21 results about "Tungsten diselenide" patented technology

The invention discloses a method for preparing a single-layer tungsten diselenide nanoband based on a space confinement strategy. By changing the flow and the growth time of hydrogen, effective control on the width and the thickness of a nanoband can be realized. The method comprises the following steps: uniformly spraying tungsten trioxide powder to one substrate, then covering the substrate by the other substrate, and forming micro reaction space which is of a 'sandwich'-like structure. Growth of a tungsten diselenide nanoband is carried out by utilizing a constant-pressure chemical vapor deposition method; physicochemical characteristics of a one-dimensional transition metal chalcogenide strongly depend on suspension key types on the edge of the one-dimensional transition metal chalcogenide, metallic properties are displayed by an ultranarrow band, and conversion from the metallic properties to semiconductor properties can be displayed from the edge to the center of a wider band; the tungsten diselenide nanoband is widely applied to micro-nano photoelectric devices due to the special property; industrial production of the tungsten diselenide nanoband can be realized through an experimental method of the invention.

This invention provides a charge-trapping type two-dimensional horizontal homojunction rectifier and its fabrication method, relating to the field of semiconductor electronics technology. It enables p-doping and n-doping of bipolar two-dimensional tungsten diselenide using graphodyne and a silicon dioxide insulating layer under a positive gate electric field. The resulting p-n junction achieves a large rectification ratio and stable rectification performance. This rectifier simultaneously performs n-type and p-type doping on the two-dimensional tungsten diselenide, forming a p-n homojunction in the horizontal direction. This allows the output current to exhibit high and low levels depending on the polarity of the input drain-source voltage, thus achieving the rectifier function. The rectifier achieves p-type and n-type doping under the influence of a positive gate electric field applied by the silicon gate electrode, through simultaneous contact between a portion of the two-dimensional tungsten diselenide with the graphodyne film and the silicon dioxide insulating layer, forming a homojunction. The technical solution provided by this invention is applicable to the rectification process.

The application discloses a high-temperature heat-stable two-dimensional field effect transistor and a preparation method, and mainly solves the problem that two-dimensional materials in the two-dimensional field effect transistor are oxidized and decomposed at high temperature. The two-dimensional field effect transistor comprises, from bottom to top, a substrate (1), an insulating encapsulation protection bottom layer (2), a two-dimensional material thin film layer (3), an insulating encapsulation protection top layer (6), a gate electrode (7), source electrodes (4) and drain electrodes (5) at two ends of the thin film layer (3), and the encapsulation protection bottom layer and the encapsulation protection top layer are both made of any one or a plurality of combinations of aluminum nitride, hexagonal boron nitride or silicon nitride, so that oxygen molecules in air are prevented from diffusing to the two-dimensional material thin film layer to react at high temperature, and the two-dimensional material thin film layer plays a role in high-temperature protection; the two-dimensional material thin film layer is made of molybdenum disulfide, tungsten disulfide or tungsten diselenide. The two-dimensional field effect transistor has improved high-temperature resistance, and the oxidation and decomposition of the two-dimensional material at high temperature are avoided, and the two-dimensional field effect transistor can be used in aerospace, deep well drilling or other high-temperature environments.

This invention relates to a method for preparing and applying a ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide, belonging to the field of gas sensor technology. The invention discloses a ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide and its application as a sensing material in a highly selective and sensitive flexible NO2 gas sensor. The invention utilizes a liquid-phase growth method, using SnSe2 nanosheets, ammonium tungstate, and diphenyldiselenoether as raw materials, and varying reaction conditions such as temperature, reaction time, and raw material content to prepare the ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide. Subsequently, these nanosheets are sprayed onto interdigitated electrodes and dried to form a film, thus preparing a chemielectric resistive gas sensor capable of detecting low concentrations of nitrogen dioxide gas at room temperature. It not only possesses high sensitivity and selectivity but can also be applied to flexible NO2 gas sensing.

The invention relates to a preparation method of a single-layer tungsten diselenide single-crystal thin film, which comprises the following steps: taking a tungsten source, ferrous chloride and a selenium source as raw materials, taking inert gas as carrier gas, adopting a chemical vapor deposition method, and carrying out three-temperature-zone heating growth to obtain the tungsten diselenide single-crystal thin film. According to the method, the growth process is simple and easy to operate, the preparation process is accurate and controllable, the domain orientation of the obtained single-layer tungsten diselenide crystal is consistent, no domain grain boundary exists, and the thickness uniformity and the crystal quality are excellent.

