155results about How to "Reduce dark current" patented technology

The invention relates to a backside illuminated image sensor and a preparation method thereof, and electronic equipment, and relates to the technical field of integrated circuits, the backside illuminated image sensor comprises a substrate, and photodiodes and laminated target isolation structures which are located on a first surface of the substrate, are alternately arranged along a first direction parallel to the first surface, and extend towards the substrate; the substrate internally comprises a plurality of trench isolation structures which extend into the substrate through the first surface and are arranged at intervals in the first direction; the trench isolation structures and the laminated target isolation structures right above the trench isolation structures are arranged in a one-to-one manner; the laminated target isolation structure comprises isolation parts and insulation parts which are sequentially and alternately laminated along a second direction deviating from the substrate; the photodiode comprises at least two photosensitive layers which are sequentially stacked in the second direction, the longitudinal sections of the photosensitive layers are T-shaped, one photosensitive layer makes contact with the first surface of the substrate, substrate damage caused by ion implantation can be avoided, and meanwhile the photoelectric conversion efficiency and the quantum efficiency are improved.

The invention discloses a TOPCon battery capable of reducing UV attenuation and a preparation method thereof, and belongs to the field of TOPCon batteries, the TOPCon battery comprises a silicon substrate, and three silicon nitride layers / two silicon oxynitride layers / one silicon oxide layer are sequentially deposited on the front surface of the treated silicon substrate to form a front surface antireflection layer; and depositing three silicon nitride layers on the back of the silicon substrate to form a back antireflection layer. The polycrystalline solar cell has the advantages that three silicon nitride layers / two silicon oxynitride layers / one silicon oxide layer are arranged on the front face of the silicon substrate to serve as the front face antireflection layer, the color stability is high, the surface of the silicon substrate can be better passivated, light reflection can be better reduced, the open-circuit voltage and the short-circuit current of the polycrystalline solar cell are improved, and the service life of the polycrystalline solar cell is prolonged. Therefore, the photoelectric conversion efficiency of the polycrystalline solar cell is effectively improved.

The invention relates to a Ga2O3 / MgO / Si avalanche heterostructure and preparation thereof, and belongs to the technical field of semiconductor devices. In order to improve the epitaxial quality of a Ga2O3 film on the Si substrate, guarantee good energy band arrangement and charge transmission and improve the avalanche gain of the Ga2O3 / Si heterojunction, the invention provides a Ga2O3 / MgO / Si avalanche heterojunction design which is focused on the fact that Si and Ga2O3 are combined to form the heterojunction, and the avalanche gain of the Ga2O3 / MgO / Si avalanche heterojunction is improved. The integration level and the universality of the Ga2O3-based solar-blind ultraviolet photoelectric detector are enhanced, and avalanche gain is provided for the detector by adding the MgO barrier layer. The preparation is simple, the optical gain and the sensitivity are ideal, and Si is used as a substrate, so that the integration and the processing of a subsequent CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process are facilitated.

The invention discloses a two-dimensional organic-inorganic hybrid perovskite and molybdenum diselenide heterojunction photoelectric detector and a preparation method thereof. The photoelectric detector comprises a substrate; the electrode layer is positioned on one side of the substrate; the photoelectric conversion part is arranged on the side, away from the substrate, of the electrode layer, and materials of the photoelectric conversion part comprise two-dimensional organic and inorganic hybrid perovskite (C6H13NH3) 2PbI4 (C6PI), molybdenum diselenide (MoSe2) and a protective layer hexagonal boron nitride (h-BN). According to the invention, by constructing the heterostructure, the advantages of high absorption coefficient and extremely low dark current of the two-dimensional perovskite material and the advantages of high carrier mobility and wide light response range of the two-dimensional transition metal disulfide are combined, so that the performance of the photoelectric detector is improved to a great extent; the method has good performance in the aspects of light response rate, response time, response range and the like.

