45 results about "Band bending" patented technology

The embodiment of the invention provides a composite substrate and a preparation method of the composite substrate, relates to the technical field of semiconductor devices, and is used for solving the technical problem of relatively high bonding interface resistance of a composite substrate formed by bonding a 3C-SiC substrate and a 4H-SiC substrate in related technologies. The composite substrate comprises a 3C-SiC layer and a 4H-SiC layer, the 4H-SiC layer comprises a first surface, and the 3C-SiC layer comprises a second surface; the first surface and / or the second surface comprises a high-concentration doped layer with N-type conductivity, and a bonding interface of the 3C-SiC layer and the 4H-SiC layer is a contact surface between the high-concentration doped layer and the second surface, between the high-concentration doped layer and the first surface or between the high-concentration doped layer and the two high-concentration doped layers. The interface energy band is adjusted through the energy band bending effect of the high-concentration doping layer, the barrier width and height of the bonding interface are reduced, electrons penetrate through the barrier through a tunneling mechanism, the migration efficiency of the electrons on the heterojunction interface is improved, and the interface resistance is reduced.

Various embodiments of the present application are directed towards a group III-V device including a rough buffer layer. The rough buffer layer overlies a silicon substrate, a buffer structure overlies the rough buffer layer, and a heterojunction structure overlies the buffer structure. The buffer structure causes band bending and formation of a two-dimensional hole gas (2DHG) in the rough buffer layer. The rough buffer layer includes silicon or some other suitable semiconductor material and, in some embodiments, is doped. A top surface of the rough buffer layer and / or a bottom surface of the rough buffer layer is / are rough to promote carrier scattering along the top and bottom surfaces. The carrier scattering reduces carrier mobility and increases resistance at the 2DHG. The increased resistance increases an overall resistance of the silicon substrate, which reduces substrate loses and increases a power added efficiency (PAE).

The invention discloses a cadmium telluride solar cell and a preparation method thereof. The cadmium telluride solar cell comprises a substrate, a TCO layer, a window layer, a cadmium telluride layer, an aluminum oxide passivation layer, a back contact layer and a back electrode layer which are arranged in sequence. The surface, rich in oxygen atoms, of the aluminum oxide passivation layer can effectively passivate dangling bonds and defect states on the surface of CdTe, so that the open-circuit voltage (Voc) and the fill factor (FF) of the cell are improved; the aluminum oxide passivation layer forms a high conduction band bottom barrier for electrons, so that the electrons can be effectively prevented from moving from CdTe to the back contact direction to improve Voc; and meanwhile, the interface state pinning effect can be reduced, so that better energy band bending can be formed.

This application relates to the field of terahertz emission, specifically providing a low-frequency terahertz emitting device and its fabrication and usage methods. The device includes an excitation material, which is a heterojunction formed by a perovskite layer and a high-resistivity silicon layer. It also includes a first metal layer disposed outside the perovskite layer and a second metal layer disposed outside the high-resistivity silicon layer. During fabrication, a perovskite solution is first spin-coated onto the high-resistivity silicon to form a perovskite layer, and finally, the metal layers are deposited by vapor deposition. During use, a femtosecond laser is incident from one side of the perovskite layer, and a voltage is applied between the first and second metal layers. The applied electric field of this application enhances the interfacial band bending and widens the depletion layer, while simultaneously forming a stable potential gradient in the thickness direction. This makes the transient current change smoother, increases the time constant, and reduces the rate of change of the transient current over time, thereby increasing the proportion of the low-frequency terahertz component and achieving enhanced low-frequency radiation.

The present application relates to the technical fields of electric heat tracing band detection, and specifically relates to a kind of electric heat tracing band bending performance detection device, including workbench, two bending tables are symmetrically arranged on slide rail, fixed part is arranged in the bending table, limit post is slidably connected on the bending table, the outer wall of the fixed part is fixedly connected with second sliding plate, the outer wall of the limit post is fixedly connected with first sliding plate, the fixed part is slidably connected with first sliding plate, two drive mechanisms are respectively arranged in the position of fixed part below bending table, moving mechanism is arranged between two slide rails, two drive mechanisms are respectively symmetrically arranged on moving mechanism.The present application can realize the effect of fixing and bending of different specifications of electric heat tracing band, and also can realize automatic and repeated bending of electric heat tracing band through drive mechanism, and the bending radius and angle of electric heat tracing band can be changed through moving mechanism, so as to realize the detection of electric heat tracing band under multiple angles.

