273 results about "Silicon solar cell" patented technology

The invention relates to the technical field of crystalline silicon solar cells, and particularly discloses a low parasitic absorption TOPCon solar cell which comprises an N-type silicon substrate, a boron emitter is arranged on the front surface of the N-type silicon substrate, a front passivation layer and an antireflection layer are arranged on the side face of the boron emitter, and a tunneling oxide layer is arranged on the back surface of the N-type silicon substrate. Hydrogenated lightly-doped polycrystalline silicon and hydrogenated heavily-doped polycrystalline silicon are arranged on the side surface of the tunneling oxide layer, and conductive oxide is arranged between the hydrogenated lightly-doped polycrystalline silicon and the hydrogenated heavily-doped polycrystalline silicon. According to the low parasitic absorption TOPCon solar cell provided by the invention, on the basis of a TOPCon cell, the thickened fluorine-doped tin oxide is used as the second conductive oxide layer by utilizing the transparent and conductive characteristics of the fluorine-doped tin oxide. Inward diffusion of phosphorus atoms can be effectively prevented during annealing, and inward diffusion of metal Ag can be limited during sintering. Thus, the thinned outer layer hydrogenated heavily doped Poly-Si is configured through the thickened fluorine-doped tin oxide, so that parasitic absorption is reduced.

A back contact solar cell, a preparation method and a battery assembly, which belong to the technical field of crystalline silicon solar cells. The back contact solar cell comprises: a semiconductor substrate, the back surface of which includes first polarity regions and second polarity regions alternately arranged in a first direction; a first functional layer, which is disposed in the first polarity regions; a second functional layer, which is disposed in the second polarity regions; a laser protection layer, which is disposed on the side of the second functional layer away from the semiconductor substrate and exposes electrode contact regions of the second functional layer, wherein the material of the laser protection layer includes laser absorption material; first electrode structures, which are disposed on the side of the first functional layer away from the semiconductor substrate; and second electrode structures, which are disposed on the side of the second functional layer away from the semiconductor substrate and located in the electrode contact regions.

The invention discloses conductive paste, a conductive electrode, a preparation method of the conductive electrode and a crystalline silicon solar cell, and belongs to the technical field of photovoltaic cells, the conductive paste comprises glass powder, silver, nickel and an organic carrier, the glass powder comprises B2O3, corrosive oxide and non-corrosive oxide, and the nickel is added to replace part of silver, so that the usage amount of silver in the conductive paste is reduced, and the cost is reduced. In addition, the molar ratio range of the corrosive oxide and the non-corrosive oxide in the glass powder is limited to be 0.7-2.6. The first passivation layer arranged on the boron diffusion emitter is opened during high-temperature sintering, and the oxidability and the flowability of the glass powder can be balanced to inhibit or delay the formation of an oxidized nickel shell on the surface of the nickel powder, so that a laser enhanced contact post-treatment process is matched; and the photoelectric conversion efficiency of the crystalline silicon solar cell is ensured.

The invention discloses a conductive electrode, a preparation method thereof and a crystalline silicon solar cell, and belongs to the technical field of photovoltaic cells, the conductive electrode comprises a semiconductor base material and a first conductive structure, the semiconductor base material comprises a substrate, a tunneling layer, an n-doped polycrystalline silicon layer and a first passivation layer; the first conductive structure is arranged on the first passivation layer, penetrates through the first passivation layer and is electrically connected with the n-doped polycrystalline silicon layer; wherein the first conductive structure comprises conductive metal, the conductive metal comprises silver, and at least part of the conductive metal penetrates through the first passivation layer and is in electric contact with the face, facing the first passivation layer, of the n-doped polycrystalline silicon layer; and the n-doped polycrystalline silicon layer does not contain silver crystals. Therefore, silver crystals cannot grow into the n-doped polycrystalline silicon layer while the first conductive structure forms ohmic electrical contact with the n-doped polycrystalline silicon layer through the conductive metal, damage to the n-doped polycrystalline silicon layer is effectively reduced, the recombination loss is further reduced, and the photoelectric conversion efficiency of the crystalline silicon solar cell is ensured.

The invention discloses a double-sided flexible solar cell and a preparation method thereof. The solar cell sequentially comprises a flexible semitransparent photovoltaic cell, a curved surface reflector and a flexible photovoltaic cell from top to bottom, wherein the flexible semitransparent photovoltaic cell sequentially comprises a packaging layer, a second transparent electrode, an electron transport layer, a light absorption layer, a hole transport layer and a first transparent electrode from top to bottom; the curved-surface reflecting mirror comprises a curved-surface substrate, a high-reflectivity metal layer and a weather-resistant protective layer from top to bottom in sequence. The flexible photovoltaic cell is one of a perovskite solar cell, an organic solar cell, a CIGS solar cell, a dye-sensitized solar cell, a monocrystalline silicon solar cell, an amorphous silicon solar cell, a cadmium telluride thin film solar cell and a quantum dot solar cell. The double-sided flexible solar cell provided by the invention can solve a series of problems that a traditional flexible solar cell is low in solar spectrum utilization rate, insufficient in photovoltaic and photo-thermal system collaboration, poor in complex curved surface adaptability and the like.

