35 results about "Polar crystal" patented technology

The present invention relates to a light emitting device having a plurality of non-polar light emitting cells and a method of fabricating the same. Nitride semiconductor layers are disposed on a Gallium Nitride substrate having an upper surface. The upper surface is a non-polar or semi-polar crystal and forms an intersection angle with respect to a c-plane. The nitride semiconductor layers may be patterned to form light emitting cells separated from one another. When patterning the light emitting cells, the substrate may be partially removed in separation regions between the light emitting cells to form recess regions. The recess regions are filled with an insulating layer, and the substrate is at least partially removed by using the insulating layer.

The present invention discloses a high beta crystal form content polyvinylidene fluoride composite material and a preparation method thereof. The composite material comprises ionic liquid modified carbon nanotubes and an organic material polyvinylidene fluoride, wherein a mass ratio of the polyvinylidene fluoride substrate to the modified carbon nanotubes is 100:0-12, and a mass ratio of the ionic liquid to the carbon nanotubes is 0-10:1. The preparation method comprises: carrying out coating modification on carbon nanotubes by using an ionic liquid, carrying out melt blending on the modified carbon nanotubes and polyvinylidene fluoride, and carrying out direct melt molding cooling to obtain the finished product. According to the present invention, polar crystal form content of PVDF in the prepared composite material can be 100%, the preparation process has characteristics of simpleness, energy source saving, and green environment protection, and the polyvinylidene fluoride composite material is expected to be provided for preparing various devices in fields such as piezoelectric materials, thermoelectric materials, dielectric materials and the like.

A method and device for generating terahertz radiation comprising a polar crystal material layer operative to emit terahertz radiation; the polar crystal material layer comprising a plurality of stacking faults; the stacking faults lying substantially perpendicular to the polar axis and forming boundaries at which the internal electric polarization terminates leading to charges accumulating at the boundaries, and creation of internal electric fields oriented along the polar axis; a pulsed radiation source for creating photogenerated carriers in the polar crystal material; whereby the photogenerated carriers accelerate in the internal electric fields associated with the termination of the internal electric polarization by the stacking faults to thereby generate terahertz radiation.

The invention discloses polar crystal-form polyvinylidene fluoride and a preparation method of a composite thereof. The preparation method includes: adding CTAB (cetyltrimethyl ammonium bromide) serving as nucleating agents so as to obtain high-content polar crystals, using 40%-99.9% of PVDF (polyvinylidene fluoride), 0.1%-10% of the cetyltrimethyl ammonium bromide and 0%-50% of packing as raw materials, uniformly mixing the raw materials by solution mixing or melting mixing, and forming so that the target composite is obtained. Highly-polar crystal-form PVDF material and the composite thereof are prepared by adding the CTAB playing a remarkable role in nucleation of polyvinylidene fluoride polar crystal forms. The composite can be formed by the aid of various methods (solution method and melting method) and various processing equipment (extruding, injection molding and mould pressing), and the preparation method is simple and convenient.

According to one aspect, the present invention concerns a terahertz modulator (1) intended to be used in a given frequency band of use. The modulator comprises a semi-conductor polar crystal (330) presenting a Reststrahlen band overlapping said frequency band of use and presenting at least one interface with a dielectric medium, coupling means (330) allowing the resanant coupling of an interface phonon polariton (IPhP) supported by said interface and of an incident radiation (2) of pre-determined frequency lying in said frequency band of use and means of control (22) apt to modify the intensity of the coupling between said interface phonon polariton and said incident radiation (2) by modification of the dielectric function of the polar crystal in the Reststrahlen band of the polar crystal (10).

The invention relates to a method of electro-optic Q-switching of a solid laser, and in particular to a method for realizing high repetition frequency electro-optic Q-switching by using a periodic polar crystal as an electro-optic Q switch. The method at least comprises a pumping source, a coupling system and a resonant cavity which form the laser. The resonant cavity comprises a laser medium and an output mirror, wherein two isodirectional polaroids are arranged between the laser medium and the output mirror; and the periodic polar crystal is arranged between the two polaroids. The method is characterized in that voltage is loaded on the periodic polar crystal through a back-pressure type Q switch power supply so that the crystal axial direction of each electric domain just defects to the angle theta capable of realizing oscillation laser Saco filtration, then the polarization direction of the oscillation laser through the periodic polar crystal rotates by 90 degrees, failing to form oscillation through the second isodirectional polaroid; as a result, the energy-level particles on the laser medium are accumulated; when the on-load voltage loses transiently, the resonant cavity starts oscillation rapidly to form laser pulse and output. In the invention, the required on-load voltage is relatively low, therefore the operation of the high repetition frequency electro-optic Q-switching of the solid laser is easily achieved.

