17results about How to "Reduce recombination rate" patented technology

The invention relates to a back contact cell, a preparation method of the back contact cell and a photovoltaic module. The substrate has a first surface including first regions and second regions arranged alternately. The tunneling layer is arranged in the first region, and the first doped semiconductor layer is arranged on the side, away from the substrate, of the tunneling layer. The doped field region is located in the first region, and the doped field region and the first doped semiconductor layer are both provided with first doped elements. The second region is provided with a groove which is recessed relative to the first region, one part of the amorphous layer is arranged on the second region, and the other part of the amorphous layer is arranged on the side, away from the substrate, of the first doped semiconductor layer. The second doped semiconductor layer is arranged on one side, far away from the substrate, of the amorphous layer and is provided with a second doped element which is different from the first doped element in doping type. The depth of the doped field region is smaller than that of the groove. Therefore, the passivation performance of the first region can be improved, the passivation performance of the second region can also be considered, and the passivation performance of the back contact battery can be improved on the whole.

The invention discloses an II-type heterojunction BiOBr / NiV-LDH composite photocatalytic material as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing NiV-LDH powder by adopting a hydrothermal method; the BiOBr / NiV-LDH composite photocatalytic material is further prepared by adopting a sol-gel method; the micro-morphology of the BiOBr / NiV-LDH composite photocatalyst is accurately regulated and controlled to be of an II-type heterojunction nanosheet structure by regulating and controlling key process parameters such as the reaction temperature and the reaction time of a sol-gel method; according to the structure, the specific surface area of the material is greatly increased, and then rich active sites are provided for photocatalytic reaction; in the prepared BiOBr / NiV-LDH composite photocatalytic material, an II-type heterojunction structure formed by BiOBr and NiV-LDH can obviously reduce the recombination rate of photo-induced electron-hole pairs, and the visible light response range of the material is effectively widened; meanwhile, NiV-LDH has excellent photo-generated hole capturing capability, can be used as a cocatalyst for surface oxidation reaction, and synergistically improves the photocatalytic performance, so that the composite material finally shows excellent catalytic activity and stability in the field of pollutant degradation.

The invention relates to a two-dimensional metal material for an ultraviolet photoelectric detector and a preparation method of the two-dimensional metal material, and belongs to the technical field of detector preparation, a sapphire substrate is activated through high-activity particles through plasma treatment, hydroxyl active sites are introduced, a clean interface foundation is laid for heteroepitaxial growth of an ultra-wide forbidden band Ga2O3 film, and the performance of the detector is improved. The method comprises the following steps: performing chemical vapor deposition on Ga2O3 to ensure the specific absorption capacity of Ga2O3 to ultraviolet light, annealing in a mixed atmosphere after chemical vapor deposition, repairing the oxygen vacancy defect of a Ga2O3 film by using the high activity of ozone, improving the crystallization quality, effectively reducing dark current noise, and performing in-situ growth of a WSe2 layer in a high vacuum environment through a pulse laser deposition technology to form a van der Waals heterojunction without lattice mismatch. And an efficient carrier separation channel can be constructed by virtue of energy level matching of WSe2 and Ga2O3, so that the problem that ultraviolet absorption and carrier transmission are difficult to consider by virtue of a single material is solved, and the light response capability of the device is remarkably enhanced.

This application relates to the field of solar cell technology, and more particularly to a solar cell, a tandem cell, and a photovoltaic module. The first textured structure of the metallized region includes a raised structure, which includes at least a platform structure. The platform structure includes a side surface and a top platform with micro-pyramids. Both the side surface and the micro-pyramids reflect incident light, which is beneficial to improving the absorption capacity of long-wavelength light. Furthermore, the combination of the side surface and the micro-pyramids helps to reduce the number of relatively large sharp peaks, reduces surface defects, and facilitates the deposition of a passivation layer, thereby reducing the recombination probability of charge carriers and improving the photoelectric conversion efficiency of the solar cell. At the same time, the top platform with micro-pyramids can also allow the electrode paste to fully fill the gaps, increasing the contact area between the electrode and the substrate, which helps to reduce the contact resistance and improve the charge carrier collection efficiency, thereby improving the photoelectric conversion efficiency.