The invention relates to the field of semiconductor material molecular beam epitaxial growth manufacturing, and discloses a method for controlling As background pressure to reduce InAs / GaSb surface defects, which comprises the following steps: S1, substrate preparation and pretreatment: selecting a proper GaSb single crystal substrate, and carrying out selection, cleaning, degassing and deoxidation treatment on the GaSb substrate; s2, carrying out epitaxial growth of a GaSb buffer layer, and carrying out epitaxial growth of the GaSb buffer layer on the processed GaSb substrate; s3, control of As background pressure intensity: in the growth process of the GaSb buffer layer, the As background pressure intensity in the cavity is controlled and stabilized by adjusting the opening degree of an As needle valve; s4, growth of an InAs / GaSb superlattice: growing an InAs and GaSb superlattice structure layer by layer under the condition of well controlled As background pressure intensity. By accurately controlling the As background pressure intensity, the'bright spot 'defect and other surface defects formed on the InAs / GaSb surface can be effectively reduced, and the surface quality of the superlattice material is improved.

The invention discloses a high-density perovskite thin film, a preparation method and application of the high-density perovskite thin film in X-ray detection. The preparation method of the high-density perovskite thin film comprises the following steps: coating an electron transport layer with a precursor stock solution containing a perovskite material and an auxiliary crystallization additive, and then drying. The perovskite material is selected from one or more of FACs2AgBiBr6, FAMACsPbBr3, CsPbBr3, MAPbBr3, Cs2AgBiBr6 and MAPbI3, and the perovskite material is selected from one or more of FACs2AgBiBr6, FAMACsPbBr3, CsPbBr3 and MAPbI3; the auxiliary crystallization additive is selected from thiourea, biuret, ammonium chloride and the like; the precursor solvent is selected from dimethyl sulfoxide, dimethyl formamide and the like. By adding the auxiliary crystallization additive, homogeneous crystallization of perovskite is promoted, and the prepared film has high compactness, low defect rate, flat surface and controllable thickness, and is suitable for large-area devices.

The invention relates to the technical field of solar-blind ultraviolet detector materials, and particularly discloses a diamond / gallium oxide heterojunction and application of the diamond / gallium oxide heterojunction to a solar-blind ultraviolet detector, and the diamond / gallium oxide heterojunction comprises a single crystal diamond layer and a Zr-doped epsilon-Ga2O3 layer located on the single crystal diamond layer; the single crystal diamond layer is made of (100) oriented single crystal diamond, and the surface roughness RMS of the single crystal diamond is 2-6 nm; the Zr-doped epsilon-Ga2O3 layer is Zr-doped epsilon-Ga2O3 which is grown on the surface of the monocrystal diamond in a heteroepitaxial manner by adopting a pulse laser deposition method; zr-doped epsilon-Ga2O3 grows on the surface of the monocrystal diamond along the (001) direction; and the Zr doped epsilon-Ga2O3 is of a columnar crystal structure. The heterojunction provided by the invention realizes excellent photoelectric detection performance, solves the problem of poor selectivity of a traditional solar blind ultraviolet detector, and has wide application value.

The invention discloses a method for forming an image sensor. The method comprises the following steps: providing a substrate; forming a trench isolation structure and a photodiode on the front surface of the substrate; forming a grid electrode of a transfer transistor of which at least part of a channel is in the vertical direction above the photodiode; injecting a first doped region of a first conductive type on the front surface of the substrate; and by controlling the voltage of the grid electrode, the charge of the photodiode is transmitted to the first doped region through a part of the substrate between the second doped region of the second conduction type of the photodiode and the grid electrode of the transfer transistor. According to the embodiment of the invention, the position of the grid electrode of the transfer transistor is close to the isolation structure, and the characteristic of high-concentration doping of the second doped region of the second conduction type of the photodiode is utilized, so that a charge transfer channel of the photodiode is more easily turned off, and backflow and dark current in the photodiode are reduced; in addition, a fully-depleted transmission channel can be formed, and the transmission capacity of charges is improved.

