214 results about "Topological insulator" patented technology

A Topological INsulator-based field-effect transistor (TINFET) is disclosed. The TINFET includes a first and second gate dielectric layers separated by a topological insulator (TI) layer. A first gate contact is connected to the first gate dielectric layer on the surface that is opposite the TI layer. A second gate contact may be connected to the second gate dielectric layer on the surface that is opposite the TI layer. A first TI surface contact is connected to one surface of the TI layer, and a second TI surface contact is connected to the second surface of the TI layer.

The invention discloses a flexible transparent conductive material of a topological insulator and a preparation method and application of the flexible transparent conductive material of the topological insulator. The preparation method of the flexible transparent conductive material of the topological insulator includes the steps of patterning or functionally modifying a substrate, placing the topological insulator in the middle of the gas flow direction, placing the substrate obtained in the step 1 under the gas flow direction, introducing carrier gas into a reactor for deposition, stopping introducing the carrier gas after the deposition is completed, cooling the substrate to the room temperature and finally obtaining the topological insulator material on the surface of the substrate. The flexible transparent conductive thin film or nano-material obtained with the method has high light transmission performance in a wide wavelength range, particularly in a near infrared region. Besides, a stable conductive channel can be provided by utilizing the special metal surface state of the topological insulator, so that the flexible transparent conductive material has high conductivity, excellent disturbance rejection performance and mechanical properties. The novel flexible transparent photoelectric element can be used in the fields of photoelectronics, nanoelectronics and the like.

The embodiment of the invention provides an OLED (Organic Light Emitting Diode) display device and a manufacturing method thereof as well as a display device, relates to the technical field of display, and solves the problems that the transmission resistance of metal electrodes is high, the voltage drop is larger and the display brightness is non-uniform in the conventional OLED display device. The OLED display device comprises a thin film transistor, a first electrode, a second electrode and an organic function layer positioned between the first electrode and the second electrode, wherein the thin film transistor comprises a grid electrode, a source electrode and a drain electrode; the first electrode is electrically connected with the drain electrode; the display device further comprises a first auxiliary electrode formed by a topological insulator; the first auxiliary electrode is electrically connected with the second electrode and provides an electrical signal for the second electrode; the first electrode and the second electrode are respectively an anode and a cathode.

A topological insulator is grown on an IC wafer in a vacuum chamber as a thin film interconnect between two circuits in the IC communicating with each other. As the TI is being grown, magnetic doping of the various TI sub-layers is varied to create different edge states in the stack of sub-layers. The sub-edges conduct in parallel with virtually zero power dissipation. Conventional metal electrodes are formed on the IC wafer that electrically contact the four corners of the TI layer (including the side edges) to electrically connect a first circuit to a second circuit via the TI interconnect. The TI interconnect thus forms two independent conducting paths between the two circuits, with each path being formed of a plurality of sub-edges. This allows bi-direction communications without collisions. Since each electrode contacts many sub-edges in parallel, the overall contact resistance is extremely low.

The invention relates to a topological insulator structure which comprises an insulating substrate and a magnetic doped topological insulator quantum well film arranged on the surface of the insulating substrate. The magnetic doped topological insulator quantum well film is made of materials shown by a chemical formula Cry (BixSb1-x) 2-yTe3, 0.05 (x (0.3, 0 (y (0.3, 1:1 (x:y (2:1, and the thickness of the magnetic doped topological insulator quantum well film ranges from 3QL to 5QL.

The invention relates to a method for distinguishing a circularly polarized light induced current and a photon dragging current of a topological insulator Sb2Te3. According to the technical scheme, 1064 nm laser is irradiated on a sample after passing through a polarizer and a quarter-wave plate; the quarter-wave plate is rotated to generate periodically-changed polarized light; and a generated light current is fitted to extract the light current generated by circular polarized laser. Light currents generated by the circular polarized laser under different positive and negative incidence angles are measured; and by utilizing a characteristic that even function components of the circularly polarized light current and the photon dragging current have different parity symmetry, and by utilizing different dependence relations of odd function components of the circularly polarized light current and the photon dragging current to the incident angles, the circularly polarized light current and the photon dragging current are distinguished. The method disclosed by the invention is accurate in measurement result, is simple and feasible, is low in cost and is beneficial to the popularizationand application in the future.