Provided is a semiconductor device fabrication apparatus comprising: a filter which contains a polar crystal, and filters pure water or a liquid containing pure water as a solvent; and a working section which has a pressing mechanism configured to apply a pressure to said filter, and supplies the filtered pure water or the filtered liquid containing pure water as a solvent to a surface of an object to be polished or cleaned, thereby performing a polishing process or cleaning process.

A method and device for generating terahertz radiation comprising a plurality of layers of polar crystal material operative to emit terahertz radiation; the plurality of layers comprising transport layers and divider layers, the plane of the layers being not parallel to the polar axis, the interface between the transport layers and divider layers forming boundaries at which the internal electric polarization terminates leading to charges accumulating at the boundaries, and creation of internal electric fields oriented along the polar axis.

The invention provides a battery coating film slurry, a battery diaphragm and secondary battery and respective preparation methods thereof. The preparation of the battery coating film slurry comprisesthe steps: providing a polymerization unit including vinylidene fluoride and a fluorine-containing polymerization unit, providing a nucleating agent and adding the nucleating agent in the polymerization process of the polymerization unit so as to obtain a modified polymer; and preparing the battery coating film slurry based on the modified polymer. With application of the technical scheme, the battery coating film slurry is designed, the non-aqueous system is used, the diaphragm and the pole piece can be bonded together to improve the hardness of the battery, and the crystal form of the prepared polymer is transformed to the polar crystal form, the crystal structure is more perfect, the crystallinity is higher, the swelling ratio is low and the adhesion performance is superior; and the prepared battery has lower internal resistance and better cycling performance. The polymer is dispersed by using the aqueous system so that the shortage of the copolymer prepared by the oil-based systemcan be solved, the advantage of the aqueous polymer coating product can be exerted and the environmental protection effect can be further improved.

The invention relates to a gallium nitride crystal manufacturing method and a substrate. The method comprises the following steps: carrying out first epitaxial growth under in a first atmosphere to form a first gallium nitride crystal layer on a patterned surface of a sapphire substrate; and carrying out second epitaxial growth in a second atmosphere different from the first atmosphere to form a second gallium nitride crystal layer on the surface of the first gallium nitride crystal layer. With the manufacturing method, the gallium nitride crystal with a smooth semi-polar crystal face can be obtained with a mode of not using chemical mechanical polishing.

A method of growing a group III nitride crystal structure comprises: providing a silicon substrate(12); forming a first mask (10) on the substrate, the mask having a plurality of apertures (14) through it each exposing a respective area of the silicon substrate; etching the silicon exposed by each of the apertures to form a respective recess(16)having a plurality of facets(18, 20, 22, 24); depositing a second mask over some of the facets of each recess leaving at least one of the facets(22)of each recess exposed; and growing group III nitride on the exposed facets(22) and then over the substrate to form a continuous layer.

The invention provides a method of utilizing a spontaneous polarization built-in electric field in a ZnO single crystal to adjust and control separation efficiency and optic electrochemical property of photon-generated carriers in a photoelectrode of the ZnO single crystal. Through adjusting direction of the polarization built-in electric field in the electrode of the ZnO single crystal, separation efficiency of photon-generated carriers in the electrode of the ZnO single crystal is controlled to regulate and control light current and photoelectric conversion efficiency. When the direction of the built-in electric field in the ZnO single crystal is perpendicular to the surface of the electrode and points to the outer surface (O-SC), light current, quantum conversion efficiency and separation efficiency of carriers in the electrode are effectively enhanced. The method is simple and effective to further improve the separation efficiency and activity of carriers of the photoelectrode of photoelectrochemistry and has potential application value.

The invention provides a production method of a high response ultraviolet detector, and belongs to the technical field of semiconductor device preparation. A mask layer with a strip-shaped or cross-shaped groove window is formed on a GaN seed crystal layer, and a growth mask is controlled to be arranged along a specified crystal orientation, then an MOCVD selective transverse epitaxy process is utilized to obtain a semi-polar crystal face AlxGa1-xN material with the low defect density, and finally a metal interdigital structure electrode is prepared on the surface of the AlxGa1-xN material toform a Schottky contact, so as to realize the high response ultraviolet detector.

The invention discloses a preparation method of a graphene oxide-fluorine-containing piezoelectric plastic composite membrane. The preparation method comprises the following steps of mixing graphene oxide, water, a coupling agent and methoxypolyethylene glycol amine, and performing modification treatment on the graphene oxide to obtain polyethylene glycol modified graphene oxide; mixing the polyethylene glycol modified graphene oxide, an organic solvent and fluorine-containing piezoelectric plastics to obtain a mixed solution, and drying the mixed solution to obtain a mixed material of the polyethylene glycol modified graphene oxide and the fluorine-containing piezoelectric plastics; and pressing the mixed material to form a membrane under the condition with the temperature of 200-220 DEGC to obtain the graphene oxide-fluorine-containing piezoelectric plastic composite membrane. According to a recordation of the embodiment of the invention, the polar crystal content of the graphene oxide-fluorine-containing piezoelectric plastic composite membrane prepared by utilizing the preparation method is 68 percent or above.