The invention relates to the technical field of semiconductors, and discloses a PN junction material carrier concentration and mobility test method and application. The test method comprises the following steps: carrying out a Hall test on an N-type substrate to obtain the carrier concentration n and mobility mu n of the N-type substrate; p-type ions are doped on the N-type substrate to form a P-on-N structure sample, the sample is subjected to a Hall test, and the Hall coefficient Rh and the resistivity rho are measured; corroding the P-on-N structure sample by the corrosive liquid to form an inclined table surface, and measuring the corrosion depth h; determining the junction depth by using an IV curve, and obtaining the thickness dp of a P layer and the thickness dn of an N-type layer; and substituting into a calculation formula to obtain the P-type carrier concentration p and the P-type carrier mobility mu p. According to the PN junction material testing method, the concentration and mobility of bipolar carriers of electrons and holes can be effectively tested, the testing method is simple, errors are small, and the problems that the P-type concentration cannot be measured due to inaccurate carrier measurement, the testing process is tedious and the like can be effectively solved.

The invention relates to the field of semiconductor heterojunction photoelectric detectors, in particular to a bias voltage adjustable photoelectric detector and a preparation method and application thereof.The detector sequentially comprises a substrate, a buffer layer, a p-type wide bandgap semiconductor layer and a p-type narrow bandgap semiconductor layer from bottom to top, the p-type narrow bandgap semiconductor layer partially covers the p-type wide bandgap semiconductor layer, and the p-type narrow bandgap semiconductor layer covers the p-type narrow bandgap semiconductor layer. The detector further comprises a first metal electrode and a second metal electrode, the first metal electrode is arranged on the p-type wide bandgap semiconductor layer, the second metal electrode is arranged on the p-type narrow bandgap semiconductor layer, the first metal electrode does not make contact with the p-type narrow bandgap semiconductor layer, and the second metal electrode does not make contact with the p-type narrow bandgap semiconductor layer. The forbidden band width of the p-type wide forbidden band semiconductor layer ranges from 3.1 eV to 5 eV, and the forbidden band width of the p-type narrow forbidden band semiconductor layer ranges from 0.3 eV to 1.2 eV. The prepared detector is high in sensitivity, low in power consumption and simple in structure, and can be applied to photoelectric detection.

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.

A light detection element with reduced dark current and improved external quantum efficiency. The light detection element comprises: an anode; a cathode; and an active layer disposed between the anode and the cathode and comprising a p-type semiconductor material and an n-type semiconductor material, wherein the thickness of the active layer is greater than 800 nm, and the value obtained by subtracting the absolute value of the LUMO of the n-type semiconductor material from the work function of the surface in contact with the cathode side surface of the active layer is 0.0 to 0.5 eV. In addition, the above-mentioned n-type semiconductor material has an absolute value of the LUMO of 2.0 eV to 10.0 eV.

The invention relates to a method for preparing a low dark current silicon drift detector based on a double-sided temporary bonding process, which comprises the following steps of: after a front surface process of an SDD wafer is finished, carrying out temporary bonding on the front surface of the SDD wafer by adopting a temporary bonding adhesive and a temporary bonding glass slide; thinning and polishing the back surface of the SDD wafer after the temporary bonding is completed, and carrying out a CMP (Chemical Mechanical Polishing) process on the back surface of the SDD wafer after the thinning and polishing to eliminate a damaged layer and reduce the dark current of a device; then, process manufacturing is carried out on the back face of the SDD wafer, after manufacturing is completed, the glass sheet and the SDD wafer are stripped off through a laser debonding process, and the front face of the wafer is exposed; when the active region of the SDD wafer is manufactured, a thin gate oxide layer is adopted for doping for shielding injection, the shielding oxide layer is removed after injection is completed, furnace tube oxidation and annealing are carried out, and the dark current of a device is reduced; when the oxide layer of the SDD contact hole is removed, a manufacturing process combining dry etching and wet etching is adopted, so that damage to a silicon substrate is avoided, and dark current of a device is reduced.