The invention discloses a graphene two-dimensional material protective layer-based topological insulator array photoelectric detector and a preparation method and application thereof. The method comprises the following preparation process of (1) growing a topological insulator film which is opposite to a substrate in doping type on the substrate; (2) obtaining a graphene two-dimensional material protective layer/PMMA stack structure by adopting a wetting transfer method and transferring the graphene two-dimensional material protective layer/PMMA stack structure to the topological insulator film; (3) preparing an ITO array electrode through photoetching and magnetron sputtering; and (4) etching away the topological insulator film between array elements of the ITO array electrode and a graphene two-dimensional material through photoetching and reactive ion etching to obtain the photoelectric detector. According to the method, a topological insulator can be effectively prevented from being in direct contact with an organic liquid to be damaged, the method can be compatible with a traditional micro-nano technology, the dimension of the unit detector is shortened, the integration level is improved, a wide spectrum and an ultra-fast photoelectric response are obtained and the method has a wide application prospect.

The present invention provides a two-dimensional material-based quantum dot film for a saturable absorber. The components of the two-dimensional material-based quantum dot film comprise quantum dots, wherein the quantum dots are at least one kind of quantum dots selected from graphene quantum dots, topological insulator quantum dots, transition metal sulfide quantum dots and black phosphorus quantum dots, the size of the quantum dots being smaller than 100 nm; the optical absorption rate of the quantum dot film is larger than that of a quantum dot film made of a conventional two-dimensional material by one order of magnitude; and the quantum dots have a saturable absorption characteristic as the conventional two-dimensional material. The invention also provides a preparation method of the two-dimensional material-based quantum dot film and the application of the two-dimensional material-based quantum dot film. When the quantum dot film is applied to an ultrafast passive mode-locked laser, quantum dots of the different can be selected according to the operating wavelength of the laser, so that the energy band gap of the quantum dots can be consistent with the operating wavelength of the ultrafast mode-locked laser; and due to a quantum confinement effect and an edge effect, the quantum dot material can strongly absorb laser within energy bands, and therefore, the stability of the laser can be improved.

Method and apparatus are provided for improving the thermoelectric figure of merit (zT) for thermoelectric structures and devices based on topological insulators. In one novel aspect, the zT of the TI is increased by optimizing geometric sizes of the TI. In one embodiment, the zT is increased by increasing the length of the TI to be greater than the inelastic mean free path length. In another embodiment, the zT is increased by decrease the width of a 2D TI to be about three times the localized localization width ξ of the boundary state of the TI, or to decrease the thickness of a 3D TI to be about three times of ξ. In one novel aspect of the current invention, methods are provided to increase zT of the TI by substantially maximizing a relative thermoelectric-transport contribution of the boundary state with respect to the bulk states.

The embodiment of the invention provides a self-rotation terahertz transmitter and a terahertz wave generating method. The self-rotation terahertz transmitter at least comprises a femtosecond laser, atopological structure film and a magnetic field generator, wherein pumping light output by the femtosecond laser passes through the topological structure film to generate terahertz waves on the basisof the magnetic field direction of the magnetic field generator; the topological structure film comprises a topological insulation body layer, a ferromagnetic layer and a non-ferromagnetic layer; thetopological insulation body layer, the ferromagnetic layer and the non-ferromagnetic layer are sequentially arranged and attached and form a heterogeneous structure. The transmitter provided by the embodiment of the invention has the advantages that the structure is simple; the transmission principle is simple; the transmission frequency is high; the pulse width is wide; the cost is low.

