89results about How to "Increase the bandgap width" patented technology

The invention provides CsxWOyFz powder and a preparation method thereof. The preparation method of the CsxWOyFz powder comprises the following steps: mixing a tungstic acid solution with a fluorine source solution, and adding organic acid to form a WO3-F composite sol; adding a Cs2CO3 solution to the WO3-F composite sol to form a Cs-WO3-F composite sol; putting the Cs-WO3-F composite sol in a high-pressure kettle, and carrying out hydrothermal reaction for 1-3 days at the temperature of 180-200 DEG C; and sequentially carrying out centrifugation, water washing, alcohol washing and drying on the reactant to obtain the CsxWOyFz powder. The preparation method provided by the invention has the advantages of no need for high temperature hydrogen reduction, simple process, low cost, little toxicity and benefit of scale production and practical application. The CsxWOyFz powder prepared by adopting the method has the advantages of excellent visible light transmission performance and near infrared shielding performance and broad application prospect in the aspects of light transmitting and heat insulating of buildings and automobile window glasses.

The present invention presents a solid-state semiconductor light emitting device with reduced forward voltage and improved quantum efficiency. The light emitting device is characterized by its multiple-quantum-well active-region with opposite composition grading in the quantum barriers and quantum wells along the device epitaxy direction.

The invention discloses a method for preparing an Ag/ZnO core-shell nanostructure by adopting pulse laser liquid ablation and belongs to the field of material preparation. Two-step pulse laser liquid ablation is adopted, oxide layers of an Ag target and a Zn target are removed by using nitric acid, and ultrasonic cleaning is performed. The method comprises the following steps of ablating the Ag target in deionized water by using excimer laser with the wavelength of 248nm, the single pulse energy of 400mJ and the repetition frequency of 10Hz to obtain Ag colloid; ablating the Zn target in the Ag colloid by using the same laser to obtain the Ag/ZnO core-shell nanostructure. According to the method, preparation equipment is simple, the preparation is quick and safe without pollution, the surface plasma resonance absorption of the prepared Ag/ZnO core-shell nanostructure can be adjusted, and the Ag/ZnO core-shell nanostructure has other excellent photoelectric properties and has a good application prospect in the fields of optics, electrics, catalysis and the like.

The invention discloses a manufacturing method of a hetero-junction solar cell. The manufacturing method of the hetero-junction solar cell comprises the steps that a substrate is provided; first intrinsic buffer layers are formed on one side or two sides of the substrate; second intrinsic buffer layers are formed on the two sides of the substrate with the first intrinsic buffer layers; doping layers, namely the first doping layer and the second doping layer, are formed on the two sides of the substrate with the second intrinsic buffer layers; transparent conducting layers are formed on the two sides of the substrate with the doping layers; or a transparent conducting layer is formed on one side of the substrate with the doping layers, and a transparent conducting oxide/metal composite layer is formed on the other side of the substrate with the doping layers. Therefore, the photoelectric conversion efficiency of the hetero-junction solar cell is improved. In addition, the invention provides the hetero-junction solar cell.

The invention discloses a gallium nitride power device with a multi-field plate structure. The gallium nitride power device is sequentially provided with a substrate, a nucleating layer, a buffer layer, a first insertion layer, a first GaN layer, a second insertion layer, a second GaN layer, an AlGaN barrier layer, a passivation layer, a grid electrode field plate, a drain electrode field plate, aprotective layer, a grid electrode insertion layer, a p-type GaN grid electrode, a grid electrode metal, a source electrode metal and a drain electrode metal from bottom to top, wherein the passivation layer located on the surface of the AlGaN barrier layer is in a strip shape arranged at intervals, the grid electrode field plate and the drain electrode field plate respectively cover part of thepassivation layer, and the surfaces of the grid electrode field plate and the drain electrode field plate and the space between the grid electrode field plate and the drain electrode field plate are covered with the protective layer. According to the invention, the electric field distribution is uniform, the voltage endurance capability of the device is enhanced, the stability of grid electrode turn-on voltage and grid electrode voltage of the device is effectively improved, and the electric leakage of the device under the action of large current is effectively reduced. The preparation methodis completely compatible with a traditional process, and the preparation difficulty is low.