The invention discloses a dark current suppression method of a gold-doped lead sulfide colloid quantum dot photoelectric detector, and relates to a quantum dot technology. According to the method, a gold electrode is grown on a quartz substrate through magnetron sputtering to serve as a bottom electrode of the device. The preparation method comprises the following steps: spin-coating an Au NP-doped lead sulfide quantum dot solution on a gold electrode, covering an EDT solution on a quantum dot film to perform ligand exchange, spin-drying the quantum dot film on a spin-coating machine after ligand exchange, and washing residual ligands for multiple times in spin-coating by adopting a methanol solution. The PbS-EDT spin-coating step is repeated to stack the lead sulfide quantum dots, so that a compact quantum dot thin film is obtained to serve as a light absorption layer, then a zinc oxide thin film is grown on the lead sulfide thin film through magnetron sputtering to serve as an electron transport layer, and then high-transmittance low-resistance ITO is continuously grown through magnetron sputtering to serve as a top electrode of the device. According to the method, low-cost solution processing of the photosensitive layer of the device is achieved, batch preparation can be achieved, and the photoelectric property is improved through doping of gold nanocrystals.

This invention discloses a deep trench isolation structure for a CIS (CMOS Image Sensor), comprising: a deep trench formed by plasma etching of a first surface of a first semiconductor substrate, wherein the inner surface of the deep trench has interface defects generated by plasma etching; a first semiconductor epitaxial layer, a second dielectric layer, and a third conductive material layer formed in the deep trench; and a fourth conductive material layer formed in a portion of the deep trench closest to the peripheral region; the fourth conductive material layer being connected to an external electrode; the external electrode being connected to an external control module, which provides an external voltage to each of the third conductive material layers to modulate the interface states of the inner surface of the deep trench, thereby eliminating the adverse effects of interface defects on the interface states. This invention also discloses a method for manufacturing the deep trench isolation structure for a CIS. This invention can modulate the interface states at the interface between the deep trench isolation structure and the semiconductor substrate, optimizing the interface states and thereby reducing dark current and white pixels.

The invention belongs to the technical field of semiconductors, and particularly relates to a method for reducing dark current of an aluminum gallium nitrogen ultraviolet photoelectric detector, which comprises the following steps: immersing a pre-cleaned sapphire substrate in a mixed solution for oxidation etching, the solution being a mixed solution of an oxidizing agent and an etching agent; the etched sapphire template is taken out, washed for a period of time and dried; transferring the dried sapphire into hydride vapor phase epitaxy equipment, keeping for a period of time at high temperature in a mixed atmosphere, and then epitaxially growing an aluminum-gallium-nitrogen epitaxial layer to form an aluminum-gallium-nitrogen / sapphire template; and preparing the ultraviolet photoelectric detector on the aluminum gallium nitride / sapphire template through ultraviolet lithography and electron beam evaporation processes. The method provided by the invention can effectively remove silicon pollutants at the growth interface of aluminum gallium nitrogen and sapphire and reduce interface leakage current caused by silicon impurities, so that the dark current of the aluminum gallium nitrogen ultraviolet photoelectric detector is remarkably reduced.

The present invention relates to a large-area halide perovskite single crystal heterojunction and a growth method thereof and an application in a nuclear radiation detector. The growth method of the large-area halide perovskite single crystal heterojunction comprises the following steps: placing a pretreated cesium-bromine-lead or cesium-bromine-bismuth substrate in a reagent bottle containing a perovskite precursor solution, and then sealing it; fixing the sealed reagent bottle in a water tank, and performing epitaxial growth of a large-area halide perovskite single crystal film on the substrate by an inversion crystallization method or a cooling crystallization method to obtain a large-area halide perovskite single crystal heterojunction. The method of the present invention has the advantages of low cost, simplicity and high efficiency; the perovskite single crystal heterojunction detector of the present invention can effectively suppress the dark current drift caused by ion migration under reverse bias, thereby obtaining a detection effect with high sensitivity and low detection limit.

