16 results about "Thin crystal" patented technology

The invention discloses a mid-infrared nonlinear crystal, a mid-infrared laser and a preparation method of the mid-infrared nonlinear crystal, a slice crystal is adopted, an included angle theta is formed between an optical axis Z axis of the slice crystal and the surface, the slice crystal is polarized into a periodic polarization structure with the period of lambda through a room temperature electric field polarization technology, and a large surface forms an optical plane through polishing. The problem of how to reduce the thermal lens effect of the intermediate infrared nonlinear crystal is solved, and the damage threshold of the intermediate infrared nonlinear crystal can be improved, so that the laser output power is improved.

This application discloses a method and device for fabricating a periodically polarized ultrathin lithium niobate / lithium tantalate device, belonging to the field of nonlinear optical device manufacturing. The method includes: fabricating and polarizing periodic electrodes on a provided ferroelectric crystal wafer to form a periodically polarized master wafer; bonding the master wafer to a carrier substrate using optical resin-assisted bonding or direct bonding to form a composite structure; thinning and polishing the side of the master wafer away from the carrier substrate to obtain an ultrathin periodically polarized crystal functional layer; and fabricating the structure of the ultrathin periodically polarized crystal functional layer to obtain a periodically polarized ultrathin lithium niobate / lithium tantalate device. This method avoids the inherent problems of high-voltage breakdown and poor domain quality in existing technologies when directly polarizing ultrathin crystals by placing the high-risk polarization step on a thick, stable wafer.

The invention discloses a photoelectric detector based on two-dimensional / three-dimensional perovskite lamination and a preparation method thereof, and belongs to the technical field of photoelectric detectors. The photoelectric detector is composed of a heterojunction structure, an electron transport layer, a hole transport layer, a transparent electrode and a metal electrode, wherein the heterojunction structure is prepared by combining MAPbI3 perovskite thin single crystals and two-dimensional BA2PbI4, and the electron transport layer, the hole transport layer, the transparent electrode and the metal electrode are located on the two sides. According to the method, an opening is controlled through silica gel sealing on a perovskite thin single crystal growth device, a solvent is slowly volatilized at a certain temperature to prepare seed crystal grains, then the temperature is increased for continuous growth until the size is proper, and single crystal preparation is completed. According to the method, the MAPbI3 perovskite single crystal with good crystallinity and regular morphology and the BA2PbI4 thin crystal which grows rapidly and is prepared uniformly can be prepared, the acetonitrile and the BA2PbI4 can doubly passivate MAPbI3, and the obtained detector can effectively reduce dark current and obtain good photoelectric detection performance.

The application provides a preparation method and a centering device of a size-controllable ultrathin high-quality echo wall optical crystal microcavity, and the method comprises the following steps: cutting a crystal material into a wafer and grinding and thinning the crystal thickness by using a polishing disc; placing an optical crystal microcavity blank on a microscope stage, adjusting two-dimensional adjustment knobs of the stage, and making the center of the optical crystal microcavity blank coincide with an origin of an objective micrometer scale; making a clamping rod with an adhesive adhered to a bottom end penetrate a top end through hole of a clamping rod fixing frame, and making the clamping rod align with the origin of the objective micrometer scale; adjusting the height of the clamping rod, making the optical crystal microcavity blank be pasted and fixed on the bottom end of the clamping rod by ultraviolet curing glue, and completing centering; taking the clamping rod off the clamping rod fixing frame, chamfering an outer circle of the optical crystal microcavity blank; grinding the outer circle surface of the optical crystal microcavity wafer by using sandpaper; polishing the optical crystal microcavity wafer, and obtaining the optical crystal microcavity based on the polished optical crystal microcavity wafer.

The invention discloses a thin crystal ingot resistivity detection method based on an eddy current method probe, which relates to the technical field of semiconductor measurement, solves the problem that the measurement of the corresponding resistivity of a thin crystal ingot to be detected has deviation under partial circumstances, and comprises the following steps: performing electrical detection on the thin crystal ingot to be detected, and analyzing to obtain the calculated surface resistivity of the thin crystal ingot to be detected; based on the calculated surface resistivity of the to-be-measured thin crystal ingot, the thin crystal ingot type of the to-be-measured thin crystal ingot is identified, and the skin depth of the to-be-measured thin crystal ingot is calculated in combination with the skin effect; setting a plurality of groups of contrast thin crystal ingots similar to the thin crystal ingot to be tested, testing the plurality of groups of contrast thin crystal ingots by an eddy current method, and calculating compensation coefficients of the contrast thin crystal ingots based on test results; and calculating a fitting equation based on the compensation coefficient, writing the fitting equation into an upper computer, and calculating the actual resistivity of the to-be-measured thin crystal ingot in combination with the fitting equation, so that accurate measurement of the corresponding resistivity of the to-be-measured thin crystal ingot is realized, and automatic and intelligent measurement of the corresponding resistivity of the to-be-measured thin crystal ingot is also realized.