Disclosed herein are an LED system having color adjustability in response to a change in drive current density and a method of operating the same. In one example, the system includes a patterned dielectric layer, a multiple quantum well (MQW) region, an electron blocking layer (EBL), and a p-type GaN layer. The EBL is deposited on the MQW region and is structured such that the injection of holes into the MQW region is plane-specific. Plane-specific hole injection results in target color emission associated with band bending levels. A p-type GaN layer is deposited over the EBL and doped into a hole source. For shorter wavelength emission, p-GaN is designed such that sufficient holes are supplied to the lower layer of the MQW region. This selective hole injection along the direction of each crystal plane, in combination with controlled indium concentration and sufficient hole supply in the MQW region, achieves smooth color adjustability.

The utility model discloses a bending side-pushing forming discharging structure which comprises a machine cabinet and a discharging port, a feeding baffle is connected to the front end of the machine cabinet, two sets of sliding rails are arranged in the machine cabinet and located on one side of the feeding baffle, a sliding base is connected to the sliding rails in a sliding mode, a first air cylinder is arranged in the machine cabinet, and a piston rod of the first air cylinder is connected with the sliding base through a fixing plate. A plurality of lifting rods are connected to the bottom of the lifting plate, the other ends of the lifting rods movably penetrate through the sliding seat, a toothed plate is connected to the lifting rods, a tooth roller is rotationally connected to the interior of the sliding seat through a bearing, and the toothed plate is meshed with the tooth roller; by means of the automatic assemblies such as the first air cylinder and the second air cylinder, automatic discharging after metal material strips are bent and formed is achieved, manual material receiving and discharging are not needed, compared with a traditional manual discharging mode, the discharging time is greatly shortened, and efficiency reduction caused by manual fatigue is avoided.

The invention discloses a GaN-based P-type ohmic contact structure based on a silicon nitride and magnesium nitride composite structure and a preparation method of the GaN-based P-type ohmic contact structure, and the ohmic contact structure is arranged on a P-type GaN layer and comprises a SiN / MgN composite structure. The SiN / MgN composite structure is formed by stacking SiN layers and MgN layers of 1 to 3 cycles; wherein the thickness of the SiN layer is 1-2 nm, and the thickness of the MgN layer is 2-4 nm; the Si doping concentration of the SiN layer is 1 * 10 < 17 >-6 * 10 < 17 > cm <-3 >, and the Mg doping concentration of the MgN layer is 5 * 10 < 19 >-3 * 10 < 21 > cm <-3 >. The preparation method provided by the invention comprises the step of growing the composite structure under the conditions of 750-900 DEG C and 200-500 Torr. The high work function of MgN, the energy band bending of the SiN / PGaN interface and the tunneling effect formed by Mg diffusion are utilized to synergistically reduce the P-type ohmic contact resistance, and the beneficial effects of reducing the voltage of the device and improving the brightness and the lighting effect are achieved.

According to the gallium nitride-based semiconductor laser with the gradually-changed hole mobility waveguide layer, a fitting curve of In ion strength distribution or In atom concentration distribution, a fitting curve of valence band effective state density distribution and a fitting curve of hole mobility distribution of an upper waveguide layer and a lower waveguide layer which are tested by SIMS all meet any function distribution of ExpGrow1, ExpGrow2, Lorentz and Bradley; energy band degeneracy is improved, ionization impurities, polarization charges and energy band bending restriction are reduced, coupling of a heavy hole band and a light hole band with an SO band is regulated and controlled, valence band effective state density is improved, population inversion and laser gain are enhanced, hole mobility distribution of a waveguide layer is controlled to be in splayed distribution, interface scattering and ionization impurity scattering are inhibited, and the performance of the laser is improved. The hole mobility and the thermal stability are improved, the hole transport efficiency is enhanced, the hole leakage is reduced, and the slope efficiency, the optical power, the aging life and the temperature quenching ratio of the laser are improved.

