10 results about "Double heterostructure" patented technology

A method for forming a semiconductor structure includes the following operations. A substrate is provided. The substrate includes double heterostructures arrayed along a first direction and a second direction. Each of the double heterostructures includes a first semiconductor layer, a second semiconductor layer and another first semiconductor layer sequentially arranged along the first direction. A forbidden band gap of the first semiconductor layer is different from a forbidden band gap of the second semiconductor layer. The first direction is perpendicular to the second direction, and both the first direction and the second direction are parallel to a direction of a plane where the substrate is located. A double gate structure is formed on sidewalls of each of the double heterostructures along the first direction.

The invention provides a high-plasticity Mg-Sn-Zn-Zr alloy and a preparation method thereof, and belongs to the technical field of magnesium alloy deformation processing. The preparation method of the high-plasticity Mg-Sn-Zn-Zr alloy, provided by the invention, comprises the following steps: directly carrying out positive extrusion deformation treatment on an as-cast alloy, and then carrying out differential-temperature equal-channel angular extrusion deformation treatment to obtain the high-plasticity Mg-Sn-Zn-Zr alloy, during the differential temperature equal channel angular pressing deformation treatment, the temperature of the alloy is 100-150 DEG C, and the temperature of the mold is 300-350 DEG C. According to the method, during differential-temperature equal-channel angular pressing deformation treatment, the alloy and the mold are both heated, so that after differential-temperature equal-channel angular pressing deformation treatment is carried out, a double-heterostructure in which coarse and fine crystal double-peak crystal grains and a second phase of a harmonic-like structure coexist is formed, and the alloy performance is remarkably improved; and the ductility of the high-plasticity Mg-Sn-Zn-Zr alloy is as high as 37.9%.

The application discloses a preparation method of a copper alloy with a double heterostructure and belongs to the technical field of material preparation. The method comprises the following steps: firstly, a copper plate and an aluminum plate are subjected to accumulative roll bonding to obtain a Cu / Al multilayer composite plate; and finally, the obtained sample is subjected to surface grinding and polishing, and surface nanocrystallization treatment is carried out at room temperature for 2 min. It is found for the first time that after the accumulative roll bonding, annealing is carried out, a hetero-layer structure is formed, and the traditional surface nanocrystallization structure is superposed, so that a double heterostructure is formed, and the double heterostructure with matched yield strength and plasticity is obtained.

The invention discloses a titanium alloy diffusion bonding joint with a double-heterostructure, and the grain size of the bonding joint is in'fine-coarse-fine 'gradient distribution in the direction from a weld interface to a matrix. The invention further discloses a preparation method and application of the titanium alloy diffusion bonding joint with the double-heterostructure. According to the method, a gradient nanocrystalline layer and a high-density dislocation structure are formed on the to-be-connected surface through the composite surface treatment process of multi-pass high-energy shot blasting and ultrasonic surface rolling, a rapid channel is provided for atomic diffusion at low temperature, high-quality diffusion connection of titanium alloy can be achieved at the low temperature of 700-800 DEG C, and the shear strength of an obtained connection joint is larger than or equal to 600 MPa; and equipment used in the technological process is conventional industrial equipment and can be directly applied to an existing production line conveniently, large-scale equipment transformation is not needed, the investment cost is low, and the implementation efficiency is high.

The invention relates to a chemical / structural double-heterogeneous high-strength plastic low alloy Qamp based on a flash thermal excitation effect. A P steel plate and a preparation method belong to the field of development of advanced high-strength steel for automobiles. The steel plate comprises the following chemical components: Fe, C, Si, Mn, V, P, S and inevitable impurities, and the thickness of the steel plate is 1.0-1.5 mm. The preparation method comprises the following steps: 1) alloy smelting, casting and forging; 2) hot rolling; 3) cold rolling; and 4) flash thermal excitation annealing treatment. The yield strength of the steel plate ranges from 660 MPa to 920 MPa, the tensile strength ranges from 1100 MPa to 1350 MPa, the yield ratio ranges from 0.5 to 0.7, the uniform elongation ranges from 8.0% to 12.0%, the percentage elongation after fracture ranges from 13.0% to 16.0%, and the product of strength and elongation ranges from 16000 MPa% to 21000 MPa%. The steel plate disclosed by the invention has a body-centered cubic / face-centered cubic double heterostructure consisting of non-recrystallized ferrite, recrystallized ferrite, island-shaped martensite, lath martensite, blocky retained austenite and film-shaped retained austenite, and obvious chemical component heterogeneity exists in the retained austenite. According to the preparation method disclosed by the invention, cold rolling Qamp is remarkably shortened; the annealing time of the P steel is long, and the method is used for developing a low-cost, high-performance and low-alloy heterostructure Qamp; a novel method is provided for P steel.

