33results about How to "Reduce surface defect density" patented technology

The ternary alloy CdSe_xTe_1-x(2 1 1) and the quaternary alloy Cd_1-zZn_zSe_xTe_1-x have been grown on Si(2 1 1) substrates using molecular beam epitaxy (MBE). The growth of CdSeTe is facilitated using a compound CdTe effusion source and a Se effusion source while the growth of CdZnSeTe is facilitated using a compound CdTe effusion source, a compound ZnTe effusion source, and an elemental Se source. The alloy compositions (x) and (z) of CdSe_xTe_1-x ternary compound and Cd_1-zZn_zSe_xTe_1-x are controlled through the Se/CdTe and ZnTe/CdTe flux ratios. The rate of Se incorporation is higher than the rate of Te incorporation as growth temperature increases. As-grown CdSeTe with 4% Se and CdZnSeTe with 4% Zn+Se, which is substantially lattice matched to long-wavelength infrared HgCdTe materials, exhibits excellent surface morphology, low surface defect density (less than 500 cm²), and a narrow X-ray rocking curve (a full-width at half maximum of 103 arcsec).

The invention discloses a polymer-nanometer metal oxide composite ink. The polymer-nanometer metal oxide composite ink comprises at least one polymer with a fatty amine unit, at least one nano-metal oxide particle and at least one organic alcohol solvent used as a solvent, wherein the polymer is preferably selected from linear or branched polyethylene imine, end position ethoxylated or ethylaminated polyethylene imine, or a polyethylene imine fragment-containing copolymer. The invention also discloses a preparation method of the composite ink. A composite film is produced through spin-coating or printing the composite ink, and can be applied in solar batteries, light emitting diodes and other optoelectronic devices as an electrode modification layer to improve contact performances between the electrode and an organic active layer in order to improve the performances of the optoelectronic devices.

The invention mainly belongs to the field of photoelectrochemistry water-splitting for hydrogen production and particularly relates to a vanadium-doped ZnO nanorod array photo-anode, a preparation method of the vanadium-doped ZnO nanorod array photo-anode and an application of the vanadium-doped ZnO nanorod array photo-anode in photoelectrochemistry water-splitting for hydrogen production. The method comprises the steps of preparing a ZnO seed crystal solution, a vanadium-doped solution and a growth solution correspondingly; conducting spin-coating on conducting glass with the ZnO seed crystal solution and obtaining the conducting glass with the surface covered with a ZnO seed crystal layer after spin-coating and annealing; pulling the conducting glass with the surface covered with the ZnO seed crystal layer into a mixed solution of the vanadium-doped solution and the growth solution for a hydrothermal reaction, washing the conducting glass with deionized water after completion of the reaction, conducting annealing in a muffle furnace and then obtaining an vanadium-doped ZnO nanorod array. By adopting the vanadium-doped ZnO nanorod array photo-anode provided by the invention, the carrier life is prolonged, combination of electron holes is reduced, and the photoelectrochemistry water-splitting performance is improved.

A film 3 of a nitride of a group 13 element is grown on a seed crystal substrate 11 by flux process from a melt containing a flux and a group 13 element under nitrogen containing atmosphere. The film 3 of a nitride of a group 13 element includes an inclusion distributed layer 3a in a region distant from an interface of the film of a nitride of group 13 element on the side of the seed crystal substrate 11 and containing inclusions derived from components of the melt, and an inclusion depleted layer 3b, with the inclusion depleted. provided on the layer 3a.

The invention provides a preparation method of an N-type low-defect silicon carbide epitaxial wafer. The method comprises the steps of preparation of a substrate, online substrate etching, growth of a buffer layer and growth of an epitaxial layer, wherein growth of the epitaxial layer includes growth, etching, blowing and re-growth. The method can be used to effectively reduce the dislocation density of the base, reduce deposit in the cavity, reduce the defect density of the surface of the silicon carbide epitaxial wafer, improve the quality of a silicon carbide epitaxial material, and is wide in application range, low in processing cost and suitable for industrial production.

Disclosed is an epitaxial wafer including a substrate, and an epitaxial structure disposed on the substrate, wherein the epitaxial structure includes a first epitaxial layer, a second epitaxial layer disposed on the first epitaxial layer, and a third epitaxial layer disposed between the first epitaxial layer and the second epitaxial layer, the third epitaxial layer having a first doping concentration around a first boundary adjacent to the first epitaxial layer and a second doping concentration different from the first doping concentration around a second boundary adjacent to the second epitaxial layer.

A film 3 of a nitride of a group 13 element is grown on a seed crystal substrate 11 by flux process from a melt containing a flux and the group 13 element under nitrogen containing atmosphere. The film 3 of the nitride of the group 13 element includes an inclusion distributed layer 3a in a region distant from an interface 11a of the film 3 of the nitride of the group 13 element on the side of the seed crystal substrate 11 and containing inclusions derived from components of the melt, and an inclusion depleted layer 3b, with the inclusion depleted. provided on the layer 3a. Laser light A is irradiated from the side of the back face 1b of the seed crystal substrate 11 to peel the single crystal 3 of the nitride of the group 13 element from the seed crystal substrate 11 by laser lift-off method.