An LED system with color variability in response to variations in the drive current density is disclosed. In one example, the system comprises a structured dielectric layer, a multi-quantum-well (MQW) region, an electron-blocking layer (EBL), and a p-doped GaN layer. The EBL is deposited on the MQW region and is structured such that hole injection into the MQW region is plane-specific. Plane-specific hole injection leads to targeted color emission, which is tied to the bandbending level. The p-doped GaN layer is deposited above the EBL and is doped as a hole source. For shorter-wavelength emissions, the p-GaN is designed to provide sufficient hole supply to the lower layers of the MQW region.This selective injection of holes towards different crystal planes, together with a controlled indium concentration in the MQW region and a sufficient supply of holes, enables stepless color variation.

Disclosed herein is an LED system and method that emits within a red wavelength in response to a drive current density change. In one example, the system includes a patterned dielectric layer, a plurality of quantum well (MQW) regions, an electron blocking layer (EBL), and a p-type GaN layer. The EBL is deposited on the MQW region and is structured such that the injection of holes into the MQW region is plane-specific. Plane-specific hole injection results in target color emission associated with band bending levels. A p-type GaN layer is deposited over the EBL and doped into a hole source. For shorter wavelength emission, p-GaN is designed such that sufficient holes are supplied to the lower layer of the MQW region. This selective hole injection along the direction of each crystal plane, in combination with controlled indium concentration and sufficient hole supply in the MQW region, can achieve smooth color adjustability.

The invention provides a bundling device and bundling equipment, and belongs to the technical field of automatic bundling. The bundling device comprises a belt bending assembly, a first driving piece, a guide column and a reversing plate. The band bending assembly comprises a mounting plate, a band bending plate and a steering protruding block, the mounting plate is provided with a containing groove and an opening so as to contain part of the structure of the binding band, the band bending plate is rotationally connected with the mounting plate and used for bending the toothed band strip, and the steering protruding block and the band bending plate are relatively static. The first driving piece is configured to drive the belt bending assembly to move. The surface, abutting against the steering protruding block, of the guide column is a guide face, and the guide face can guide the steering protruding block to rotate so that the belt bending plate can rotate to bend the toothed belt strip. The reversing plate is provided with a reversing groove, the reversing groove is provided with an inlet and an outlet which are in the same direction, and the bent toothed belt strip can face the inlet so that the bent toothed belt strip can be reversed in the reversing groove, penetrate out of the outlet and penetrate through the binding opening, and the binding belt can bind a to-be-bound piece arranged on the reversing plate. According to the bundling device, the bundling efficiency of the ribbon can be improved.

The present invention belongs to the field of organic semiconductor technology, and specifically provides a multiplication-type organic photodetector based on high-temperature induced interface traps, which is used to solve the problems of low response speed, high operating voltage and complex process of existing multiplication-type organic photodetectors. The present invention comprises: a substrate, a transparent conductive cathode, a cathode modification layer, a photosensitive layer, an anode modification layer and an anode layer stacked in sequence from bottom to top; wherein the photosensitive layer is subjected to high-temperature thermal annealing treatment, so that a granular defect morphology is formed on its upper surface as an interface trap, so that photogenerated carriers are trapped and accumulated at the interface, thereby inducing interface energy band bending and tunneling injection of external circuit charges, generating a photomultiplier effect, and thus significantly improving the external quantum efficiency of the device and enhancing the detection performance of the detector; and the defect state morphology can be finely controlled by the thermal annealing temperature, annealing time and thickness of the photosensitive layer; in addition, the preparation process of the present invention is simple, the cost is low, and it is easy to realize industrial production.

