35results about How to "Good thickness controllability" patented technology

The invention provides a carbon fiber felt reinforcement inorganic polymer matrix composite and a preparation method of the carbon fiber felt reinforcement inorganic polymer matrix composite, and relates to an inorganic polymer matrix composite and a preparation method of the inorganic polymer matrix composite, in particular to the carbon fiber felt reinforcement inorganic polymer matrix composite and a preparation method of the carbon fiber felt reinforcement inorganic polymer matrix composite. The problems that an existing inorganic polymer material is poor in mechanical performance and low in toughness and the operation for adding short carbon fiber is complex are solved. The product is prepared through inorganic polymer material pulp and carbon fiber felt. The inorganic polymer material pulp is prepared through potassium hydroxide, silica sol and aluminosilicate powder. The method includes the steps of firstly, preparing the inorganic polymer material pulp; secondly, washing the carbon fiber felt; thirdly, preparing a prefabricated material blank; fourthly, preparing the carbon fiber felt reinforcement inorganic polymer matrix composite. The method is simple in process, low in cost, environmentally friendly and capable of being use for large-area preparation, and the prepared composite is good in mechanical property and wider in application range.

A F-P pressure sensor with a composite dielectric film disclosed by the present invention comprises an upper ferrule with a F-P resonant cavity, a lower ferrule which is axially fixedly connected with the upper ferrule and inserted into the lower ferrule. A ferrule for the fiber, and a pressure diaphragm covering the port of the F‑P resonator. At least one layer of composite dielectric film is grown on the back side of the pressure diaphragm and the silicon wafer at the bottom of the groove of the F-P resonator, and the composite dielectric film is SiO 2 / Ta 2 o 5 Thin film, Si 3 N 4 / Ta 2 o 5 thin film or SiO 2 / Ta 2 o 5 / Si 3 N 4 A multilayer film in at least one combination form. The invention has the advantages of simple structure, convenient and quick manufacture, low cost and high thermal stability. In the present invention, a composite dielectric film is grown on the back of the pressure diaphragm and the bottom surface of the upper ferrule groove, and the F-P resonant cavity is formed by connecting the pressure diaphragm with the upper ferrule to match the reflectivity of the system. This combined composite dielectric film is not only thermally stable At the same time, it can be combined according to the design requirements to obtain the reflectivity that meets the system requirements.

The invention relates to a preparation method of a GaN epitaxial structure taking a hexagonal BN-graphene composite layer as a buffer layer, and belongs to the technical field of photoelectron. The method comprises the steps of polishing and cleaning a copper substrate; growing an h-BN-graphene composite layer on the copper substrate; growing an AlN layer on the h-BN-graphene composite layer by anatomic layer deposition method; and growing a GaN layer on the AIN thin layer by a metal organic matter chemical vapor deposition method. The h-BN-graphene composite layer is used as the buffer layerbetween the copper substrate and the GaN epitaxial layer, thus, the problems of defect dislocation, crack and the like caused by lattice mismatching and thermal mismatching between the substrate andthe epitaxial layer can be solved, the stress between the substrate and an epitaxial material is effectively reduced, and the quality of the GaN epitaxial layer is improved.

The invention provides a bulk effect solar cell material which comprise a metal electrode, BiFeO3 ferroelectrics and a LaNiO3 / Si substrate, wherein the BiFeO3 ferroelectrics grows vertical to the direction of the LaNiO3 / Si substrate. The invention also provides a preparation method of the bulk effect solar cell material. The method comprises the following steps of: with BiFeO3 as structural material, preparing pure phase BiFeO3 film by using a sol-gel method, spin-coating the obtained BiFeO3 film on the LaNiO3 / Si substrate and carrying out stepped annealing at a high temperature, and finally sputtering electrodes to the BiFeO3 film. The BiFeO3 film disclosed by the invention has uniform and dense surface, good crystalline properties and no impurity phase, and can test photovoltaic effect by using a metal electrode-ferroelectric-buffer layer substrate sandwich structure. The test structure is simple and clear and larger open-circuit voltage can be obtained.

The invention relates to a production method of nitride epitaxial wafers and a gallium nitride laser device. The method comprises the following steps that 1, a copper substrate is polished and cleaned; 2, a graphene layer grows on the copper substrate; 3, the graphene layer growing on the copper substrate is transferred to target substrates; 4, an aluminum nitride thin layer grows on the graphene layer through an atomic layer deposition method; and 5, a GaN layer grows on the aluminum nitride thin layer through a metal organic matter chemical vapor deposition method. By means of the method, the nitride epitaxial wafers can grow on the different target substrates, the epitaxial wafers are transferred through the copper substrate, and therefore graphene is transferred to the different target substrates. The graphene layer is used as a buffer layer between the substrate and the GaN epitaxial layer, and the aluminum nitride layer is prepared through the atomic layer deposition method. Layer-by-layer growth of material atomic layers, good thickness controllability and high-precision film growth quality can be achieved, the large lattice mismatch problem between the substrate and the epitaxial layer is solved, the epitaxial layer quality is improved, and high-quality gallium nitride laser device can be obtained.