The application discloses a MOF photocatalyst with a bimetallic UiO-66-NH2 as a carrier loaded with Pt, and the photocatalyst is prepared by a solvothermal method, a modification carrier of UiO-66-NH2 (Zr:Ce=2:1), and a sodium borohydride reduction method for loading Pt. The obtained Pt@UiO-66-NH2 (Zr:Ce=2:1) photocatalyst has a high degradation rate, a high mineralization rate and high stability in a photocatalytic degradation process of toluene, and the preparation method is simple and easy to implement, so that the photocatalyst has a good application prospect in a terminal treatment process of photocatalytic VOCs oxidative degradation.

This invention relates to a method for preparing double perovskite La2CoFeO6 and its application in degrading odorous pollutants, comprising the following steps: dissolving La(NO3)3·6H2O, Co(NO3)2·6H2O, and Fe(NO3)3·9H2O in a mixed solution of deionized water and ethylene glycol or deionized water and citric acid, adjusting the pH, and then mixing thoroughly; placing them separately in a high-pressure reactor and heating or evaporating the moisture and drying in an oven to obtain precursor powder or dry gel; then calcining at high temperature and cooling to obtain double perovskite La2CoFeO6 powder. The R3c phase La2CoFeO6 material provided in this application, by combining crystal structure regulation with oxygen vacancy defect engineering, establishes a synergistic enhancement mechanism of "structure optimization + defect regulation" for double perovskite materials, significantly improving the photoresponse capability and catalytic performance of the material, providing a new technical path and material design idea for the design of subsequent high-performance photocatalysts for odor pollution control.

The invention belongs to the crossing field of a radioactive wastewater treatment technology and a nano environmental catalytic material, and particularly relates to a photocatalytic material based on an eggshell structure biological source carbon dot / ZnCdS heterojunction and application of the photocatalytic material in uranium extraction. According to the material, biological source carbon dots derived from orange peel are used as a shell layer and wrap the surface of polyhedral ZnCdS to form an eggshell structure heterojunction. The preparation method comprises the following steps: performing pyrolysis and hydrothermal treatment on orange peel to prepare carbon dots; the preparation method comprises the following steps: etching a ZIF-8 precursor through tannic acid, and carrying out vulcanization, cadmium doping and hydrothermal reaction to obtain ZnCdS; and finally, compounding the carbon dots with ZnCdS in ethanol. The eggshell structure effectively promotes the separation of photon-generated carriers and enhances the stability of ZnCdS. In an experiment of photocatalytic reduction of uranyl ions, the uranium removal rate of the material reaches 97.6%, and is remarkably improved compared with 72.3% of pure ZnCdS. The material is low in cost, environment-friendly and suitable for radioactive wastewater treatment and uranium extraction from seawater.

This application discloses a method for reducing the efficiency loss during solar cell cutting, relating to the field of solar cell technology. The method includes: providing an N-type silicon wafer; performing boron diffusion on the N-type silicon wafer; removing the PN junction in the laser-cut region of the boron-diffused silicon wafer; growing a tunneling layer on the surface of the N-type silicon wafer; growing a polycrystalline silicon layer on the surface of the tunneling layer; performing phosphorus diffusion on the polycrystalline silicon layer on the back side of the N-type wafer; and removing the PN junction in the laser-cut region of the phosphorus-diffused silicon wafer. The method provided in this application, by removing the PN junction in the laser-cut region in advance after both boron and phosphorus diffusion, can significantly reduce the probability of hole-electron recombination during the cutting process, thereby reducing the efficiency loss during solar cell cutting.