The invention provides a transparent high-electroactivity polyvinylidene fluoride based composite material and a preparation method therefor and belongs to the fields of macromolecular materials and advanced nanocomposite materials. The composite material is obtained through blending polyvinylidene fluoride, ionic liquid and clay according to a mass ratio of 100: (0.05 to 10): (0.01 to 3). The invention further provides the preparation method for the transparent high-electroactivity polyvinylidene fluoride based composite material. The composite material provided by the invention has high permeability and 100% polar crystals; in addition, the clay can inhibit the ionic liquid from migrating in an electric field, the dielectric loss of the composite material is lowered, and thus, the application of the composite material as a piezoelectric material is widened.

The present invention provides a control method to epitaxial growth monolayer graphene, in which a monolayer graphene is epitaxially grown on a non-polar crystal face at arbitrary angle of a non-polar crystal face SiC substrate, thereby utilizing the non-polar crystal face to manipulate the electrical transport properties of graphene. A monolayer graphene having ballistic transport properties can be epitaxially grown at arbitrary angle of non-polar crystal face SiC substrate by the above-mentioned control method.

The invention discloses a polar crystal La3SbS4OCl2 and a preparation method thereof, and relates to the technical field of intraocular lens, the crystal is a sulfur-oxygen-chlorine mixed anion compound with a non-centrosymmetric structure, the crystal system is a hexagonal crystal system, the space group is P63mc, and the unit cell parameter unit cell volume is prepared in a way that under the protection of inert gas according to the stoichiometric ratio of La3SbS4OCl2, elemental lanthanum, lanthanum trichloride, elemental antimony, antimony trioxide and elemental sulfur are mixed and then put into a quartz tube, vacuumized, heated to 920-980 DEG C, a solid-phase chemical reaction is performed, and cooling is performed, thereby obtaining the product. According to the invention, the anti-laser-damage functional element is utilized to regulate and control the SbS3 triangular pyramid structure units of the polar functional element to realize equidirectional arrangement, so that the spontaneous polarization intensity is increased, the non-centrosymmetric structure is assembled on the molecular level, and the polar crystal La3SbS4OCl2 is successfully synthesized. The polar crystal has strong spontaneous polarization intensity and high laser damage threshold.

The invention provides a battery coating film slurry, a battery separator, a secondary battery and their respective preparation methods. The preparation of the battery coating film slurry includes: providing a polymer unit, the polymer unit comprising vinylidene fluoride and a fluorine-containing polymer unit , providing a nucleating agent, adding the nucleating agent during the polymerization of the polymerization unit to obtain a modified polymer; and preparing the battery coating film slurry based on the modified polymer. Through the above technical solution, the present invention designs the battery coating film slurry, and adopts a non-aqueous system, which can not only bond the diaphragm and the pole piece together, improve the hardness of the battery, but also the crystal form of the polymer prepared Polar crystal transformation, more complete crystal structure and higher crystallinity, smaller swelling ratio, better bonding performance; the manufactured battery has smaller internal resistance and better cycle performance. The water-based system is used to disperse the polymer, which solves the shortcomings of the oil-based system for preparing copolymers, gives full play to the advantages of water-based polymer coating products, and further improves the environmental protection effect.

A support of two luminous polar crystals is prepared as setting two carrying units with fixed height drop on support, utilizing higher carrying unit to set luminous chip and utilizing relatively lower carrying unit to set static resisting chip to let light source generated by luminous chip free block of static resisting chip.

The invention belongs to the technical field of semiconductor material preparation, and provides a metal organic compound chemical vapor deposition (MOCVD) process on SiO 2 A method for preparing a nonpolar a-plane GaN epitaxial layer from a substrate. SiO 2 The substrate is nitrided at 1200‑1300°C under the condition of high temperature and large ammonia gas flow rate of 4000‑4500 sccm. After the treatment, SiO 2 a-Si with close-packed hexagonal structure formed on the substrate surface 3 N 4 Thin layer; a-plane oriented GaN crystal nucleus layer is grown on the thin layer, and finally a-plane GaN epitaxial layer is grown on the basis of non-polar crystal nucleus. Compared with the widely used polar c-plane GaN, the non-polar a-plane GaN-based device eliminates the quantum confinement Stark effect caused by the polarization effect, has high internal quantum efficiency, and has no light emission at high current density. Advantages such as wavelength drift.