The invention discloses a long-wave class-II superlattice SF6 gas detector which comprises a focal plane array, the focal plane array comprises a plurality of independent photosensitive pixels, the focal plane array and a reading circuit are connected to form an infrared focal plane detector assembly, and each photosensitive pixel comprises a GaSb substrate. The GaSb buffer layer, the n InAsSb buffer layer, the n-type lower ohmic contact layer, the n-type InAs / GaSb intrinsic second-class superlattice light absorption layer, the AlGaAsSb barrier layer and the n-type upper ohmic contact layer are sequentially arranged on the GaSb substrate; partial region of each layer of epitaxial material is etched to the bottom n-type contact layer to form a bottom electrode window, and partial region of each layer of epitaxial material is etched to the top n-type contact layer to form a top electrode window; an Au nano array is prepared on the n-type upper ohmic contact layer to serve as a plasmon structure; a bottom annular electrode is deposited and prepared on the bottom electrode window, and a top electrode is deposited and prepared at the top electrode window, so that the SF6 gas can be accurately and efficiently monitored in a non-contact, real-time and long-distance manner, and the leakage point of the SF6 gas can be quickly and accurately searched.

The application discloses a kind of image sensor preparation method and image sensor, belong to semiconductor technical field.The application is formed P-type heavily doped region below floating diffusion portion, make the depletion region of P-type heavily doped region and N-type lightly doped region below floating diffusion portion from the original four square trapezoidal curve as half moon type, make the area of this depletion region fall in shallow trench isolation structure smaller, achieve the purpose of reducing dark current.At the same time, by etching and low-temperature epitaxial growth process, the diffusion of P-type heavily doped region is limited, so that the P-type heavily doped region is limited in the area away from the shallow trench isolation structure, and the lateral area of P-type heavily doped region is smaller than N-type lightly doped region.Because the electric field of P-type heavily doped region in vertical direction is much stronger than the electric field in horizontal direction, so as to reduce the electric field intensity in horizontal direction close to the shallow trench isolation structure, so that the defects capable of playing the role of recombination center can absorb relatively less electrons or holes than the original structure, thereby achieving the effect of reducing dark current.

The invention discloses a PIN photoelectric detector based on epitaxial Ge on Si and a preparation method, and relates to the technical field of semiconductor photoelectric devices. The intrinsic Ge epitaxial layer is positioned on the upper surface of the N-type Si substrate; the P-type Ge region is positioned in the intrinsic Ge epitaxial layer and is close to the upper surface of the intrinsic Ge epitaxial layer; the first metal electrode and the second metal electrode are in ohmic contact with the P-type Ge region and the N-type Si substrate respectively. The intrinsic Ge layer is epitaxially grown on the N-type Si substrate to serve as an absorption region, a Si / Ge heterojunction PIN structure is constructed, and reverse injection of carriers is effectively inhibited by utilizing an energy band potential barrier of the Si / Ge heterojunction, so that the dark current of the device is remarkably reduced. Meanwhile, by accurately controlling the thickness of the intrinsic Ge epitaxial layer, the bandwidth and the responsivity of the device can be flexibly balanced so as to meet the requirements of different application scenes such as high-speed communication or high-sensitivity detection.

The invention provides a preparation method of a tin-doped scaly nano gallium oxide thin film solar blind ultraviolet photoelectric detector. The preparation method comprises the following steps: carrying out cleaning pretreatment on a single crystal GaN substrate; depositing an Au thin film on the pretreated single crystal GaN substrate to serve as a catalyst layer; the preparation method comprises the following steps: mixing Ga2O3, diamond and SnO2 powder according to a certain mass ratio to prepare a precursor; putting the single crystal GaN substrate deposited with the Au thin film and a precursor into a CVD furnace, and growing according to preset gas flow, pressure intensity, reaction temperature and reaction time to obtain a tin-doped scaly nano gallium oxide thin film; and respectively preparing electrodes on the surface of the tin-doped scaly nano gallium oxide thin film and the surface of the GaN substrate by adopting a radio frequency magnetron sputtering method. The conductivity of the thin film is improved through tin doping, the specific surface area and light absorption are increased through the scaly nanostructure, high-performance deep ultraviolet photoelectric detection is achieved, and the technical problem that in the prior art, the dark current of a device is high is solved.