This invention discloses a multi-stage cascaded laser frequency doubling device, belonging to the field of laser frequency doubling technology. It includes a front-end frequency doubling module and at least one cascaded frequency doubling module arranged sequentially along the optical path. The cascaded frequency doubling module includes a second-harmonic crystal, a third-harmonic crystal, a beam splitter, a delay adjustment device, and a beam combiner. The front-end frequency doubling module, beam splitter, second-harmonic crystal, beam combiner, and third-harmonic crystal are connected sequentially. By extending the multi-stage continuous cascaded crystal architecture, the long crystal is split into a sequence of thin frequency doubling crystals, suppressing time drift and pulse broadening. Each stage is equipped with a multi-band fully transparent film system to reduce dispersion. Furthermore, a beam splitting and beam combining bypass and dynamic time delay compensation are designed to achieve precise spatiotemporal beam combining of ultraviolet light, enabling femtosecond lasers to possess both high efficiency, low broadening, and excellent pulse quality.

A flexible, non-flat solar cell comprises a flexible substrate. A pn junction is on or in the flexible substrate. The solar cell has been flexed so as to have a non-flat geometry that results in an increased surface area of the flexed solar cell with respect to the surface area of a flat solar cell that is the same as the flexed solar cell except that the flat solar cell has a flat surface geometry that has the same projected area on a lateral plane as does the flexed solar cell.

This invention provides a method and system for analyzing the surface shape changes of coatings on ultrathin crystal devices based on finite element analysis, belonging to the field of data processing technology. The method includes: calculating the displacement gradient tensor of subdomain elements to obtain entropy correction coefficients; correcting the amplitude of a uniformly distributed mechanical load based on the entropy correction coefficients to obtain a final uniformly distributed mechanical load; reloading the final uniformly distributed mechanical load into a numerically corrected configuration, repeating the solution and load correction process until the absolute difference of the entropy correction coefficients between two adjacent iterations is less than a preset tolerance, obtaining a final convergent potential field; and extracting the nodal displacement distribution on the substrate surface based on the final convergent potential field to obtain the surface shape change result. This invention can more accurately solve the displacement field and surface shape changes of ultrathin crystal devices after coating, effectively improving the convergence stability and numerical reliability of surface shape analysis.

The application discloses an ultrathin defect-free ZIFs@GO composite film, a preparation method and application thereof, and comprises the following steps: 1) preparing GO by a modified Hummers method; 2) depositing GO on a polymer base film to prepare a GO composite film; and 3) growing ZIFs coordination polymers on the GO composite film by an interfacial counter-diffusion method to prepare the composite film. The application optimizes the ZIFs synthesis conditions and reduces non-selective defects to improve the separation performance of the ZIFs film. In the reverse diffusion process, GO acts as a barrier to make the precursor diffuse along the interlamellar gap and greatly slow down the diffusion rate; by optimizing the driving force of diffusion in the solution, the ZIFs crystallization rate can be accurately matched, the ZIFs growth content can be effectively reduced, and the generation of intercrystalline defects can be reduced. The GO lamella is rich in oxygen functional groups, which provides sites for the heterogeneous nucleation of ZIFs, especially at the edges and defects of the GO lamella, so that the non-selective defects in the GO film can be effectively reduced; meanwhile, the nanoscale limitation enables the ZIFs heteroepitaxial growth to be carried out along the two-dimensional channel instead of the vertical direction, which is beneficial to the formation of an ultrathin crystal structure and realizes the preparation of the ultrathin defect-free composite film.

The invention belongs to the technical field of photoelectric detection, and discloses a semimetal MoTe2 modification method and a semimetal MoTe2-based photoelectric detector, and the method comprises the steps: laying a semimetal MoTe2 crystal on a 3M adhesive tape, and pressing the crystal; repeatedly tearing and pasting the 3M adhesive tape for 4-6 times; pasting the film on a glass slide; aligning a 3M adhesive tape with the thin film and pasting; quickly tearing off the 3M adhesive tape; pasting the thin film on the silicon wafer and heating; slowly lifting the film; the method comprises the following steps: irradiating MoTe2 nano thin crystals on a substrate by using 266nm Q-switched laser to obtain modified semimetal MoTe2; preparing a nickel / gold electrode on the silicon dioxide substrate to obtain a substrate I; and combining the modified MoTe2 nano thin crystal with the substrate I to obtain the photoelectric detector. The preparation process is simple, the photoelectric property is obviously improved, and the prepared photoelectric detector can realize high responsivity and sensitivity in a wide spectrum range.

The utility model relates to the field of fine crystal bar machining auxiliary devices, in particular to a diameter fine crystal bar machining auxiliary tool. Comprising a placing plate, a plurality of rolling wheels are installed on the lower surface of the placing plate, a fixing plate is installed on the upper surface of the placing plate, a moving device is installed on one side of the fixing plate, a handle is fixedly connected to the other side of the fixing plate, an adjusting structure is arranged on the inner wall of the placing plate, and the adjusting structure comprises an auxiliary plate. The auxiliary plate is slidably connected with the placing plate, a plurality of connecting holes are formed in the two sides of the auxiliary plate, the two sides of the placing plate are fixedly connected with two positioning plates, and the inner walls of the two positioning plates are rotatably connected with the same screw rod. According to the auxiliary tool for machining the diameter fine crystal bar, the area of the placing plate can be increased, so that the fine crystal bar is more stable in the placing process, the fine crystal bar is prevented from being suspended, and the safety of the fine crystal bar is further improved.