The invention discloses a high passivation method of a crystalline silicon bottom cell, the crystalline silicon bottom cell and a laminated solar cell thereof. The high passivation method comprises the following steps: providing a crystalline silicon substrate; carrying out thermal oxidation by adopting LPCVD (Low Pressure Chemical Vapor Deposition), and preparing a tunneling silicon oxide layer on the crystalline silicon substrate; sequentially carrying out first intrinsic silicon layer deposition, phosphorus-rich layer or boron-rich layer deposition and second intrinsic silicon layer deposition on the tunneling silicon oxide layer; performing high-temperature annealing diffusion in a nitrogen environment in high-temperature diffusion equipment to obtain a polycrystalline silicon layer with high doping concentration; the surface is properly oxidized through post-thermal oxidation, and a phosphorosilicate glass layer or a borosilicate glass layer is formed on the polycrystalline silicon layer. According to the method, the doping concentration of doped atoms in the polycrystalline silicon layer is effectively improved, the energy band bending degree between the crystalline silicon substrate and the polycrystalline silicon layer is enhanced, the field effect passivation strength and the passivation level of the crystalline silicon bottom battery are further improved, and finally the open-circuit voltage of the crystalline silicon bottom battery and the contribution to the open-circuit voltage of the laminated battery are improved.

The application belongs to the field of nanomaterial piezoelectric photocatalysis, and relates to a preparation method of a defect state tungsten oxide coated bismuth ferrite nanomaterial (WO 3‑x / BiFeO3) and application of the nanomaterial in the field of piezoelectric photocatalysis. WO 3‑x / BiFeO3 is synthesized by a hydrothermal method, WO 3‑x The application has excellent light absorption capacity in the visible to near infrared region, and enhances effective utilization of sunlight by the composite material. BiFeO3 can form a piezoelectric field under ultrasonic action, provides driving force for photo-induced charges, suppresses photo-induced electron-hole recombination, and can bend a band and narrow a band gap, which is helpful to piezoelectric photocatalytic decomposition of organic pollutants and decomposition of water to produce hydrogen. The piezoelectric photocatalytic degradation efficiency of methylene blue by WO 3‑x / BiFeO3 is 3.29 times that of BiFeO3, the piezoelectric photocatalytic hydrogen production amount is 4.86 times that of BiFeO3, and the piezoelectric photocatalytic performance is significantly improved. The application describes a preparation method of a defect state tungsten oxide coated bismuth ferrite nanomaterial and application of the nanomaterial in piezoelectric photocatalytic degradation of organic pollutants and decomposition of water to produce hydrogen, and the preparation process flow is simple and has wide application prospect.

Various embodiments of the present application are directed towards a group III-V device including a rough buffer layer. The rough buffer layer overlies a silicon substrate, a buffer structure overlies the rough buffer layer, and a heterojunction structure overlies the buffer structure. The buffer structure causes band bending and formation of a two-dimensional hole gas (2DHG) in the rough buffer layer. The rough buffer layer includes silicon or some other suitable semiconductor material and, in some embodiments, is doped. A top surface of the rough buffer layer and / or a bottom surface of the rough buffer layer is / are rough to promote carrier scattering along the top and bottom surfaces. The carrier scattering reduces carrier mobility and increases resistance at the 2DHG. The increased resistance increases an overall resistance of the silicon substrate, which reduces substrate loses and increases a power added efficiency (PAE).

According to the precise terminal material strip bending forming system, a female die is arranged on a lower die plate of a terminal material strip cutting die, and a terminal material strip of a coil changing head with a rated step length and a terminal material strip of a bending die tail are correspondingly cut into a terminal material strip head and a terminal material strip tail through a left cutting positioning needle set and a right cutting positioning needle set which are arranged on the female die; a copper welding block between a left bakelite fixing block and a right bakelite fixing block of the terminal material strip welding mechanism is provided with a left welding positioning pin group and a right welding positioning pin group, and the distance between the left welding positioning pin group and the right welding positioning pin group is equal to the distance between the left cutting positioning pin group and the right cutting positioning pin group. The left cover plate and the right cover plate are correspondingly arranged on the terminal material belt at the reel changing head and the terminal material belt at the tail of the bending die in a covering manner respectively and are correspondingly arranged above the left bakelite fixing block and the right bakelite fixing block; and the head part of the welding terminal material belt and the tail part of the welding terminal material belt are formed by stamping a whole material belt from the bending forming die. According to the system, the loss ratio of the head and tail materials of each roll of terminal material belt is reduced, and the terminal material belt can be prevented from being deformed, so that the bending process is ensured to be smoothly carried out.