The invention discloses a two-dimensional semiconductor p-type field effect transistor based on transition metal oxide contact and a preparation method thereof, and relates to the technical field of semiconductor micro-nano electronic devices, and the preparation method comprises the steps: forming a single-layer tungsten diselenide on a substrate as a channel layer; defining pattern windows of a source electrode and a drain electrode on the surface of the channel layer to form an electrode region and a non-electrode region; sequentially depositing molybdenum trioxide and gold on the pattern windows of the source electrode and the drain electrode by adopting a thermal evaporation process to form a molybdenum trioxide / gold composite electrode structure; and removing the photoresist and sediments above a non-electrode region through a stripping process to prepare the two-dimensional semiconductor p-type field effect transistor based on transition metal oxide contact. The preparation of the high-performance two-dimensional semiconductor p-type field effect transistor is realized by introducing the ultrahigh work function molybdenum trioxide as the buffer layer and combining a mild process.

The application discloses a preparation method of high-temperature-resistant extreme-pressure lubricating oil and relates to the technical field of lubricating materials. The fluorosilicone oil is prepared by using 1,1,3,3-tetrachloro-1,3-diphenyl disiloxane and methyl trifluoropropyl cyclotrisiloxane as raw materials, contains multiple benzene rings and chlorine atoms, can improve the high-temperature resistance and stability of the fluorosilicone oil, can help to form a more stable lubricating film on a friction surface, and can improve the extreme-pressure resistance of the fluorosilicone oil. Then, bentonite and a tungsten diselenide precursor solution are mixed, and the tungsten diselenide is directly prepared on the surface of the bentonite by using an ultrasonic pyrolysis method. The ultrasonic wave makes the tungsten diselenide better combine with active sites on the surface of the bentonite, improves the loading capacity of the tungsten diselenide, reduces the aggregation and loss of the tungsten diselenide additive during use, prolongs the service life of the tungsten diselenide additive, and further improves the high-temperature resistance and extreme-pressure resistance of the system. The prepared lubricating oil has the effects of high-temperature resistance and extreme-pressure resistance.

This invention provides an environmentally friendly flame-retardant PC resistant to high glow wire and its preparation method. The PC comprises: a matrix PC resin 1, a matrix PC resin 2, a branched PC resin, and tungsten diselenide nanoparticles. The material prepared by this invention not only has the advantages of high glow wire resistance and anti-dripping properties, but also has certain environmental value because the polymer material prepared by this invention does not use halogen-based flame retardants and requires less anti-dripping agent.

The application discloses a preparation method of an optical dielectric microsphere array / single layer of tungsten diselenide composite structure applied to improve valley polarization, and the optical dielectric microsphere dispersion liquid is dropped on the single layer of tungsten diselenide to obtain the optical dielectric microsphere array / single layer of tungsten diselenide composite structure through a self-assembly method. The optical dielectric microsphere array / single layer of tungsten diselenide composite structure obtained by the application has excellent valley polarization photoelectric performance, and provides a new scheme for design, manufacture and application of valley electronic devices.

This invention belongs to the technical field of potassium-ion battery electrode materials. It discloses tungsten disulfide / tungsten diselenide electrode materials, their preparation methods, and their applications. The method involves mechanically mixing bulk tungsten disulfide / tungsten diselenide materials obtained through high-temperature reactions with small-sized ionic liquids or small organic molecules. The ionic liquids or small molecules act as intercalating agents, inserting into the interlayer spaces of the tungsten disulfide / tungsten diselenide molecules to regulate the interlayer structure, resulting in expanded and exfoliated ultra-dispersed tungsten disulfide / tungsten diselenide materials. Ferromagnetic metal cations are then introduced into these ultra-dispersed tungsten disulfide / tungsten diselenide materials to obtain ferromagnetically doped ultra-dispersed tungsten disulfide / tungsten diselenide electrode materials. This invention utilizes a combined "intercalation-exfoliation-cation doping" strategy to obtain tungsten disulfide / tungsten diselenide electrode materials with large interlayer spacing, small size, few layers, ultra-dispersion, and certain ferromagnetic properties, suitable for use as a negative electrode material in potassium-ion batteries, achieving a capacity of up to 336 mAh·g. ‑1 .

This invention provides a palladium diselenide / tungsten diselenide vertical heterojunction field-effect transistor, its fabrication method, and its application, belonging to the field of semiconductor device technology. The palladium diselenide / tungsten diselenide vertical heterojunction field-effect transistor comprises, from bottom to top, a substrate, a vertical heterojunction, and a metal electrode; the vertical heterojunction includes a tungsten diselenide layer covering the substrate and a palladium diselenide layer covering the tungsten diselenide layer. This invention first constructs a tungsten diselenide layer on the substrate using chemical vapor deposition (CVD), and then directly grows a palladium diselenide layer on the surface of the tungsten diselenide layer using CVD. This vertical heterojunction field-effect transistor exhibits excellent performance with high saturation current density, high carrier mobility, and a high current on / off ratio, solving the technical problem of low performance and incompatibility with two-dimensional n-type semiconductor field-effect transistors in current two-dimensional p-type semiconductor devices.