The invention provides a semiconductor image sensor device which suppresses the generation of leakage current caused by the interface level and operates stably without reducing the detection sensitivity of a photodiode. A first buried well layer (102-1) and a second buried well layer (102-2) are provided on the front surface side of a silicon support substrate (101), the first buried well layer (102-1) having a first impurity concentration of a second conductivity type at a first position (A) that becomes the back gate of a MOS transistor element (114), and the second buried well layer (102-2) having a second impurity concentration of a second conductivity type at a second position (A) that becomes the back gate of the MOS transistor element (114). The second buried well layer (102-2) has a first impurity concentration of the second conductivity type at a second location (B) spaced apart from the first location (A) and not opposite the back gate; a third buried well layer (103), which is separated from the first buried well layer (102-1) by a predetermined distance in the first direction and the second direction, is formed close to the second buried well layer (102-2), surrounds the first buried well layer (102-1) from both sides, and has a second impurity concentration of the first conductivity type; and a fourth buried well layer (104) which is formed so as to be in contact with the bottom surfaces of the first buried well layer (102-1) and the third buried well layer (103) at a position deeper than the first buried well layer (102-1), and which has a third impurity concentration of the first conductivity type.

The embodiment of the invention provides an avalanche photodetector and a preparation method thereof. The avalanche photoelectric detector comprises an avalanche photodiode and an extraction structure. The avalanche photodiode comprises a first contact layer, a charge layer, a light absorption layer and a second contact layer which are arranged in sequence. The first contact layer and the extraction structure have a first doping type, the charge layer and the light absorption layer have a second doping type, the first doping type is different from the second doping type, and the first contact layer, the charge layer, the light absorption layer and the second contact layer jointly form a first electric field; the extraction structure is located on the outer side of the avalanche photodiode in the second direction, the extraction structure and the light absorption layer jointly form a second electric field, and the first direction intersects with the second direction; the first electric field is not in contact with the second electric field. An extraction structure is introduced to the outer side of an electric field region of an original avalanche photodetector, the extraction structure can attract carriers on the outer side, the situation that the carriers diffuse into the electric field region to introduce additional diffusion current is reduced, and therefore device noise is reduced.

The utility model discloses a tensile strain germanium substrate and a tensile strain germanium sensor, which can be used in the field of semiconductors. The tensile strain germanium substrate comprises a first silicon substrate, a first intrinsic strain germanium layer, an intrinsic strain germanium / germanium-silicon multi-quantum well layer, a second intrinsic strain germanium layer, a second doped strain germanium layer, a ferroelectric oxide layer and a dielectric layer which are stacked in sequence; the diameter of the first silicon substrate is not less than 8 inches. Therefore, according to the germanium-based sensor manufactured based on the tensile strain germanium-based substrate, on one hand, the ferroelectric oxide has a negative capacitance effect, so that relatively large positive capacitance in a thick germanium vertical PIN structure can be effectively compensated, the capacitance of the whole germanium-based sensor is reduced, and meanwhile, high responsivity and high working speed of the germanium-based sensor are realized; and on the other hand, two photoelectric sensing layers including the second intrinsic strain germanium layer and the intrinsic strain germanium / germanium-silicon multi-quantum well layer exist, and the spectral response range of the germanium sensor can be remarkably expanded through the combined structure of the second intrinsic strain germanium layer and the intrinsic strain germanium / germanium-silicon multi-quantum well layer.

The utility model discloses an InAs / GaSb superlattice medium / long wave double-color infrared detector based on an nBn structure, which belongs to the technical field of optoelectronic devices and comprises a GaSb substrate, a non-doped GaSb buffer layer, a 14ML InAs / 7ML GaSb superlattice Si doped layer, a 14ML InAs / 7ML GaSb superlattice unintentional doped layer, a 4ML InAs / 7ML GaSb superlattice unintentional doped layer, a 8ML InAs / 6ML GaSb superlattice unintentional doped layer and a 8ML InAs / 6ML GaSb superlattice Si doped layer which are sequentially arranged from bottom to top. The medium / long wave absorption layers of 14ML InAs / 7ML GaSb superlattices and 8ML InAs / 6ML GaSb superlattices are combined, so that high absorption efficiency and low crosstalk of medium / long wave band response are realized, and low dark current and wide temperature range working capability are realized.