To provide an LED system having color adjustability in response to changes in drive current density.SOLUTION: In one example, the system includes a patterned dielectric layer, a multiple quantum well (MQW) region, an electron blocking layer (EBL), and a p-type GaN layer. The EBL is deposited on the MQW region and is structured such that injection of holes into the MQW region is planar specific. The planar intrinsic hole injection leads to a target color emission associated with the level of band bending. A p-type GaN layer is deposited over the EBL and is doped to be a source of holes. For shorter wavelength emission, the p-GaN is engineered to provide sufficient holes to the underlying layers of the MQW region. This selective hole injection in the direction of the various crystal planes, together with a managed indium concentration in the MQW region and a sufficient supply of holes, enables smooth color tunability.SELECTED DRAWING: Figure 1A

The invention provides a photovoltaic-multiplication dual-mode photoelectric detector based on adjustable bias polarity and a preparation method thereof, the photovoltaic-multiplication dual-mode photoelectric detector adopts a multi-layer structure design, and specifically comprises a transparent substrate, a first conductive electrode layer, an electron transport layer, a photosensitive active layer, a hole transport layer and a second conductive electrode layer from bottom to top in sequence; the photosensitive active layer is a heterojunction formed by an organic polymer donor and a fullerene acceptor. Under forward bias voltage, the electron trap captures photo-induced electrons and triggers energy band bending, so that holes can be tunneled and injected from an external circuit, and a high-gain photomultiplication type detection mode is realized; under reverse bias voltage, photo-generated holes and electrons in the heterojunction are respectively collected by the hole transport layer and the electron transport layer, and a photovoltaic detection mode is realized. Through the cooperative detection capability of the double working modes, the detector has the advantages of a photovoltaic mechanism and a multiplication mechanism, has tunable dark current and photoelectric gain, and can ensure the flexible detection of the photoelectric detector on strong light or weak light.

The invention discloses an electric tracing band bending performance test device, which belongs to the technical field of electric tracing band detection, and comprises a winding part, a fixing piece, a machine table, a clamping structure and a locking mechanism. A first winding fixed shaft and a second winding fixed shaft are arranged on the machine table, the winding fixed shaft comprises a plurality of different-diameter shaft sections, the adjacent different-diameter shaft sections are connected through variable-diameter cone sections, bypasses are formed in the surface of the winding fixed shaft, and the distance between the bypasses formed in the surfaces of the variable-diameter cone sections gradually changes in the axial direction of the winding fixed shaft. According to the invention, dynamic winding and covering of the electric tracing band are realized through the plurality of winding and fixing shafts, the plurality of reducing shaft sections and the reducing cone sections between the adjacent reducing shaft sections in cooperation with the bypasses of which the surface spacing distribution is different or the spacing is gradually changed. And the variable-diameter cone section around the fixed shaft is matched with the detour distribution with gradually-changed spacing, so that the bending radius and the final bending angle of the electric tracing band can be steplessly adjusted.

The invention relates to the field of semiconductors, and discloses an epitaxial structure and a deep ultraviolet photoelectric device based on an AlInN hole injection tunnel junction layer, and the epitaxial structure comprises a substrate, and a buffer layer, a superlattice layer, an n-type semiconductor layer, a multi-quantum well layer and a tunnel junction layer which are located on the upper surface of the substrate and are sequentially stacked in the direction away from the substrate, the tunnel junction layer comprises a heavily doped p-type AlInN hole injection layer, an intrinsic polarization AlGaN layer and a heavily doped n-type AlInN layer. The layer material of the hole injection layer is AlInN, under the same forbidden bandwidth, the AlInN material has larger lattice constant, intrinsic polarization and piezoelectric polarization than the AlGaN material, polarization surface charges with higher density can be generated at the interface of the AlInN material and the intrinsic polarization AlGaN layer, the electric field intensity of a tunnel junction space charge region is increased, the energy band bending of the tunnel junction space charge region is enhanced, and the hole injection efficiency is improved. Carrier tunneling is promoted, and the electrical performance and the wall insertion efficiency of the epitaxial structure are improved.