The present disclosure relates to a preparation method of a nano-porous doped bismuth vanadate and a photoactive electrode, and relates to the technical field of doped bismuth vanadate preparation. The method comprises: 1. obtaining a first solution: obtaining a first citric acid solution, adding a bismuth source, a lanthanum source and a molybdenum source to obtain the first solution; the amount of substance of citric acid is N, and the amounts of substance of bismuth element, lanthanum element and molybdenum element are x, y and z respectively, so that N:(x+y+z)=(1.5-4):1; obtaining a second solution: obtaining a second citric acid solution and adding a vanadium source to obtain the second solution; the amount of substance of vanadium element is A, so that x:y:z:A=(6-9):(0.5-2):(0.5-2):10, and x+y+z=A; 2. adding the second solution to the first solution in batches to obtain a third solution; 3. adjusting the pH value of the third solution to 4-8 and drying; calcining the dried product to obtain the nano-porous doped bismuth vanadate.

The invention discloses a hetero-junction catalyst based on halloysite as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic water treatment. According to the preparation method, natural halloysite is taken as a carrier, and a ternary heterojunction with a synergistic effect of BiVO4 and MIL-100 is constructed on the surface of the natural halloysite by virtue of an in-situ loading and hydrothermal compounding process, so that the BiVO4-coated MIL-100-coated HNT heterojunction catalyst is prepared. According to the catalyst, active phase agglomeration is inhibited through a halloysite tubular structure, photon-generated carrier separation is promoted through energy band matching of BiVO4 and MIL-100, and generation of active species is strengthened through Fe < 2 + > / Fe < 3 + > valence cycle of MIL-100; under the synergistic effect of visible light and H2O2, active species such as hydroxyl free radicals are efficiently generated through a photocatalysis-Fenton-like coupling mechanism, and phenol pollutants such as resorcinol and the like and refractory pollutants such as 1H-benzotriazole and polyethylene glycol in photovoltaic wastewater can be rapidly and thoroughly mineralized; the blank of the ternary composite heterojunction catalyst in the field of photovoltaic wastewater treatment is filled, the ternary composite heterojunction catalyst has the characteristics of low cost and environment friendliness, and a feasible technical scheme is provided for green and efficient treatment of photovoltaic wastewater.

The application discloses a graphene short channel preparation method based on lateral etching, which comprises the following steps: firstly, forming a graphene layer and a metal layer on a substrate, and then forming a hard sacrificial mask on the metal layer; then, removing the metal layer outside the hard mask area by a chemical etching method, and etching the metal layer laterally at the edge of the mask area to form a graphene short channel; and finally, depositing metal based on the hard sacrificial mask to form a metal electrode on the other side. The preparation method of the application can obtain a graphene channel length which is not limited by the minimum line width of a patterning process equipment, and the graphene is not in contact with organic contaminants such as photoresist throughout the whole process, so that a higher channel carrier speed and a lower ohmic contact resistance are realized, the types of electrodes on both sides can be independently changed to construct an internal potential field, a high-speed and low-recombination-rate graphene channel is obtained, and then a high-speed photoelectric detector is realized, and the process is easy to control and has an array potential.

The invention discloses a K / FeS / g-C3N4 / TiO2 (at) PVDF membrane for photocatalytic oxidation, a preparation method and application, through SO2 and CO2 generated by pyrolysis of K4 [Fe (CN) 6] and K2SO3, gaps are generated in a microstructure of g-C3N4, the specific surface area is higher, adsorption of organic pollutants is enhanced, the reaction rate is increased, a FeS / g-C3N4 / TiO2 heterojunction structure is constructed, and the photocatalytic oxidation performance of the membrane is improved. And carbon defects or nitrogen defects generated by K ionization are introduced into the structure, so that stable electron channel connection and light energy absorption and conversion paths are realized, the light response efficiency is improved, the recombination rate of photo-generated electron holes is reduced, and the free radical yield is improved. The membrane material is applied to a circulating aquaculture water body treatment system, odor substances are degraded through photocatalytic oxidation, and deep purification of water is achieved.