The invention discloses a carbon-coated class V-VI compound semiconductor nano sheet and a preparation method thereof, and relates to a topological insulator and a thermoelectric material and a preparation method thereof. The method solves the problems that the conventional preparation method for the class V-VI compound topological insulator is complex and cannot be used for preparing bulk materials, the surface of the topological insulator is instable, unsymmetrical and high in roughness and the electric conductivity and the Seebeck coefficient of the topological insulator serving as the thermoelectric material cannot be simultaneously improved. The carbon-coated class V-VI compound semiconductor nano sheet consists of a nano sheet matrix and a carbon layer coated on the surface of the nano sheet matrix. The amorphous carbon-coated class V-VI compound semiconductor nano sheet is prepared through a one-step hydrothermal method; and a grapheme-coated class V-VI compound semiconductor nano sheet is prepared through a two-step hydrothermal method. The surface of the prepared nano sheet is stable, symmetrical and low in roughness, and the electric conductivity and the Seebeck coefficient of the nano sheet can be simultaneously improved. The invention is applied in the field of preparation of topological insulators and thermoelectric materials.

A SOT device includes a bismuth antimony dopant element (BiSbE) alloy layer over a substrate. The BiSbE alloy layer is used as a topological insulator. The BiSbE alloy layer includes bismuth, antimony, AND a dopant element. The dopant element is a non-metallic dopant element, a metallic dopant element, and combinations thereof. Examples of metallic dopant elements include Ni, Co, Fe, CoFe, NiFe, NiCo, NiCu, CoCu, NiAg, CuAg, Cu, Al, Zn, Ag, Ga, In, or combinations thereof. Examples of non-metallic dopant elements include Si, P, Ge, or combinations thereof. The BiSbE alloy layer can include a plurality of BiSb lamellae layers and one or more dopant element lamellae layers. The BiSbE alloy layer has a (012) orientation.

A method for directly electrically generating and detecting spin polarization in topological insulators comprising depositing a first and fourth contact on a layer of Bi₂Se₃ and applying a current between the contacts, which creates a net spin polarization due to spin-momentum locking. A second (comprising ferromagnet/tunnel barrier) and third contact are deposited for detecting the spin polarization. A device for directly electrically generating and detecting the current-generated spin polarization in topological insulators, comprising a first and fourth contact on a layer of Bi₂Se₃ and a second contact comprising a ferromagnet/oxide tunnel barrier contact as a detector, and a third contact comprising nonmagnetic metal as a reference contact, a current to the first and fourth contact to produce a net spin polarization, and the spin polarization manifesting as a voltage between the second (magnetic) and third (reference) contacts.

A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a buffer layer formed over the substrate, and a bismuth antimony (BiSb) layer formed over the buffer layer, the BiSb layer having a (012) orientation. In certain embodiments, the SOT MTJ device is part of a microwave assisted magnetic recording (MAMR) write head. In certain embodiments, the SOT MTJ device is part of a magnetoresistive random access memory (MRAM) device.

The invention discloses a magnetic field measuring meter based on a topological insulator and a magnetic field measuring method. The magnetic field measuring meter comprises a probe and an analyzer, wherein the probe is the flat-plate-shaped topological insulator and the analyzer is a magnetic resistance signal analyzer. The direction of a magnetic field is perpendicular to the surface of the topological insulator; a pair of current electrodes and a pair of magnetic resistance electrodes are arranged on the surface of the topological insulator, and the current electrodes and the magnetic resistance electrodes are in the same direction; the magnetic resistance electrodes are connected with a magnetic resistance signal analyzer. The topological insulator is insensitive to the temperature and can be used within a wide range. The magnetic field measuring meter based on the topological insulator greatly widens magnetic field probing interval of a traditional probe, can well work in a low-temperature region, and is very suitable for laboratory study under extreme conditions like medical nuclear magnetic resonance imaging, military electromagnetic pulse bomb effect measuring and astronautic extremely-low universe temperature and plasma storm high fields; combined with the Hall effect, the magnetic field measuring meter based on the topological insulator can be well applied to traditional fields.