The invention relates to the technical field of chemical power sources, in particular to a bimetallic selenide modified alkali metal negative electrode material and a preparation method and application thereof.The preparation method comprises the steps that prepared vanadium atom doped tungsten diselenide (VxWSe) powder is evenly coated on the surface of sodium / potassium metal, an adjustable interface protection layer is constructed, and the surface of the sodium / potassium metal is coated with the bimetallic selenide modified alkali metal negative electrode material; and the adsorption and transfer of sodium / potassium ions are optimized by utilizing the unique layered structure. The controllable interface protection layer can provide excellent dendrite growth prevention and desolvation functions, and the cycle life of the alkali metal battery is greatly prolonged by reducing side reactions. In addition, the preparation method has the advantages that the operation is simple, modification factors are easy to control, and large-scale production can be realized.

The application relates to a preparation method and application of a tungsten diselenide nanomaterial. The method adopts a direct current arc plasma discharge method, tungsten powder and selenium powder are uniformly mixed according to a certain material molar ratio, pressed into a block, placed in an anode graphite pot of a reaction chamber, and a cathode tungsten rod is horizontally arranged opposite to the anode graphite pot. The discharge reaction is carried out in a water cooling system and an argon atmosphere protection, and after cooling and passivation, WSe2 nanomaterial is obtained at a condensing wall sleeve and a graphite pot. Meanwhile, the WSe2 nanomaterial is used for Li2S6 solution adsorption capacity test. The preparation process is simple, the material consumption is small, the repeatability is high, the sample yield and purity are ensured, and the method is suitable for large-scale industrial production. In addition, as a strong adsorption material of polysulfide, the WSe2 nanomaterial has good application prospect in the battery field.

This invention relates to the field of batteries, and more particularly to a nitrogen-doped carbon / tungsten diselenide nanosphere composite material, its preparation method, and its applications. This invention achieves tight coupling between few-layer WSe2 nanosheets and a nitrogen-doped carbon framework through a process combining complexation-polymerization and subsequent selenization. The resulting material consists of nanosphere particles, providing more electrochemical active sites and shortening the zinc ion diffusion distance. By introducing a nitrogen-doped carbon framework, this invention effectively improves the overall conductivity of the composite material and suppresses the stacking and aggregation of WSe2 nanosheets during charge and discharge, thereby significantly improving rate performance and cycle stability.

The utility model relates to a reconfigurable grid-control filter circuit, which comprises a reconfigurable transistor, the reconfigurable transistor adopts semimetal carbon nano tube electrode contact and tungsten diselenide channel materials, boron nitride is used as a gate medium, metal gold is used as a bottom gate electrode, and the bottom gate electrode is used as a gate electrode. The drain electrode of the reconfigurable transistor serves as the signal input end of the circuit, the source electrode of the reconfigurable transistor is grounded, and the grid electrode of the reconfigurable transistor serves as the working state control end of the circuit and is used for receiving grid electrode voltage to regulate and control the working state of the reconfigurable transistor; the resistance value of the pull-down resistor is 500 megohms, one end of the pull-down resistor is connected to a node between the source electrode of the reconfigurable transistor and the ground, and the other end of the pull-down resistor serves as a signal output end of the circuit. The circuit can realize a grid-controlled rectifying and filtering function, and can sequentially show five functional modes of all-pass, positive-pass, all-off, reverse-pass and all-pass through regulation and control of grid voltage.

The invention discloses a method for improving the photoluminescence intensity of a single-layer tungsten diselenide WSe2 single crystal, and belongs to the technical field of two-dimensional material photoelectric devices, the single-layer WSe2 single crystal grown by a CVD (chemical vapor deposition) method is soaked or spin-coated by a methanesulfonic acid aqueous solution with the concentration of 10-40%, and the treated single-layer WSe2 single crystal is subjected to a photoluminescence test to obtain the photoluminescence intensity of the single-layer WSe2 single crystal. The single-layer WSe2 single crystal which is not subjected to acid treatment is weakest in luminescence, the fluorescence intensity is gradually enhanced and the half-peak width is weakened along with the increase of the concentration, 4.55 times of fluorescence enhancement is realized by soaking the single-layer WSe2 single crystal in methanesulfonic acid with the mass fraction of 40%, and the result of a second harmonic test shows that the result is more accurate. The single-layer WSe2 single crystal shows an obvious sextuple structure with the second harmonic intensity related to the polarization angle under the parallel condition, which indicates that the acid treatment under the dosage does not cause damage to the lattice structure. In addition, by building the back gate field effect transistor, it can be seen that the electrical performance after acid treatment is improved.