This invention discloses a rare-earth co-doped TiO2 photocatalyst and its preparation method. The photocatalyst structure includes: a TiO2 crystal matrix, a rare-earth ion doped layer doped within the TiO2 crystal lattice, a transition control layer distributed in the middle region of the TiO2 crystal, a surface-active layer enriched on and near the surface of the TiO2, and a mesoporous structure formed within the TiO2. The rare-earth doped layer in the TiO2 is used to suppress photogenerated electron-hole recombination, the transition control layer is used to regulate carrier migration, the surface-active layer is used to enhance the adsorption and interfacial reaction capabilities of organic pollutants, and the mesoporous structure is used to improve the diffusion efficiency of pollutant molecules. Through a multi-layered synergistic structural design, this invention improves the utilization efficiency of photogenerated carriers while maintaining the ultraviolet photocatalytic ability of TiO2, significantly enhancing the degradation and deodorization performance of organic pollutants.

The invention provides a D-A structure type heterogeneous catalyst COFBTC-PY as well as a preparation method and application thereof, belongs to the technical field of photocatalysts, and can solve the technical problems that a catalyst system applied to benzylamine oxidative coupling generally has relatively low sunlight utilization efficiency and too high photo-induced electron-hole pair recombination rate at present. The invention relates to a D-A structural type heterogeneous catalyst COFBTC-PY, the D-A structural type heterogeneous catalyst COFBTC-PY is constructed by using 1, 3, 6, 8-tetra-(p-aminophenyl)-pyrene and 5, 5 '-(benzo [C] [1, 2, 5] thiadiazole-4, 7-diyl) bis (thiophene-2-formaldehyde) as units, and the D-A structural type heterogeneous catalyst COFBTC-PY has the following structural formula as shown in the specification. The D-A structure type heterogeneous catalyst COFBTC-PY can be used as a photocatalyst to be applied to catalysis of oxidation reaction of benzylamine or derivatives thereof, and has the advantages of high activity, excellent stability, wide spectral response, recyclability and low cost.

The present application relates to the technical field of antifouling functional coating materials, and specifically discloses a composite coating with switchable wettability in response to visible light and a preparation method thereof.The composite coating has an organic-inorganic hybrid multilayer structure, and comprises, from the surface of a substrate outward, a polydimethylsiloxane hydrophobic bottom layer, a ZIF-8 metal organic framework intermediate layer arranged on the surface of the polydimethylsiloxane hydrophobic bottom layer, and a nitrogen-doped titanium dioxide active layer arranged on the surface of the ZIF-8 metal organic framework intermediate layer.The composite coating has the characteristics of efficient response to visible light, reversible switching between superhydrophilicity and oleophobicity, excellent durability, and low-temperature preparation, and can be widely applied to self-cleaning antifouling scenarios to solve the problem of dust deposition, oil stain adhesion and other fouling problems of building exterior walls, photovoltaic panels, vehicle surfaces and other surfaces exposed to atmospheric environments.

The invention discloses a C3N5-C3N4 photocatalytic hydrogen evolution material as well as a preparation method and application thereof. The material consists of a core layer, a shell layer and an interface transition region, wherein the core layer is C3N5 rich in S-O bonds; the core layer is coated with the shell layer, the shell layer is C3N4 with gradient increasing nitrogen vacancy concentration from inside to outside, and CoP nanoparticles are loaded on the surface of the shell layer; and the C / N atomic ratio in the interface transition region is in continuous gradient change to form a built-in electric field gradient. The preparation method comprises the following steps: preparing a C3N5 core layer through pyrolysis of a sulfur-containing precursor; coating a C3N4 precursor on the surface through solvothermal reaction; carrying out heat treatment in a gradient ammonia atmosphere, carrying out synchronous crystallization and introducing gradient nitrogen vacancies; and finally, loading CoP through photodeposition. The material has spatially separated light absorption, charge transfer and reaction centers, shows excellent hydrogen evolution activity and stability under visible light, and is suitable for the field of photocatalytic hydrogen production.