The invention relates to a film solar battery based on crystalline silicon and a formation method thereof. The battery comprises a baseplate made of monocrystalline silicon or polysilicon, a photoelectric conversion unit positioned on the upper surface of the baseplate, an antireflection layer, a front electrode and a back electrode, wherein the photoelectric conversion unit successively comprises a P-type semiconductor layer, an I-type semiconductor layer and an N-type semiconductor layer,; the P-type semiconductor layer comprises multiple P-type semiconductor sublayers with different doped ion concentrations, and the P-type semiconductor sublayers are successively arranged in a stacking manner according to the doped ion concentrations; the N-type semiconductor layer comprises multiple N-type semiconductor sublayers with different doped ion concentrations, and the N-type semiconductor sublayers are successively arranged in a stacking manner according to the doped ion concentrations; the doped ion concentrations of the P-type semiconductor sublayer and the N-type semiconductor sublayer which are positioned on the surface of the I-type semiconductor layer are minimal; and the antireflection layer is positioned on the upper surface of the photoelectric conversion unit, the front electrode is positioned on the upper surface of the antireflection layer, and the back electrode is positioned on the lower surface of the baseplate. According to the invention, the photoelectric conversion efficiency can be improved.

The invention discloses a method of preparing an n-type counterfeit ternary erbium-doped thermoelectric material by utilizing a mechanical alloying cold pressing sintering method, and relates to a method of preparing a thermoelectric material. The invention solves the technical problems of easiness in separation, poor mechanical property and high material cost of the conventional thermoelectric material. The method comprises the following steps of: 1, mixing a simple substance Bi, a simple substance Sb, a simple substance Te and a simple substance Se, adding a rare earth element Er, and ball-milling to obtain alloy powder; 2, cold-pressing the alloy powder to a block at room temperature; 3, placing the cold-pressing block obtained in the step 2 into a high-temperature-resistant glass tube, sintering, and cooling to room temperature along with a furnace so as to obtain the n-type counterfeit ternary erbium-doped thermoelectric material. The material, prepared by the method in the invention, has a thermoelectromotive force rate close to an oriented crystal, according to the national departmental standard, the Seebeck coefficient of the material is tested to reach 200 muVK<-1>, the conductivity is 55 omega<-1>cm<-1>, and a power factor is close to 2 muWcm<-1>K<-2>.

The invention discloses a preparation method of a bismuth oxybromide ternary heterostructure photocatalyst. The method uses bismuth nitrate pentahydrate, potassium bromide, graphite phase carbon nitride and silver nitrate as raw materials; the prepared graphite phase carbon nitride and silver bromide are compounded with bismuth oxybromide so as to realize modification; the bismuth oxybromide ternary heterostructure photocatalyst is prepared by using a one-step solvothermal method. The modified bismuth oxybromide prepared by the method is purer, has a smaller forbidden band width and a higher visible light absorbing effect. The smaller forbidden band width reduces the transmission distance of photogenerated electron holes, improves the separation efficiency of the photogenerated electron holes, and reduces the recombination rate; the higher light absorption effect improves photon utilization rate, increases the yield of the electron hole pairs, and greatly improves the photocatalytic activity under the visible light. The method has the advantages of being low in cost and convenient to operate; the bismuth oxybromide ternary heterostructure photocatalyst can be used for degrading organic pollutants under the visible light, thus having an important practical value in environmental purification.