The invention relates to the technical field of zeolite molecular sieves, and discloses a secondary crystallization modified Ti-ITQ-24 zeolite molecular sieve and a preparation method and application thereof.The secondary crystallization modified Ti-ITQ-24 zeolite molecular sieve is prepared from Ti-ITQ-24 raw powder, alkali, an aluminum source and water through a secondary crystallization reaction, and the secondary crystallization modified Ti-ITQ-24 zeolite molecular sieve is prepared through the secondary crystallization reaction; alkali can dissolve a framework and introduce Al to achieve secondary crystallization, Ti distribution can be effectively improved, the mesopore amount can be effectively increased, a peptide silicon aluminum structure with thinner crystal grain shape and more uniform Ti distribution can be prepared after secondary crystallization, the titanium silicon framework and amorphous TiO2 can be effectively dissolved by using the alkali, and the problem of slow mass transfer caused by pore channel blockage is solved. By introducing Al, the hydrophilicity of the molecular sieve can be effectively improved, the molecular sieve can better adapt to a heterogeneous ammoximation reaction system, and the water-oil two-phase mass transfer efficiency is improved, so that the conversion rate and selectivity of the heterogeneous ammoximation reaction are improved.

The application belongs to the technical field of photoelectric detection, and discloses a semi-metal MoTe2 modification method and a photoelectric detector based on semi-metal MoTe2. The semi-metal MoTe2 crystal is laid on a 3M adhesive tape and pressed. The 3M adhesive tape is repeatedly torn and pasted 4-6 times. The film is pasted on a glass slide. The 3M adhesive tape is aligned with the film and pasted. The 3M adhesive tape is quickly torn off. The film is pasted on a silicon wafer and heated. The film is slowly lifted. MoTe2 nanometer thin crystals on the substrate are irradiated by 266nm Q-switched laser to obtain modified semi-metal MoTe2. A nickel / gold electrode is prepared on a silicon dioxide substrate to obtain a substrate I. The modified MoTe2 nanometer thin crystals are combined with the substrate I to obtain a photoelectric detector. The preparation process is simple, the photoelectric performance is significantly improved, and the prepared photoelectric detector can realize high responsivity and sensitivity in a wide spectral range.

The invention discloses an ultrathin ZnTe crystal for broadband terahertz generation and detection and a preparation method and application thereof, and relates to the technical field of crystal material processing. The method comprises the following steps: chamfering the edge of a ZnTe single crystal wafer, and thinning the ZnTe single crystal wafer in combination with mechanical grinding and polishing; aiming at the high surface quality requirement and the soft and brittle characteristics of the ZnTe crystal, a pressure-controlled double-sided polishing method is adopted during thinning, and the ultrathin ZnTe crystal and the crystal frame for terahertz application are processed. Compared with other traditional processing technologies, the method has the advantages that the ultrathin ZnTe wafer with the thickness of 50 microns or below can be processed, additional accompanying wafers are not needed, the problem that the ultrathin ZnTe crystal is fragile in the transportation and testing process is solved, and the requirements for broadband terahertz generation and detection at present are effectively met.

This invention relates to the field of molecular sieves, specifically to an SCM-36S molecular sieve, its preparation method, applications, compositions, and methanol conversion methods. This molecular sieve exhibits specific X-ray diffraction pattern characteristics. The SCM-36S molecular sieve with the X-ray diffraction pattern characteristics of this invention has thin crystal thickness, large external specific surface area, high acidity, high concentration of strong acids, and rapid molecular diffusion, resulting in high activity and stability. Using the molecular sieve of this invention in alkylbenzene cracking reactions or methanol conversion to olefins and / or aromatics yields high reactant conversion rates, product yields, and long service life.

The application discloses a time-domain spectrum system capable of generating and detecting ultra-wideband terahertz pulses. The system comprises a laser light source, a light splitting module, an optical path adjustment coupling module, a terahertz emission module, a sample detection module and an electro-optic sampling module. After the laser pulses output by the laser light source are split, the pump light is chopped, modulated, expanded and irradiated to a spin terahertz emitter to generate ultra-wideband terahertz pulses of 0.1-10 THz. After the terahertz pulses interact with the sample through a confocal off-axis parabolic mirror, the terahertz pulses are collimated and output again. The detection light formed by light splitting is adjusted in optical path and coincides with the terahertz pulses in time and space, and is focused on an ultra-thin ZnTe crystal in the <110> crystal direction. Finally, the terahertz time-domain signal is obtained through electro-optic sampling. The system has the functions of emitting and detecting ultra-wideband terahertz pulses, and can be used not only in the fields of material detection and physicochemical analysis, but also in the precise verification of the characteristics of other terahertz sources and detection crystals.