The application discloses a pH-responsive bismuth-based nanodrug and a preparation method and pharmaceutical application thereof. The nanodrug is hyaluronic acid modified cuprous oxide / iodine bismuth oxide heterojunction nanoparticles (Cu2O@BiOI-HA), the cuprous oxide has a double-layer hollow mesoporous structure, the iodine bismuth oxide is loaded on the surface of the cuprous oxide in a nanolayer to form a heterojunction, the particle size is 200-700 nm, and the band gap is 1.46-1.49 eV. The nanodrug produces active oxygen by promoting the separation of electron-hole pairs through band bending under the excitation of ultrasound, releases Cu + ions under acidic conditions, generates hydroxyl radicals by means of a Fenton-like reaction, realizes the synergistic treatment of sonodynamic and chemical dynamics, and simultaneously, the Cu + ions induce copper death, the active oxygen activates the pyroptosis pathway, the multimodal cell death synergistically triggers immunogenic cell death, and the anti-tumor immune response is activated. The application establishes a structure-activity relationship between synthesis parameters and sonodynamic performance, and has application value in the treatment of breast cancer.

To provide an LED system having color adjustability in response to changes in drive current density.SOLUTION: In one example, the system includes a patterned dielectric layer, a multiple quantum well (MQW) region, an electron blocking layer (EBL), and a p-type GaN layer. The EBL is deposited on the MQW region and is structured such that injection of holes into the MQW region is planar specific. The planar intrinsic hole injection leads to a target color emission associated with the level of band bending. A p-type GaN layer is deposited over the EBL and is doped to be a source of holes. For shorter wavelength emission, the p-GaN is engineered to provide sufficient holes to the underlying layers of the MQW region. This selective hole injection in the direction of the various crystal planes, together with a managed indium concentration in the MQW region and a sufficient supply of holes, enables smooth color tunability.SELECTED DRAWING: Figure 1A

An LED system having color tunability in response to variations in driving current density is disclosed. In one example, the system includes a patterned dielectric layer, multiple quantum well (MQW) region, electron blocking layer (EBL), and p-type GaN layer. The EBL is deposited on the MQW region and structured such that the injection of holes into the MQW region is plane-specific. Plane-specific hole injection leads to targeted color emission tied to the level of band bending. The p-type GaN layer is deposited above the EBL and is doped to be a source of holes. For shorter wavelength emission, the p-GaN is designed such that there is adequate hole supply to lower layers of the MQW region. This selective injection of holes in the direction of various crystal planes, together with managed Indium concentration in the MQW region and an adequate supply of holes, enables smooth color tunability.

The application belongs to the method for improving the photoelectric conversion efficiency and stability of a device, and particularly relates to a method for reducing the defect density and surface potential of an organic-inorganic hybrid perovskite film by using a N-heterocyclic ring passivation agent through π-Pb 2+ The application relates to a method for reducing defect density and surface potential of an organic-inorganic hybrid perovskite film and enabling band bending of a perovskite material and improving charge extraction efficiency. An additive is added in a reverse solvent during preparation of an organic-inorganic hybrid perovskite film, and is attached and gathered on the surface of the formed organic-inorganic hybrid perovskite film. The application effectively passivates defects of the perovskite film by introducing a N-heterocyclic ring organic small molecule into the perovskite film, and improves the stability of the film and a corresponding device. The material used is low in cost and easy to realize in a process.

The application provides a porous bismuth vanadate nanorod loaded sheet-shaped cobalt-doped graphite phase carbon nitride photoanode catalyst, a preparation method thereof and application thereof in the field of photoelectrocatalytic water splitting to produce hydrogen. A spin-coating and annealing process is used to tightly load Co:g-C3N4 nanosheets on the surface of porous BiVO4 nanorods, and the energy band structure of the Co:g-C3N4 nanosheet is regulated by adjusting the doping ratio of Co, and then a Co:g-C3N4 / BiVO4 heterojunction photoanode with good energy band matching is constructed. Among them, the ultrathin sheet-shaped Co:g-C3N4 has a more negative conduction band potential and a wider light absorption range than BiVO4, which is conducive to expanding the light response interval; and the energy band bending on the BiVO4 side helps to promote the directional transmission of photo-generated electrons to the photocathode. Based on the synergistic effect of the two materials, the heterojunction structure can shorten the carrier transmission path, promote the effective separation of photo-generated electron-hole pairs, and thus improve the photoelectrocatalytic water splitting to produce hydrogen performance. In addition, the preparation process is simple and clear in operation, and has potential for large-scale application.