The application belongs to the technical field of photoelectric detectors, and discloses a non-refrigeration high-gain low-voltage avalanche photodetector based on a two-dimensional material heterojunction, which comprises, from bottom to top, a silicon (Si) substrate layer, a silicon dioxide (SiO2) dielectric layer, a rectangular electrode structure arranged at two ends of the SiO2 layer, and a heterojunction composed of an indium selenide (InSe) layer and a tungsten diselenide (WSe2) layer which are stacked alternately on the electrode. The InSe and the WSe2 form a type II band heterojunction, and efficient separation of carriers can be realized at the interface under a low bias voltage. The device structure directly utilizes the SiO2 dielectric and the rectangular electrode structure, realizes process simplification and good electrical isolation, can generate an avalanche effect under a low working voltage of less than 1V, and has an avalanche gain of 10 5 , has the advantages of low power consumption, high gain, good process compatibility, etc., and is suitable for weak light detection, high-sensitivity imaging and next-generation high-density photoelectric integrated systems.

The application provides a tungsten diselenide / nitrogen-doped porous carbon composite material, a modified diaphragm and a preparation method and application thereof. The tungsten diselenide / nitrogen-doped porous carbon composite material comprises nitrogen-doped porous carbon, and the pore channel of the nitrogen-doped porous carbon is filled with tungsten diselenide; wherein the mass ratio of tungsten diselenide to carbon in the nitrogen-doped porous carbon is (10-30):(90-70), and the doping amount of nitrogen in the tungsten diselenide / nitrogen-doped porous carbon composite material is 1-5 at.%. The application inhibits the shuttle effect caused by the dissolution of polysulfide into an organic electrolyte in the room-temperature sodium-sulfur battery cycle process by modifying the diaphragm with the tungsten diselenide / nitrogen-doped porous carbon composite material.

The invention discloses a method for green synthesis of a tungsten diselenide / platinum nano material and application thereof, and belongs to the technical field of biological detection materials. The preparation method comprises the following steps: adding a WSe2 nanosheet solution into an ethylene glycol solution, stirring at a constant speed, adding hexachloroplatinic acid for reaction, and centrifuging to obtain the tungsten diselenide / platinum nano material. The synthesis method provided by the invention is green and environment-friendly, simple to operate, low in cost and high in efficiency, and the prepared tungsten diselenide / platinum nano material has excellent oxidase catalytic activity and can be combined with diazotization reaction to realize quantitative analysis of nitrite in food. According to the colorimetric detection method of the tungsten diselenide / platinum nano material, provided by the invention, the detection limit of nitrite is 4.08 mu M, and the linear range is 5-400 mu M.

The application discloses a p-type tungsten diselenide field effect transistor based on 3R phase and a preparation method thereof, and belongs to the technical field of semiconductor devices. The device comprises a p-type doped silicon substrate, a silicon dioxide gate dielectric arranged on the p-type doped silicon substrate, a 3R phase double-layer tungsten diselenide channel material arranged on the silicon dioxide gate dielectric, and source-drain electrodes arranged on the surface of the 3R phase double-layer tungsten diselenide channel material. Meanwhile, a preparation method of the p-type tungsten diselenide field effect transistor based on 3R phase is provided. The p-type tungsten diselenide field effect transistor based on 3R phase prepared by the application can improve the electrical performance of the field effect transistor, and is beneficial to large-scale device integration of transition metal chalcogenides in the future.

The invention discloses a non-transfer rare earth doped tungsten diselenide heterojunction photoelectric device and a preparation method thereof, and belongs to the technical field of semiconductor photoelectric devices. The method comprises the following steps: carrying out cleaning and hydrofluoric acid activation treatment on a silicon substrate on a silicon-based insulator; the preparation method comprises the following steps: taking tungsten trioxide, erbium chloride, sodium chloride and selenium as precursors through a one-step chemical vapor deposition method, growing a single crystal erbium-doped tungsten diselenide film on an activated substrate silicon surface in an in-situ epitaxial growth manner, and directly constructing an erbium-doped tungsten diselenide / silicon Van der Waals heterojunction; and finally, preparing the electrode through photoetching, developing, metal deposition and stripping processes. According to the method, interface pollution caused by a traditional transfer process is thoroughly avoided, and high-concentration uniform erbium doping is realized by using a sodium chloride fluxing agent. The prepared heterojunction device has an atomic-scale clean interface and shows excellent photoelectric performance, the process is compatible with a complementary metal oxide semiconductor process, and a reliable platform is provided for high-performance silicon-based photoelectric integration.