67 results about "Graphene monolayer" patented technology

The invention generally related to a method for preparing a layer of graphene directly on the surface of a substrate, such as a semiconductor substrate. The layer of graphene may be formed in direct contact with the surface of the substrate, or an intervening layer of a material may be formed between the substrate surface and the graphene layer.

Technologies are generally described for perforated graphene monolayers and membranes containing perforated graphene monolayers. An example membrane may include a graphene monolayer having a plurality of discrete pores that may be chemically perforated into the graphene monolayer. The discrete pores may be of substantially uniform pore size. The pore size may be characterized by one or more carbon vacancy defects in the graphene monolayer. The graphene monolayer may have substantially uniform pore sizes throughout. In some examples, the membrane may include a permeable substrate that contacts the graphene monolayer and which may support the graphene monolayer. Such perforated graphene monolayers, and membranes comprising such perforated graphene monolayers may exhibit improved properties compared to conventional polymeric membranes for gas separations, e.g., greater selectivity, greater gas permeation rates, or the like.

The invention discloses a method for rapidly and nondestructively transferring graphene. The method comprises the following steps of: (1) coating a thermosetting adhesive or an optical curing adhesive on the surface of a target substrate; (2) attaching the surface of the target substrate, which is obtained in the step (1) and is coated with the thermosetting adhesive or the optical curing adhesive, to the graphene, thus forming a target substrate/graphene/growth substrate composite structure; (3) performing hot-press treatment or UV-irradiation curing treatment on the target substrate/graphene/growth substrate composite structure obtained in the step (2); (4) performing growth substrate stripping on the target substrate/graphene/growth substrate composite structure treated in the step (3). The large-area high-quality graphene can be transferred to the target substrate under the condition that the growth substrate is not corroded, the obtained graphene has a high single-layer property and relatively high uniformity, the pollution of organic adhesive residues and metal substrate dissolution on the graphene in the transfer process is avoided, and the growth substrate can be repeatedly used and is economic and environment-friendly.

The invention relates to the technical field of graphene production methods, in particular to a dry type stripping production process of graphene nano powder. The dry type stripping production processincludes the steps of firstly, heating to expand expandable graphite with high expansion times under inert or reduction atmosphere to obtain graphite worms; secondly, subjecting the collected graphite worms to ultrahigh-speed rotary shearing in a crushing cavity to obtain graphite micro-sheets; thirdly, processing the graphite micro-sheets in a high-pressure container on a vibration platform; fourthly, subjecting the graphite micro-sheets flowing out of the high-pressure container to continuous stripping in an ultrasonic stripping cavity to obtain the graphene nano powder. The obtained graphene nano powder is large in single-layer sheet diameter, few in layers, good in universality, high in conductivity, low in resistance, high in specific surface area and low in production cost.

The use of silicon or vanadium oxide nanocomposite consisting of graphene deposited on top of an existing amorphous silicon or vanadium oxide microbolometer can result in a higher sensitivity IR detector. An IR bolometer type detector consisting of a thermally isolated nano-sized (<one micron feature size) electro-mechanical structure comprised of Si3N4, SiO2 thins films, suspended over a cavity with a copper thin film reflecting surface is described. On top of the suspended thin film is a nanostructure composite comprised of graphene monolayers, covered with various surface densities of VoXy or amorphous nanoparticles, followed by another graphene layer. The two conducting legs are connected to a readout integrated circuit (ROIC) fabricated on a CMOS wafer underneath. The nanostructure is fabricated after the completion of the ROIC process and is integrate able with the CMOS process.

The invention relates to a method for preparing monolayer graphene with controllable stripe width on a substrate by utilizing laser beam heating through a grating, belonging to the technical field of semiconductor novel materials. Graphene has higher electron transport properties, good response frequency and wider light band transparency, and can achieve the optimization of high-speed electronic device fabrication. Therefore, the realization of growth of high-quality stripe-shaped graphene materials is important for the development of electronic technology. Through the method, stripe-shaped monolayer graphene is prepared by heating the substrate with lasers through the grating, the lithography step is omitted, the method is performed by one step and is simple and feasible, and the growth materials are not polluted by additional materials; and at the same time, the laser beams can be quickly removed, the method has the characteristics of rapid temperature reduction and the like, the unnecessary multi-layer graphene growth can be reduced, the graphene monolayer growth is effectively realized, and the method is characterized by acquiring the discrete beams through the grating, thus obtaining the discrete stripe-shaped monolayer graphene.