This invention relates to the field of semiconductor laser technology, specifically to an epitaxial structure of a GaN-based blue laser and its fabrication method. The structure includes a substrate on which an N-type GaN layer, an N-type lower confinement layer, an N-type lower waveguide layer, an active region, an upper waveguide layer, a U-type capping layer, a P-type electron blocking layer, a P-type upper confinement layer, and a P-type contact layer are sequentially stacked. The P-type electron blocking layer comprises a sequentially stacked AlN sublayer and a P-type InAlGaN sublayer. The P-type electron blocking layer of this invention utilizes the piezoelectric polarization and spontaneous polarization of the P-type InAlGaN sublayer to induce a large band bend at the heterojunction, placing the P-type dopant acceptor energy level below the Fermi level, thereby increasing the ionization rate of the P-type dopant acceptor at the cross-section and thus increasing the hole concentration. Furthermore, the use of a high-Al composition AlN sublayer near the active region can raise the energy band, confine electron overflow in the active region, and reduce non-radiative recombination of electrons and holes in the non-recombination region, thereby improving the luminous efficiency of the device.

The invention provides a gradient-doped electron transport layer, a preparation method thereof and a perovskite cell, and belongs to the technical field of solar cells, and the preparation method comprises the following steps: dispersing a tin salt in a solvent to obtain an undoped electron transport layer solution; dispersing tin salt and a doping agent in a solvent to obtain a doped electron transport layer solution; the dopant comprises at least one of antimony salt, aluminum salt, zinc salt and niobium salt; and sequentially spraying the undoped electron transport layer solution and the doped electron transport layer solution on the surface of a conductive substrate, annealing at 90-110 DEG C for 5-30 minutes, and then annealing at 150-200 DEG C for 5-30 minutes to obtain the gradient doped electron transport layer. According to the invention, energy band bending of the electronic layer can be realized, energy band matching between the electronic layer and perovskite can be optimized and adjusted, extraction and transmission of carriers at an interface can be promoted, non-radiative recombination of photon-generated carriers can be inhibited, and the problem of perovskite degradation caused by local overheating of the interface due to recombination of the photon-generated carriers can be avoided.

The invention relates to the technical field of material mechanical property testing, in particular to a broadband bending modulus testing device and method based on piezoelectric stack driving, and the device comprises a force excitation unit, a mechanical calibration elastic element, a displacement measurement unit, a to-be-tested object clamping unit and a high-speed imaging module; the broadband bending modulus testing device based on piezoelectric stack driving solves the problems that the existing mechanical testing technology mainly focuses on static or low-frequency conditions, such as nanoindentation and AFM methods, cannot effectively apply high-frequency transverse shear force, and cannot capture micron-sized high-speed bending deformation.

The embodiment of the application provides a composite substrate and a preparation method of the composite substrate, relates to the technical field of semiconductor devices, and is used for solving the technical problem of a large bonding interface resistance of a composite substrate formed by bonding a 3C-SiC substrate and a 4H-SiC substrate in the related art; the composite substrate comprises a 3C-SiC layer and a 4H-SiC layer, the 4H-SiC layer comprises a first surface, and the 3C-SiC layer comprises a second surface; the first surface and / or the second surface comprises a high-concentration doped layer with N-type conductivity, and a bonding interface of the 3C-SiC layer and the 4H-SiC layer is a contact surface of the high-concentration doped layer and the second surface, the high-concentration doped layer and the first surface or the two high-concentration doped layers. The band bending effect of the high-concentration doped layer is used to adjust the interface band, the width and height of the potential barrier of the bonding interface are reduced, electrons pass through the potential barrier through a tunneling mechanism, the migration efficiency of the electrons at the heterojunction interface is improved, and the interface resistance is reduced.