The present invention provides a preparation method of a high k-gate dielectric layer and a silicon carbide MOS power device. The preparation method comprises the steps of: performing high-temperaturesacrificial oxidation of a silicon carbide epitaxial wafer with a first conductive type, and forming a sacrificial oxidation layer at the upper surface of the epitaxial layer of the silicon carbide epitaxial wafer; performing corrosion of the sacrificial oxidation layer until the sacrificial oxidation layer on the epitaxial layer is completely removed; performing high-temperature surfacing processing of the upper surface of the epitaxial layer after removal of the sacrificial oxidation layer, and forming a smooth passivated surface; and depositing an Al2O3 dielectric coating layer, a LaAlO3 dielectric layer and an Al2O3 dielectric coating layer at the smooth passivated surface in order, performing annealing of a laminated structure formed by the Al2O3 dielectric coating layer, the LaAlO3dielectric layer and the Al2O3 dielectric coating layer, and forming a high k-gate dielectric layer. Compared to the prior art, the preparation method of the high k-gate dielectric layer and the silicon carbide MOS power device can reduce the interface defects caused by impurities and/or surface lattice defects at a SiC/SiO2 interface so as to improve the voltage endurance capability of the gate dielectric layer.

The invention relates to a thin film solar battery and a manufacturing method thereof. The thin film solar battery comprises a substrate, a first I-type semiconductor layer, a P-type semiconductor layer and a first electrode, a second I-type semiconductor layer, an N-type semiconductor layer and a second electrode, wherein the first I-type semiconductor layer, the P-type semiconductor layer and the first electrode are positioned at one side of the substrate in sequence, and the concentration of ions doped in the P-type semiconductor layer successively increases from the direction adjacent to the first I-type semiconductor layer to the direction far away from the first I-type semiconductor layer; the second I-type semiconductor layer, the N-type semiconductor layer and the second electrode are positioned at the other side of the substrate in sequence, and the concentration of ions doped in the N-type semiconductor layer successively increases from the direction adjacent to the second I-type semiconductor layer to the direction far away from the second I-type semiconductor layer. The invention has the beneficial effect that not only can the pollution of the P-type semiconductor layers or the N-type semiconductor layers to the I-type semiconductor layers be reduced, but also the larger band gap width can be obtained, and therefore, the photoelectric conversion efficiency is high.

The invention discloses a flexible composite laminated solar cell and a preparation method thereof. The composite laminated solar cell sequentially comprises a high-wear-resistance light-transmittinglayer, a charge transmission layer, a perovskite cell layer, a hole transmission layer, a gallium arsenide cell layer, a metal electrode layer and a flexible packaging backboard layer from a light receiving surface to a backlight surface. The structure is a thin-layer flexible structure and can be bent, curled and folded; according to the invention, the problems of gallium arsenide energy loss andlattice mismatch are solved, the energy gap is large, the overall conversion efficiency is improved, and the service life is prolonged. According to the invention, the charge transport layer is prepared by adopting a spraying method, the hole transmission layer is prepared by adopting a spray pyrolysis method, the metal electrode layer is prepared by adopting a coating method, and the flexible packaging backboard layer is prepared by adopting a thermal bonding method; the preparation difficulty is reduced while the thin layer preparation requirement is met, industrial popularization is facilitated, layer-to-layer combination is facilitated through selection of the preparation method, and then the conversion efficiency is improved.

The invention discloses a deep ultraviolet LED structure and a manufacturing method thereof. The deep ultraviolet LED structure comprises a deep ultraviolet AlGaN epitaxial structure and an n-type Ga2O3 nano thin film, wherein the deep ultraviolet AlGaN epitaxial structure comprises a p-type AlGaN layer; the n-type Ga2O3 nano thin film is positioned on the upper surface of the deep ultraviolet AlGaN epitaxial structure; the n-type Ga2O3 nano thin film and the p-type AlGaN layer form a tunnel junction, and the tunnel junction is used as a surface electrode contact layer and a hole supply layer.The tunnel junction is formed by using the n-type Ga2O3 nano thin film and the p-type AlGaN layer, on one hand, the tunnel junction is used as a hole supply layer to improve the hole concentration, and on the other hand, the tunnel junction is used as a surface electrode contact layer and forms good ohmic contact with the surface electrode, so that the external quantum efficiency of the deep ultraviolet LED is improved, and meanwhile, the n-type Ga2O3 nano thin film has relatively high transmittance for light in a deep ultraviolet band and does not absorb light generated by the LED.

