pulse neural network, and is favorable for improving the performance of a photonic SNN.

The utility model provides a semiconductor laser which is provided with an epitaxial layer. The epitaxial layer comprises a p-type waveguide layer, a p-type cladding and an ohmic contact layer. And a grating layer is arranged in the p-type cladding. Wherein the doping concentration of the material of the grating layer is smaller than or equal to the doping concentration of the material of the p-type cladding, and the doping concentration of the p-type cladding is larger than the doping concentration of the p-type waveguide layer. According to the semiconductor laser, the doping concentration of the grating layer is reduced, the absorption level of free carriers is reduced, free carrier absorption is reduced, the band gap difference between the grating layer and the p-type cladding is utilized, the loss type coupling grating is formed, and single longitudinal mode lasing of the semiconductor laser is achieved.

The application provides a semiconductor laser element provided with an ion conjugate layer, and relates to the technical field of semiconductor photoelectric devices, and sequentially comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer from bottom to top; the ion conjugate layer is arranged between the active layer and the upper wave layer and between the active layer and the lower waveguide layer; the ion conjugate layer can improve the molar absorption coefficient and compensate the polarization field, induce local polarization, and then regulate the carrier and Fermi level, improve the small rabbit degeneracy of the laser element, reduce the absorption loss of the free carrier, promote the stimulated radiation to exceed the spontaneous radiation, improve the particle inversion of the non-equilibrium carrier in the resonant cavity of the laser element, reduce the lasing threshold, realize the room-temperature continuous oscillation, improve the slope efficiency of the laser element, reduce the valence band step of the active layer, improve the hole injection efficiency and injection uniformity, and improve the peak gain and gain uniformity of the laser element.

The invention relates to a method for measuring electrical properties of a semiconductor quantum dot material based on free carrier absorption. Comprising the following steps that pumping laser and continuous detection laser are sequentially emitted to the same position of a semiconductor sample to be detected, the power of the pumping laser is changed, the concentration of free carriers is subjected to nonlinear change, the nonlinear characteristic of the free carriers is closely related to the characteristics of excitons and carriers in quantum dots, and the concentration of the free carriers is detected. Transmitting light signal data at different powers are collected through a photoelectric detector, and the obtained data are recorded and processed to obtain electrical characteristic parameters of the detected semiconductor sample. The method is not influenced by the response time or bandwidth limitation of the photoelectric detector, the data processing is simple, and the measurement precision is high; the measuring device is simpler, and the equipment cost is low; the method is wide in application range, can be used for measuring quantum dot materials with deep energy level traps, and is particularly suitable for measuring quantum dot materials with more shallow energy level traps.

The application discloses an electrochromic infrared emissivity transparent thin film device and a preparation method thereof, and the device has the characteristics of visible light transparency and infrared variable emission. The thin film device is prepared through layer-by-layer fine preparation and then sealed and assembled. Specifically, an indium tin oxide nanocrystal (ITO NCs) thin film is used as a positive electrode, a tungsten oxide quantum dot (WO3 QD) layer is used as an ion storage layer, Li + Base organic gel (LiFSI / PC / PMMA) is used as a gel electrolyte to construct a multilayer structure thin film device. The free carrier concentration in the ITO NCs thin film controls the infrared emissivity of the thin film device, has the advantages of fast reaction speed and low required applied voltage, can realize the infrared emissivity of 0.4-0.8 adjustable in the voltage range of-2 V-3 V, and the preparation method has the characteristics of simple operation, easy-to-obtain raw materials and easy popularization.

A method for evaluating the channel interface of a polymer transistor, based on three parameters: total carrier concentration, free carrier concentration, and channel interface trap density, evaluates the quality of the channel interface of a polymer transistor by comparing it with a standard sample, helps to better analyze the device performance, provides theoretical guidance for evaluating the effects of the structure of thin-film transistors, fabrication processes, active layer and gate insulating layer materials, etc. on the electrical performance of the device, and further provides a reference for building an evaluation model for polymer transistor interface analysis in the future.

The present invention discloses a PECVD device for field-effect passivation of crystalline silicon cells, relating to the technical field of crystalline silicon photovoltaic cell production. The polycrystalline silicon (Poly-Si) thin film structure comprises two low-concentration doped regions and two high-concentration doped regions, which are stacked layer by layer. By stacking the low-concentration doped regions and the high-concentration doped regions layer by layer, the present invention allows free carriers in the high-concentration doped regions to diffuse into the low-concentration doped regions, leaving behind charged fixed ions, thus transforming the high-concentration doped regions into high-net-charge regions. The low-concentration doped regions have high crystallinity and high carrier mobility, and suppress the diffusion of impurity atoms. By providing the high-net-charge regions, enhanced field-effect passivation is achieved, thereby improving the efficiency of crystalline silicon photovoltaic cells.