A scaffold-free 3D porous electrode comprises a network of interconnected pores, where each pore is surrounded by a multilayer film including a first layer of electrochemically active material, one or more monolayers of graphene on the first layer of electrochemically active material, and a second layer of electrochemically active material on the one or more monolayers of graphene. A method of making a scaffold-free 3D porous electrode includes depositing one or more monolayers of graphene onto a porous scaffold to form a graphene coating on the porous scaffold, and depositing a first layer of an electrochemically active material onto the graphene coating. The porous scaffold is removed to expose an underside of the graphene coating, and a second layer of the electrochemically active material is deposited onto the underside of the graphene coating, thereby forming the scaffold-free 3D porous electrode.

The invention discloses a preparation method of an in-situ-polymerization graphene microemulsion. The method comprises the following steps: 1. adding 400mL of deionized water into a flask; 2. adding 1-10g of intercalation agent, and sufficiently dissolving; 3. adding 4-50g of graphene, and stirring and dispersing for 15 minutes; 4. treating with an ultrasonic treatment device for 15-30 minutes, wherein the ultrasonic power is greater than 500 watts; 5. heating to 70 DEG C, and adding 2.4-30g of emulsifying micelle protective agent; 6. adding 200mL of 2% hydroxypropyl methylcellulose ether water solution, and sufficiently stirring; and 7. treating in the ultrasonic treatment device for 60-120 minutes, wherein the ultrasonic power is greater than 500 watts. Under the high-power ultrasonic action, the intercalation agent is intercalated into the graphene laminae to obtain the monolayer graphene; the micelle protective agent protects the graphene monolayer to form a nano microscopic micelle; and the graphene is dispersed in the nano monolayer in the microemulsion, can be stored stably, and can be used for in-situ polymerization.

Described herein are methods for improved transfer of graphene from formation substrates to target substrates. In particular, the methods described herein are useful in the transfer of high-quality chemical vapor deposition-grown monolayers of graphene from metal, e.g., copper, formation substrates via non-polymeric methods. The improved processes provide graphene materials with less defects in the structure.

A method of fabricating a graphene device generally involving depositing a graphene monolayer from a carbon source on a metal catalyst layer; depositing a transfer substrate on the graphene monolayer by way of casting, thereby forming a transfer-substrate/graphene/metal-catalyst structure; annealing the transfer-substrate/graphene/metal-catalyst structure, thereby forming an annealed transfer-substrate/graphene/metal-catalyst structure; coupling a thermal adhesive with the transfer-substrate/graphene/metal-catalyst structure; moving the annealed transfer-substrate/graphene/metal-catalyst structure to a target area of a target device, by using a probe assembly or the like, thereby forming an annealed transfer-substrate/graphene/metal-catalyst/thermal-adhesive/target-device structure; releasing the slip of thermal adhesive from the annealed transfer-substrate/graphene/metal-catalyst thermal-adhesive/target-device structure by applying heat, thereby forming an annealed transfer-substrate/graphene/metal-catalyst/target-device structure; etching away the metal catalyst layer from the annealed transfer-substrate/graphene/metal-catalyst/target-device structure in an etching solution, thereby forming a graphene/transfer-substrate/target-device structure; rinsing the graphene/transfer-substrate/target-device structure with DI water, thereby removing any excess etching solution; and drying the graphene/transfer-substrate/target-device structure, thereby providing the graphene device.

An asbestos-free friction material includes inorganic and/or organic and/or metallic fibers, at least one binder, at least one friction modifier or lubricant, at least one filler or abrasive and a carbonaceous material constituted by a microstructure. The microstructure is in the form of flakes or scales of micrometric planar dimensions and of nanometric thickness consisting of a substantially pure graphene mono- or multilayers, preferably pre-blended with at least part of the organic binder.