The invention relates to a device for emitting laser beams, comprising a double heterostructure (1) which comprises three semiconductor layers (2, 3, 4) grown one on top of the other and the outer semiconductor layers (3, 4) of which have doping types which differ from each other. In order to provide such a device which can be obtained using conventional production methods and makes it possible to generate laser light even at typical ambient temperatures of 0-55°C, it is proposed that an inner semiconductor layer (2) forming a type II p-n or p-i-n junction is arranged between the outer semiconductor layers (3, 4) of the double heterostructure (1) forming a laser diode, the voltage across the outer semiconductor layers (3, 4) being such that the difference between the two Fermi energies, which relate to the band states and describe the population of the conduction band states with electrons and / or the population of the valence band states with holes, in the inner semiconductor layer (2) corresponds at least to the band gap there.

The invention discloses a carbon-supported molybdenum-based compound and layered double hydroxide co-modified photocatalyst and a preparation method thereof, and belongs to the technical field of hydrogen production by photocatalytic decomposition of water. According to the photocatalyst, a carbon-loaded molybdenum-based compound is a thin-wall large / mesoporous hollow nitrogen-doped carbon tube HNC-loaded Mo2C / MoO2 compound marked as Mo-C / O, and the size of the Mo2C / MoO2 compound is limited by using Mo-C / O as a cocatalyst; the layered double hydroxide is a cage-shaped NiCo-LDH (layered double hydroxide) compound, and ZnCdS is co-modified by Mo2C / MoO2 and NiCo-LDH (layered double hydroxide); the ZnCdS and the Mo2C / MoO2 form a Schottky junction, the NiCo-LDH and the ZnCdS form a type II heterojunction, and a cascade electron transmission channel is formed among the Mo2C / MoO2, the ZnCdS and the NiCo-LDH. Through the synergistic effect of the double heterostructures, the light response range can be widened, the separation efficiency of photon-generated carriers can be further enhanced, the driving force of charge migration is improved, the directed migration of electrons is promoted, the reaction kinetics is improved, and the photocatalytic hydrogen evolution performance is further improved.

The present invention discloses a dual-graded Ni-Cr-V-Al medium entropy alloy and a preparation method thereof. The microstructure of the Ni-Cr-V-Al medium entropy alloy includes a grain heterogeneous structure and a precipitate heterogeneous structure; the elemental percentage composition expression is: M d Al p , where 80% ≤ d < 100%, 0 < p ≤ 20%, and d + p = 100%; M includes the following elemental percentage composition: Ni ≤ 80%, Cr ≤ 60%, V ≤ 60%, and Ni, Cr, and V are all not 0%, and the elemental percentage contents of Cr and V are both less than the elemental percentage content of Ni. The medium entropy alloy obtains a dual heterogeneous structure by micro-alloying with Al element to hinder recrystallization and simultaneously promote hierarchical precipitation, so as to achieve the synergistic strengthening effect of heterogeneous strengthening, precipitation strengthening, and dislocation strengthening, and has high yield strength and high tensile strength while maintaining good plasticity.

The invention relates to the technical field of nickel-based high-temperature alloy treatment, in particular to a method for improving the high-temperature toughness of a GH4099 alloy. According to the method, the GH4099 alloy in the solid solution state is subjected to ultrasonic rolling to form a rolling deformation layer, and then aging treatment is carried out; the aging treatment temperature ranges from 780 DEG C to 820 DEG C, a double-heterostructure (a gradient heterostructure from the surface layer to the core part and a heterostructure of particle precipitation and no particle precipitation isometric crystals in the surface layer) can be constructed in the GH4099 alloy, meanwhile, the high-temperature strength and toughness of the GH4099 alloy are improved, and the strength-plasticity inversion relation of a traditional gradient material is overcome.

The application discloses a high-stability and long-cycle-life lithium ion battery negative electrode material, which comprises a multilayer Ti3C2T x skeleton, Ti3C2T x skeleton combined Ti3C2T x @TiO2 heterostructure, and Ti3C2T x skeleton combined Ti3C2T x @La2O3 heterostructure. The application integrates the double heterostructures of Ti3C2Tx@TiO2 and Ti3C2Tx@La2O3 in the same electrode, so that the electrode material has the advantages of high conductivity, high capacity and high stability, meanwhile, the double heterostructures effectively improve the rate performance and overall stability of lithium ions, so that the battery can maintain good performance under different current densities.