41results about How to "Reduced compound center" patented technology

The invention discloses a manufacturing method of an N type all-aluminum back emitter solar cell and a solar cell prepared by the same. The manufacturing method comprises: providing an N type semiconductor substrate, removing a surface damage layer, and preparing a surface pile face; carrying out phosphorus diffusion to form an n<+> doping layer and etching and removing the parts, formed at the edge and the back, of the n<+> doping layer; preparing an antireflection layer at the front side; printing a back aluminium paste and carrying out sintering to form a full-area aluminum back emitter; carrying out etching at the back and removing the aluminium paste and keeping the aluminum back emitter; preparing a back passivation layer at the back; printing a front electrode silver paste and carrying out drying, printing a back electrode silver-aluminium paste and carrying out drying, and carrying out sintering to form electrode ohmic contact. According to the invention, a problem of leak current existence at the boundary of the local back aluminium emitter and the back silver electrode can be solved; the solar cell quality is improved; and the conversion efficiency is improved by increasing the effective area of the PN node. With the back passivation layer, the open-circuit voltage and short-circuit current of the cell are increased. Moreover, the dual-face solar cell can be manufactured, so that the cell energy output is enhanced and the conversion efficiency is improved.

The invention provides a heat treatment method for an n-type silicon wafer. The heat treatment method at least includes the steps that the n-type silicon wafer to be treated is provided, the n-type silicon wafer is put into a heat treatment furnace with a certain temperature, and the temperature is increased to a certain value; oxygen is introduced into the heat treatment furnace; a dispersing agent containing n-type doping elements is supplied to the surface of the n-type silicon wafer so that a silicon oxide layer and an n-type doping layer can be formed on the surface of the n-type silicon wafer; the silicon oxide layer and the n-type doping layer are removed after heat treatment is completed. After the n-type silicon wafer is subjected to heat treatment, recombination centers, caused by the concentration of the doping elements and heat stress, in the n-type silicon wafer can be reduced, the quality and uniformity of the n-type silicon wafer can be improved, the service life of current carriers in the n-type silicon wafer can be prolonged, and thus the conversion efficiency of a solar cell can be improved.

The present invention provides a solar cell and a preparation method thereof, and relates to the technology field of solar cells. The solar cell comprises a cell matrix, a passivating film and a backelectrode. The passivating film is located between the cell matrix and the back electrode, the passivating film is provided with an opening area, and the opening area is internally provided with a high-work-function semiconductor material layer which is located between the cell matrix and the back electrode. The solar cell is employed to relieve the technical problem that there is a high recombination region in a local contact solar cell to cause decreasing of the cell performances in the prior art and achieve the technical effects on reduction of the cell recombination region and improvementof the cell electrical performances in the prior art.

The invention provides a graphene / gallium arsenide solar cell preparation method. The graphene / gallium arsenide solar cell preparation method comprises the following steps of: 1) preparing a window layer on the surface of a gallium arsenide epitaxial wafer and then preparing a heavily-doped gallium arsenide cap layer on the surface of the window layer; 2) preparing a positive electrode on the surface of the heavily-doped gallium arsenide cap layer, and preparing a negative electrode on the surface of the gallium arsenide epitaxial wafer away from the window layer; 3) etching the heavily-doped gallium arsenide cap layer between positive electrode grid lines by the chemical etching method so as to expose the window layer; 4) preparing a graphene layer on the surface of the exposed window layer; 5) preparing an anti-reflection layer on the surface of the graphene layer to obtain a graphene / gallium arsenide solar cell. In the invention, graphene is applied to the gallium arsenide solar cell as a transparent conductive material, so the conversion efficiency of the gallium arsenide solar cells is further improved and is much higher than that of graphene / gallium arsenide Schottky junction solar cells. In addition, the cost for solar cell preparation is low and the process is simple, which is conducive to industrialization application.

The invention discloses a method for preparing the back surface of a PERC single crystal double-sided solar cell, comprising the following steps: S1, depositing a passivation layer on the back surface of a silicon substrate; S2, using a low-energy laser to irradiate the passivation layer with laser light, so that the laser irradiates the passivation layer with laser light. The lower passivation layer forms a groove, and the silicon substrate in the groove is exposed; S3, deposit a protective layer on the surface of the groove and the passivation layer, and the protective layer is a silicon nitride film; S4, use electronic paste to burn through the groove The protective layer is prepared, and the back electrode is in contact with the silicon substrate in the groove. In the method for preparing the back of the PERC single crystal double-sided solar cell, immediately after depositing the passivation layer, a low-energy laser is used for grooving, which reduces damage to the silicon substrate and reduces energy consumption, and then deposits a protective layer, which not only realizes the protection of the passivation layer It also has a repairing effect on the surface of the silicon substrate and in the body, reducing the recombination center and improving the conversion efficiency of the battery.