This invention discloses a single-pixel reconfigurable dual-mode phototransistor and its fabrication method, along with a pixel array and image edge extraction method. Different polarities are applied to the single-pixel reconfigurable dual-mode phototransistor. Based on a floating base region photogenerated charge accumulation—barrier modulation—transistor gain—Schottky junction photosensitive coupling mechanism, the same pixel switches between two operating modes. Mode one is a switching mode with low dark current and a high on / off ratio threshold triggering function; mode two is a linear mode with a linear analog response and current gain. Utilizing this dual-mode operating mechanism, a sparse operator image edge extraction method of "first screening, then precise measurement" is implemented, reducing system computation and readout overhead at the device level.

The present application relates to a kind of new near hemispherical probe and its preparation method, the near hemispherical probe can retain the excellent electrical characteristics of three-dimensional spherical structure, the area of collection electrode is small under the same electrode spacing, and the capacitance is low, and charge collection efficiency is almost independent of θ.Hemispherical electrode has good sealing, completely isolates detection sensitive area from substrate, dark current is not affected by wafer thickness, and extremely low noise is conducive to low-energy X-ray or low-energy particle detection.

A deep ultraviolet photodetector based on large-size hexagonal boron nitride single crystals and a preparation method thereof, comprising: a substrate; an adhesive, spin-coated on the upper surface of the substrate; a large-size hexagonal boron nitride single crystal, covering the surface of the substrate spin-coated with the adhesive; and a pair of electrodes, partially covering the upper surface of the large-size hexagonal boron nitride single crystal. The present invention prepares a deep ultraviolet photodetector with high response speed, high switching ratio, and high spectral selectivity in the deep ultraviolet region through large-area, high-quality, and moderately thick large-size hexagonal boron nitride single crystals. The detector has great application prospects in space optical communications, military early warning detection, ozone hole monitoring, and aerospace fields.

The invention relates to the field of photoelectric detectors, in particular to a vertical germanium-silicon avalanche photoelectric detector and a preparation method thereof. The silicon-on-insulator structure sequentially comprises a silicon-on-insulator substrate, an intrinsic silicon layer, an intrinsic germanium layer and a P-type germanium layer from bottom to top, the intrinsic silicon layer comprises an intrinsic multiplication layer; a P-type silicon charge layer is arranged at the top of the upper surface of the intrinsic multiplication layer; the P-type silicon charge layer is provided with a P-type silicon shielding ring layer along the circumferential direction; the aluminum oxide layer coats the upper surface of the silicon-on-insulator substrate, the intrinsic silicon layer, the intrinsic germanium layer and the P-type germanium layer; a spin-coating dielectric layer is arranged on the outer surface of the aluminum oxide layer; first metal electrodes are respectively arranged at two ends of the upper surface of the silicon-on-insulator substrate; according to the invention, the dark current is reduced to nanoampere magnitude, the diffusion effect of doped elements is reduced, the production cost is reduced, and the large-scale array layout of the device is facilitated.

The invention discloses a mesa type PIN photoelectric detector based on epitaxial Ge on Si and a preparation method, and relates to the technical field of semiconductor photoelectric devices. The detector comprises an N-type silicon Si substrate, a mesa structure formed by an intrinsic Ge layer and a P-type heavily-doped Ge layer which are sequentially and epitaxially arranged on the N-type silicon Si substrate, a passivation layer covering a mesa, and a metal electrode respectively connected with the P-type heavily-doped Ge layer and the N-type silicon Si substrate. According to the invention, the size of a germanium active region is greatly reduced by adopting a structure that a thin layer Ge is extended on the Si substrate and mesa isolation is combined, and generation and recombination of carriers are inhibited by cooperation of a Si / Ge heterojunction and side wall passivation, so that the dark current of the device is remarkably reduced. Meanwhile, by accurately controlling the thickness of the intrinsic Ge layer, flexible optimization can be carried out between high responsivity and high bandwidth, and the requirements of different near-infrared application scenes are met.