8results about How to "Reduce grain boundary defects" patented technology

This invention discloses a method for preparing high-purity oxygen-free copper, relating to the field of metallurgical technology. The method includes multi-stage electrolytic refining, gradient-heating vacuum melting, inert gas-protected refining, electron beam melting, hydrogen plasma arc melting, directional solidification, and post-treatment steps. The multi-stage electrolytic refining utilizes a specific component electrolyte and periodically commutated current; vacuum melting is combined with bidirectional electromagnetic stirring; inert gas-protected refining is combined with a gradient reduction composite covering agent; electron beam and hydrogen plasma arc melting achieve deep purification and deoxidation; and directional solidification and two-stage annealing ensure product performance. The high-purity oxygen-free copper prepared by this invention has a conductivity of 102.3% IACS, a copper content ≥99.9999%, and an oxygen content <1.0 ppm. It exhibits high purity, low oxygen content, and excellent conductivity. The process is stable and controllable, making it suitable for high-end electronics applications.

The invention discloses a perovskite solar cell and a preparation method thereof, a laminated solar cell, a cell module and an electric device. The perovskite solar cell comprises a perovskite active layer, and the perovskite active layer comprises a perovskite structure substance and alkali metal fluorate. The perovskite active layer in the perovskite solar cell is doped with alkali metal fluorate, so that directional growth of perovskite grains can be effectively promoted, grain boundary defects of the perovskite active layer are reduced, bulk phase defects are passivated, non-radiative recombination of the perovskite active layer is reduced, and the photoelectric conversion efficiency of the perovskite solar cell is obviously improved. And moreover, a lattice structure can be effectively strengthened, material decomposition is inhibited, lattice vacancies are filled, external erosion is blocked, and ion migration is inhibited, so that the long-term stability of the perovskite solar cell is obviously improved. The laminated solar cell, the cell assembly and the electric device all comprise perovskite solar cells.

The invention discloses a zirconia ceramic matrix with high thermal shock resistance as well as a preparation method and application thereof. The zirconia ceramic matrix comprises a matrix and a coating layer a; the matrix comprises the following components: 90-98 wt% of zirconium oxide; 1.5 to 8 wt.% of a stabilizing agent; % of a grain boundary regulating agent; the stabilizing agent is prepared from the following components in percentage by weight: 2.0 to 4.0 percent of Sc2O3, 0.5 to 1.5 percent of Yb2O3 and 0.3 to 1.0 percent of Er2O3; the grain boundary regulating agent is a composition of a boron source and an aluminum source; in the coating layer a, the molar ratio of zirconium to aluminum is (2-3): 1; and the component 1 is polyvinyl alcohol or polyvinylpyrrolidone. The fracture toughness, bending strength and thermal shock resistance of the ceramic matrix are effectively improved, and the overall mechanical property is remarkably improved. When the material bears thermal shock, the thermal shock resistance of the material is improved, and the application scene of the zirconia ceramic material is expanded.

The application relates to the technical field of lithium ion batteries, and discloses a positive electrode active material, a preparation method thereof and a lithium ion battery. The positive electrode active material comprises first particles, second particles, an inorganic modified phase and a carbon layer; the median particle size D50 of the first particles is 1.0 mu m-5.0 mu m; the median particle size D50 of the second particles is 20 nm-500 nm, and the second particles are distributed on the surface of the first particles and in the gap regions between adjacent first particles; the inorganic modified phase is dispersedly combined on at least part of the surfaces of the first particles and / or the second particles; the carbon layer coats the first particles; and the second particles partially expose the carbon layer. According to the application, the second particles are satellite-distributed on the surface of the first particles, so that the volume energy density can be improved without losing the rate performance, and the battery performance is improved.

The present application belongs to the field of molecular sieve membrane repair, and particularly relates to a method for repairing a molecular sieve membrane. The method uses NO2 and SO2 to repair the molecular sieve membrane. NO2 molecules are prone to dimerization to form N2O4 under certain conditions (low temperature or high pressure), and N2O4 can react with SO2 to form a complex ONONO-SO3, which can form strong affinity with the hydroxyl group exposed at the defect site of the molecular sieve membrane, thereby plugging the molecular sieve membrane channel and repairing the molecular sieve membrane. For small-pore molecular sieve membranes such as six-membered ring or eight-membered ring, N2O4 has a kinetic diameter greater than the pore diameter of the molecular sieve membrane, so it cannot enter the molecular sieve membrane channel and cause channel plugging. For ten-membered ring or twelve-membered ring molecular sieve membranes with larger pore diameters, the adsorption of the ONONO-SO3 complex is not strong due to the larger pore diameter of the molecular sieve membrane, and selective heating desorption can be selected, so the channel will not be permanently plugged.

This invention discloses a titanium oxide-zirconia composite target, its preparation method, and its applications. The titanium oxide-zirconia composite target comprises the following raw materials in parts by weight: 60-80 parts titanium oxide; 20-40 parts zirconium oxide; and 0.5-3 parts cerium oxide or 0.1-1 parts tantalum oxide. By doping titanium oxide and zirconium oxide with specific amounts of cerium oxide or tantalum oxide, this invention effectively improves the grain size of the titanium oxide-zirconia composite target and reduces grain boundary defects. The oxide film obtained from the titanium oxide-zirconia composite target of this invention possesses high refractive index and a wide bandgap, with the bandgap increased to over 3.5 eV, expanding its application in deep ultraviolet optical devices. The doping of cerium oxide or tantalum oxide improves the crack resistance of the film, making it crack-free after bending.

The invention discloses an organic semiconductor material, a preparation method, application and a perovskite solar cell, and belongs to the technical field of organic semiconductor materials and solar cells. An organic semiconductor material having a specially designed structure is provided. By introducing the rigid side arm structure, the conjugate length of the core unit is effectively prolonged, and the carrier transport capability of the hole transport material can be effectively enhanced; particularly, heteroatoms such as oxygen, sulfur and selenium contained in the rigid side arm structure can form a coordination effect with lead atoms in the perovskite, so that multiple effects of passivating defects, namely assisting the crystallization of the perovskite material and the like are achieved; when the perovskite solar cell is prepared, the rigid structure may slow down the aggregation of molecules in a solution and the diffusion rate on a substrate, so that the crystallization process is more uniformly regulated and controlled, the formation of a large-area, high-quality and low-defect-density perovskite thin film is facilitated, pinhole and grain boundary defects are reduced, and the performance of the perovskite solar cell is improved.

The invention belongs to the technical field of perovskite solar cell preparation, and discloses a preparation method of a perovskite precursor solution, a perovskite light absorption layer and a perovskite solar cell based on a non-halogen lead source. A preparation method of a perovskite precursor solution based on a non-halogen lead source comprises the following steps: dissolving the non-halogen lead source, an organic halide AX and an organic acid in a mixed solvent, and continuously stirring at 50-70 DEG C until a solid is completely dissolved to obtain the perovskite precursor solution. According to the invention, organic acid is introduced as an additive to regulate and control crystal growth kinetics, so that the thin film can form a compact and continuous film layer more easily, and the problems of insufficient coverage rate, increased holes and the like are greatly improved; according to the method, the high-quality thin film can be stably prepared under the high-humidity air condition, dependence on the inert atmosphere is not needed, the process complexity and the production cost are greatly reduced, meanwhile, the photoelectric conversion efficiency of a device is improved, the environmental tolerance of the device is enhanced, and the good long-term stability of the device is still kept under the action of air humidity.