The invention discloses a preparation method of a topological insulator Bi2Se3/FeSe2 alloplasmic structure thin film. The preparation method includes the main steps that a, a FeSe base film is prepared, wherein the FeSe base film is formed on a base sheet through magnetron sputtering; b, FeSe2 annealing phase forming is carried out, wherein the base sheet obtained in the step a and selenium particles are sealed into a vacuum quartz tube with the air pressure smaller than 1*10<-2> Pa, annealing phase forming treatment is carried out, and an FeSe2 thin film is obtained on the base sheet; c, a Bi2Se3 base film is prepared, wherein on the base sheet obtained in the step b, magnetron sputtering is carried out to form a Bi2Se3 film, and then a Bi2Se3/FeSe2 base film is formed on the base sheet; and d, Bi2Se3 annealing phase forming is carried out, wherein the base sheet obtained in the step c and selenium particles are sealed into a vacuum quartz tube with the air pressure small than 1*10<-2> Pa, annealing phase forming treatment is carried out, and the product is obtained. According to the method, the film coating amount is easily controlled, the formed alloplasmic structure thin film is smooth and good in performance. The preparing cost is low.

The invention relates to a material with the quantization abnormal Hall effect and a Hall device formed by the same.In an embodiment, the material with the quantization abnormal Hall effect can comprise a topological insulator substrate, a first element doped into the topological insulator substrate, a second element and a third element.An electronic current carrier is introduced into the first element.The second element and the second element are doped into the topological insulator substrate.A hole type current carrier and magnetism are introduced into each of the second element and the second element.Therefore, a double-magnetism doped topological insulator is formed.

The invention discloses a passive low-power-consumption microwave detection method and a passive low-power-consumption microwave detection device, and a preparation method. The passive low-power-consumption microwave detection method is characterized in that: an antiferromagnetic topological insulator layer is prepared, under microwave energy, spin precession occurs in the antiferromagnetic topological insulator layer to generate a spin current, due to a spin momentum locking feature of a topological surface state, a directional charge flow can be generated spontaneously on the surface if thespin current; and passive low-power-consumption detection of microwave can be achieved through detection of the charge flow by an electrode. The passive low-power-consumption microwave detection method of the invention has the beneficial effects that: multiple antiferromagnetic topological insulator layers can be regarded as being formed by periodic stacking of a double-layer structure consistingof an antiferromagnetic layer and a topological insulator layer, thus microwave detection sensitivity is increased in multiples; the topological surface state shows strong robustness and low-dissipation current transmission characteristic, thereby reducing power consumption of microwave detection; the passive low-power-consumption microwave detection method not only takes full advantage of the strong robustness and an unique electric transmission characteristic showed by the topological surface state, but also takes advantage of microwave resonance of the antiferromagnetic layer, thereby enabling the structure to achieve passive low-power-consumption microwave detection.

Disclosed are a fin-type field effect transistor and a formation method thereof. The formation method of the fin-type field effect transistor includes the following steps: providing a substrate and forming a fin part on the substrate; selectively growing a topological insulator layer on the surface of the fin part; forming a gate dielectric layer which covers the topological insulator layer and forming a first gate electrode which crosses the insulating dielectric layer; respectively removing the gate dielectric layer and the topological insulator layer at the two ends of the fin part and forming epitaxial layers with doping on the surface of the exposed fin part, wherein the epitaxial layers are separated with the first gate electrode by the remaining gate dielectric layer and the topological insulator layer, and the epitaxial layers with doping, at the two ends of the fin part, are used as a source electrode and a drain electrode respectively; applying a voltage between the source electrode and the drain electrode so that the surface of the topological insulator layer is switched on and the surface of the topological insulator layer is used as a channel area; and applying a voltage between the gate electrode and the source electrode, wherein an electric field caused by the voltage is capable of adjusting the carrier concentration on the surface of the topological insulator body. Carriers in the channel area do not collide or interfere so that the mobility ratio of the carriers is improved.

A method for forming a topological insulator structure is provided. A strontium titanate substrate having a surface (111) is used. The surface (111) of the strontium titanate substrate is cleaned by heat-treating the strontium titanate substrate in the molecular beam epitaxy chamber. The strontium titanate substrate is heated and Bi beam, Sb beam, Cr beam, and Te beam are formed in the molecular beam epitaxy chamber in a controlled ratio achieved by controlling flow rates of the Bi beam, Sb beam, Cr beam, and Te beam. The magnetically doped topological insulator quantum well film is formed on the surface (111) of the strontium titanate substrate. The amount of the hole type charge carriers introduced by the doping with Cr is substantially equal to the amount of the electron type charge carriers introduced by the doping with Bi.