The invention discloses an Al-doped gallium oxide X-ray detector and a preparation method thereof. The preparation method of the Al-doped gallium oxide X-ray detector comprises the following steps of: providing an Al-doped gallium oxide single crystal; cutting the Al-doped gallium oxide single crystal to obtain a single crystal substrate sheet; carrying out annealing treatment on the single crystal substrate sheet to obtain an annealed single crystal substrate sheet; and forming an interdigital electrode on the annealed single crystal substrate sheet to obtain the Al-doped gallium oxide X-ray detector. According to the method, the Al-doped gallium oxide single crystal is adopted, the resistivity of the detector is improved by doping Al in gallium oxide, the single crystal substrate sheet is obtained after the Al-doped gallium oxide single crystal is cut, the single crystal substrate sheet is subjected to annealing treatment, and the concentration of free electrons in the Al-doped gallium oxide single crystal is reduced through annealing treatment, so that the sensitivity of the detector is improved.

The invention relates to a thin film solar cell and a formation method thereof. The thin film solar cell comprises a substrate, a photoelectric conversion unit, an anti-reflective layer, a positive electrode, and a backplate. The photoelectric conversion unit, which is arranged on the upper surface of the substrate, includes a P type semiconductor layer, an I type semiconductor layer, and an N type semiconductor layer; doped ion concentration in the P type semiconductor layer is successively increased along a direction from a position close to the I type semiconductor layer to a position far from the I type semiconductor layer; and doped ion concentration in the N type semiconductor layer is successively increased along a direction from a position close to the I type semiconductor layer to a position far from the I type semiconductor layer. Besides, the anti-reflective layer is arranged on the upper surface of the photoelectric conversion unit; the positive electrode is arranged on the upper surface of the anti-reflective layer; and the backplate is arranged on the lower surface of the substrate. According to the invention, pollution on an I type semiconductor layer by a P type semiconductor layer or an N type semiconductor layer can be reduced; and a broad band gap can be realized; therefore, photoelectric conversion efficiency is high.

The invention discloses a nitrogen-doped nickel oxide and zinc oxide near ultraviolet detector of the following structure of Ag/NiO:N/ZnO/FTO conductive glass, and FTO represents fluorine doped indiumoxide. According to the detector, the carrier concentration in NiO is improved, the conductivity is increased, a built-in electric field is enhanced, the forbidden band is narrower, absorption wavelength moves towards the long wave direction, and the detector is highly sensitive to weak UVA near ultraviolet.

The invention discloses a mid-far infrared avalanche photodetector which comprises a substrate, a buffer layer, a lower ohmic contact layer, a multiplication layer, a charge layer, a gradient layer, an absorption layer and an upper ohmic contact layer which are sequentially connected from bottom to top, and the doping type of the substrate and the buffer layer is n type. Or the mid-far infrared avalanche photodetector comprises the substrate, the buffer layer, a second ohmic contact layer, the absorption layer, the gradient layer, the charge layer, the multiplication layer and a first ohmic contact layer which are sequentially connected from bottom to top, and the doping type of the substrate and the buffer layer is p type, wherein the multiplication layer is made of an AlAsxSb1-x material, x is greater than or equal to 0.12 and less than or equal to 0.18, the gradient layer is of a plurality of (InAs)m/(AlAs0.15Sb0.85)n quantum well structures or an InyAl1-yAszSb1-z material, and thedetection wavelength of the absorption layer is a middle and far infrared band. The mid-far infrared avalanche photodetector provided by the invention can block dark current and reduce noise, does notneed a cooling device, improves the working temperature of the device, reduces the cost, and is convenient to use.