A semiconductor light emitting device includes a film of a nitride of a group 13 element grown on a seed crystal substrate by flux method from a melt including a flux and a group 13 element under nitrogen containing atmosphere, an n-type semiconductor layer provided on the film of the nitride, a light emitting region provided on the n-type semiconductor layer, and a p-type semiconductor layer provided on the light emitting region. The film includes an inclusion distributed layer in a region distant by 50 μm or less from an interface of the film on the side of the seed crystal substrate and including inclusions derived from components of the melt, and an inclusion depleted layer with the inclusion depleted formed on the inclusion distributed layer.

The invention provides a preparation method of a low-defect silicon carbide epitaxial material, which relates to the technical field of silicon carbide epitaxial materials, and comprises the following steps: introducing argon and mixed gas consisting of hydrogen chloride and hydrogen into a reaction chamber to carry out in-situ etching on a silicon carbide off-axis substrate for 5-20 minutes. The introduction of hydrogen chloride and hydrogen enables a Si component and a C component on the surface of the silicon carbide off-axis substrate to reach similar removal speeds, so that a smoother substrate surface is obtained, the introduction of argon enables a temperature field in the reaction chamber to be more uniform, anisotropy generated when the silicon carbide off-axis substrate is etched by hydrogen chloride and hydrogen in the reaction chamber is reduced, and the yield of the silicon carbide off-axis substrate is improved. The non-uniformity of surface etching and the surface defects of the substrate extending to the epitaxial layer are reduced, and the silicon carbide epitaxial material obtained through the growth of the buffer layer and the growth of the epitaxial layer has the advantages of low surface defect density and high uniformity.

The invention relates to a diamond growth method and system with low defects and high light transmittance. A diamond growth method with low defects and high light transmittance, comprising the steps of: feeding oxygen in stages: pretreating the surface of the seed crystal and putting it into a growth chamber, feeding microwaves with a certain power, and then feeding hydrogen and oxygen to the seed crystal Etch the surface for 15‑60min; then, stop feeding oxygen, feed a certain amount of argon, feed carbon source to generate carbon ion clusters, and then grow diamond stably; stop feeding carbon source, feed oxygen every first time Etching for 10-30min; substrate table lifting: while the stable growth, real-time detection of the thickness data of diamond growth, according to the thickness data, the height of the substrate table is controlled, so that the diamond growth surface is always in the best growth position . The present invention provides a low-defect high-transmittance diamond growth method and system. The grown diamond has a layered structure, and the content of oxygen element is periodically distributed as the thickness of the diamond increases.

The invention discloses a perovskite light absorption layer film and a surface defect passivation method thereof. The method comprises the steps of 1, dissolving PbI2, FAI, PbBr2, MABr and CsIb in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide, and preparing a perovskite precursor solution, 2, dissolving pyrrole in an organic solvent to prepare an additive solution, 3, dispensing the perovskite precursor solution on an FTO conductive glass substrate, starting a spin coater, accelerating to a rotating speed of 1000rpm at an acceleration of 1000rpm s<-1> and rotating for 10s, then accelerating to a rotating speed of 5500rpm at an acceleration of 2000rpm s<-1> and rotating for 25s, and preparing a perovskite thin film, quickly dropwise adding the additive solution obtained in the step 2 on the surface of the perovskite thin film 5 seconds before the high-speed rotation is stopped, and drying in an argon atmosphere to obtain the perovskite thin film. A pyrrole additive is introduced to the surface of a perovskite light absorption layer film, so that the surface defect density is reduced, and a hydrophobic layer is formed on the surface.

The invention provides a p-type crystalline silicon solar cell and a preparation method thereof. The p-type crystalline silicon solar cell is characterized in that the back surface of a p-type crystalline silicon substrate is provided with a first oxide layer, a doped p-type silicon-based thin film layer, a second oxide layer and a silicon-based thin film layer which are sequentially stacked so asto form a laminated structure; a back contact window is formed in the laminated structure, and a metal grid line electrode is formed in the back contact window, wherein an ohmic contact is formed between the metal grid line electrode and one or both of the p-type crystalline silicon substrate and the doped p-type silicon-based thin film layer. According to the method, the hole concentration and the transverse transmission performance of the surface of the p-type crystalline silicon substrate can be improved, and recombination and loss of carriers are reduced; and compared with an existing PERC battery (Passivated Emitter and Rear Cell), a passivation emitter back battery), higher open-circuit voltage and photoelectric conversion efficiency can be obtained.

The invention belongs to the technical field of compound semiconductor wafer polishing, and particularly relates to a surface treatment method for a molecular beam epitaxy InAs substrate. The method comprises chemical mechanical polishing and surface vulcanization passivation treatment, and chemical mechanical polishing adopts an alkaline polishing solution containing colloidal silicon dioxide, a weakly alkaline oxidizing agent, organic sodium salt, a pH regulator and water. According to the method, the problems that scratches and particle pollution are easily generated when the InAs substrate which is a soft compound substrate is polished, and the surface is difficult to deoxidize during epitaxial growth are well solved, and the InAs substrate treated by the method can stably grow a high-quality superlattice infrared detector epitaxial wafer.