The invention provides a texturing technology of a diamond wire solar battery piece. The texturing technology solves technical problems that an antireflection effect of the existing conventional chemical method is not remarkable, cost of matching of whole technology of a black silicon technology is increased more than ten times, the existing diffusion technology is not matched with a polycrystalline diamond wire texturing technology, and so on. The texturing technology of the diamond wire solar battery piece comprises the following steps: a, texturing; b, washing a surface of a silicon wafer with ultrapure water; c, alkaline washing; d, washing the surface of the silicon wafer with the ultrapure water; e, washing with mixed acid solution of hydrofluoric acid and hydrochloric acid; f, washing with the ultrapure water and drying. The texturing technology of the diamond wire solar battery piece, provided by the invention, has the advantage of low reflectivity of polycrystalline.

The invention provides a method for gettering phosphorus in an N-type polysilicon slice by a metallurgical method, and relates to polysilicon. The method is good in gettering effect, low in cost and simple in operation, and is suitable for industrial production. The method for gettering phosphorus in the N-type polysilicon slice by the metallurgical method comprises the following steps of: washing and drying the N-type polysilicon slice; feeding a gas into the obtained polysilicon slice at the temperature of 700 to 1,200 DEG C, performing phosphorous diffusion gettering thermal treatment, andcooling the polysilicon slice; immersing the obtained polysilicon slice into hydrogen fluoride (HF) solution; and corroding a gettering layer on the polysilicon slice by using acid corrosive liquid, washing and drying, and baking so as to obtain the phosphorous-gettered polysilicon slice.

The invention relates to the field of catalysts, in particular to a photocatalyst and a preparation method and application thereof. The photocatalyst is formed by loading protonated crystal g-C3N4 on acidified carbon nanofibers in an electrostatic self-assembly manner, and the loading capacity of the acidified carbon nanofibers is 0.5-5%. The protonated crystal g-C3N4 can effectively reduce the recombination center of carriers, improve the interface transfer of charges and increase active sites of reaction, the acidified carbon nanofibers can improve the transfer of the carriers and can effectively avoid agglomeration of the one-dimensional nanorod structure of the crystal g-C3N4, and under light illumination, the one-dimensional nanorod structure of the crystal g-C3N4 can be converted into the one-dimensional nanorod structure of the crystal g-C3N4. Electrons and electron hole pairs excited from a valence band to a conduction band are firstly generated in g-C3N4, and the electrons can be transferred from the g-C3N4 to the carbon fiber and stored due to excellent conductivity and charge storage capability of the carbon fiber, so that the catalyst has relatively high catalytic activity.

The invention provides a preparing method of a graphene / gallium arsenide solar battery. The preparing method comprises the steps of 1, transferring the graphene to the surface of a window layer of the surface of a gallium arsenide epitaxial wafer to form a graphene layer; 2, preparing a heavy doping gallium arsenide cap layer on the surface of the graphene layer; 3, preparing a rear electrode on the surface of the heavy doping gallium arsenide cap layer, and preparing a front electrode on the heavy doping surface of the gallium arsenide cap layer; 4, adopting a chemical etching method to etch the heavy doping gallium arsenide cap layer among grid lines of the front electrode to expose the graphene layer, and preparing an antireflection layer on the exposed graphene layer. According to the graphene / gallium arsenide solar battery, the graphene layer is adopted as a transparent conducting layer, single or more layer of graphene are transferred to a position between a window layer of a traditional unijunction or multijunction gallium arsenide solar battery and the heavy doping gallium arsenide cap layer through a graphene transferring technology, therefore, transverse transport of photo-generated carriers can be promoted, recombination centers of photo-generated carriers can be reduced, series resistance can be reduced, a fill factor can be improved, and photoelectric conversion efficiency of the solar battery can be improved.

The invention discloses a nonpolar self-supporting GaN-based pin ultraviolet photodetector and a preparation method thereof. The detector comprises a nonpolar self-supporting GaN substrate, an n-type GaN layer, an n-type Al x1 Ga 1‑x1 N graded layer, intrinsic Al x2 Ga 1‑x2 N layer, p-type Al y1 Ga 1‑y1 N / Al y2 Ga 1‑y2 The N superlattice layer and the p-type GaN capping layer are arranged sequentially from bottom to top; the back of the non-polar self-supporting GaN substrate is connected to the n-type ohmic electrode; the upper surface of the p-type GaN capping layer is connected to the p-type ohmic electrode . The detector solves the problems of large polarization electric field, lattice mismatch between the epitaxial layer and the substrate, difficult p-type doping, and uneven internal electric field, and simplifies the preparation process of the ultraviolet photodetector chip.