The invention relates to the technical field of laser chips, in particular to a VCSEL chip with high recombination efficiency and a manufacturing method thereof. The VCSEL chip comprises a substrate,an epitaxial layer and an N-contact, the epitaxial layer comprises an N-DBR, a quantum well, an oxide layer and a P-DBR, the P-DBR, the oxide layer and the quantum well are etched to the surface of the N-DBR to form a table top, the quantum well comprises a plurality of pairs of quantum well composite layers, each quantum well composite layer comprises AlxGaAs potential barriers, InGaAs potentialwells and AlxGaAs potential barriers which are grown in an overlapping mode, the P-DBR is divided into a central area, a middle area and an edge area, the central area is a light outlet hole, a firstSiNx layer grows on the P-DBR at the position corresponding to the central area, a P-contact is evaporated on the P-DBR at the position corresponding to the middle area, and a second SiNx layer growson the P-DBR at the position corresponding to the edge area. The potential barrier in the quantum well in the VCSEL chip has high forbidden bandwidth, lattice matching is easy to achieve, more electrons are intensively bound in the quantum well, excitation probability is increased, composite efficiency is improved, and therefore, stimulated radiation with higher efficiency is achieved.

The invention relates to a defect-state TiO2/Fe3O4 composite nanofiber material and a preparation method thereof, and belongs to the technical field of materials. The preparation method of the material comprises the following steps: firstly, dispersing a titanium source, an iron source and a high-molecular polymer in a solvent to prepare a stable and uniform solution; then preparing the solution into a nanofiber membrane through an electrostatic spinning technology; and calcining the nanofiber membrane, grinding the calcined material and sodium borohydride, and reducing in a nitrogen atmosphere to obtain the defect-state TiO2/Fe3O4 composite nanofiber material. The method is simple to operate, easy to control, environment-friendly and capable of realizing continuous production, and the obtained defect-state TiO2/Fe3O4 composite nanofiber material has good crystallinity and photoresponsiveness and has excellent degradation performance on organic pollutants in a water environment.

The invention discloses a three-negative elastic wave metamaterial with a wide forbidden band. The three-negative elastic wave metamaterial comprises N unit cells, wherein each unit cell is of a two-dimensional structure and is square; a base material is foam; a round hole is formed in the center of the base material; four elliptical holes are formed around the round hole; the four elliptical holes are filled with scatterer metal tungsten, but the elliptical holes cannot be filled with scatterers; and the whole unit cell is of a central symmetry structure. The elastic wave metamaterial can simultaneously achieve equivalent negative mass density, equivalent negative volume modulus and equivalent negative shear modulus within the same frequency range, so that negative refraction of transverse waves and longitudinal waves of elastic waves is achieved within the same frequency range; and meanwhile, the elastic wave metamaterial also has the relatively wide forbidden band. The material canbe used for designing functional devices and gradient materials for regulating and controlling the elastic waves, and can also be used for vibration isolation and sound insulation of mechanical equipment and building structures.

The invention relates to a heterojunction spinning field effect transistor based on a 4H-SiC substrate, and a manufacturing method for the heterojunction spinning field effect transistor. The method comprises the following steps: selecting the 4H-SiC substrate; growing a Ga2O3 epitaxial layer on the surface of the 4H-SiC substrate through employing the MBE technology; forming a source region and a drain region on the Ga2O3 epitaxial layer through the ion implantation technology; respectively forming a source region ohmic contact electrode and a drain region ohmic contact electrode in the resource region and the drain region; growing an oxidation layer on the Ga2O3 epitaxial layer, and carrying out the etching to form a grid region; forming a Schottky contact grid electrode on the surface of the grid region through the technology of magnetron sputtering, and finally forming the heterojunction spinning field effect transistor based on the4H-SiC substrate. According to the invention, the source and drain regions are formed in a mode of selecting regions and carrying out the implantation of Fe ions. The method is compatible with the conventional technology, is simple in manufacturing, is small in surface effect, and can improve the spinning injection and receiving efficiency.