The invention discloses conductive paste, a crystalline silicon solar cell and a preparation method of the crystalline silicon solar cell, and belongs to the technical field of photovoltaic cells. The conductive paste comprises glass powder which accounts for 1.5 wt%-6 wt% of total solids in the conductive paste; an organic carrier accounting for 9 wt% to 15 wt% of total solids in the conductive paste; a first conductive metal, which accounts for 70 wt% to 88 wt% of total solids in the conductive paste; a second conductive metal which accounts for 1 wt% to 10 wt% of the total solid content in the conductive paste; wherein the specific surface area of the second conductive metal is larger than 0.5 m < 2 > / g and smaller than 1.8 m < 2 > / g, and the second conductive metal is selected from nickel or nickel alloy. The nickel or the nickel alloy with the specific surface area is adopted to replace part of silver, the influence on the density of a sintered silver structure and the conductivity of a silver / nickel electrode can be reduced, the photoelectric conversion efficiency of the solar cell can be maintained by adding the nickel powder, and the preparation cost of the solar cell can be reduced by reducing the use amount of the silver.

The invention belongs to the field of precious metal recovery, and particularly relates to a method for leaching silver from a silver-containing retired crystalline silicon solar cell. According to the method, the silver in the silver-containing decommissioned crystalline silicon solar cell is recycled and leached through the synergistic effect of an HNO3-H2O2-Fe < 3 + > composite leaching agent and ionic liquid, and the ionic liquid is prepared from choline chloride and malonic acid. Meanwhile, the leaching rate of silver is further improved by optimizing experimental parameters such as the reaction temperature, the reaction time and the H2O2 supply frequency in the three-section gradient temperature control leaching reaction. Compared with the traditional technology, the method disclosed by the invention is green and environment-friendly, low in cost, small in acid consumption and high in recovery rate.

The invention discloses conductive silver paste for a solar cell and application of the conductive silver paste, and belongs to the technical field of conductive silver paste. According to the invention, the prepared silver paste is printed on a silicon wafer cell in a silk-screen printing manner, so that the good rheological property of printing can be obtained. And a rheometer is introduced for testing, and an SEM scanning electron microscope is introduced for checking the surface appearance of the silver grid line. The invention discloses a TOPCon silicon wafer for a silicon solar cell, which comprises the following components in percentage by weight: 82-90% of silver powder, 20-30% of glass powder and 20-30% of organic carrier. 2-5% of glass powder; and 8-13% of an organic carrier. The conductive silver paste with good rheological property is prepared by using a mixture of polyamide wax and hydrogenated castor oil in a mass ratio of 1: 1 as a thixotropic agent. The main grid silver paste for the silicon solar cell provided by the invention can be well matched with step-by-step printing of a cell piece, different proportions of the binder and the thixotropic agent are used, the photoelectric conversion efficiency is high, the peeling strength of the main grid is high, and the step-by-step printing main grid paste requirements of current different types of paste and cell pieces can be well met.

The invention provides a crystalline silicon solar cell and a perovskite / crystalline silicon laminated solar cell, and belongs to the technical field of solar cells. The crystalline silicon solar cell comprises a cell body, the surface of the cell body is provided with a suede structure, the suede structure comprises a plurality of first pyramids, and each first pyramid comprises a first tower bottom and a first tower top which are arranged in the direction away from the surface of the cell body; and gaps exist between the first tower bottom boundaries of at least part of adjacent first pyramids in the plurality of first pyramids. The crystalline silicon solar cell or the perovskite / crystalline silicon laminated solar cell is based on the improvement of the textured structure, has better light utilization rate and passivation effect, and is beneficial to improving the cell performance.

The present invention belongs to the field of conductive pastes, and discloses a silver-coated nickel paste, a preparation method thereof, and a method for metallizing a high-temperature sintered crystalline silicon solar cell. In the silver-coated nickel paste, the conductive powder accounts for 80-95% by mass of the paste, and the components are silver-coated nickel powder and micron silver powder; the glass powder is 1-6%; the organic resin is 0.1-3%; the thixotropic agent is 0.5-0.8%; other additives are 0-1% and the balance is solvent. Among them, the conductive powder is a mixture of silver-coated nickel powder and silver powder with a mass ratio of 1:(0-50); the resistivity of the used silver-coated nickel powder is ≤96 μΩ·cm, the oxidation-resistant resistivity is ≤205 μΩ·cm, and the titrated nickel content is ≤0.01 mol / L; when using this silver-coated nickel paste to single-backprint crystalline silicon solar cell wafers, compared with pure silver paste, the line resistance is slightly higher, the contact resistance is basically the same, and the printing wet weight is basically the same. After adjustment, the efficiency is 0% to 2% lower than that of pure silver paste, and it can be used to replace the silver paste of crystalline silicon solar cells with pure silver powder. The present invention correspondingly discloses a preparation method of the silver-coated nickel paste and a method for metallizing a high-temperature sintered crystalline silicon solar cell.

A conductive multilayer stack or a conductive multilayer line useful as a metallization layer in photovoltaics as well as other devices; solar cells having a conductive multilayer stack or line; solar modules having such cells; and methods of forming a conductive multilayer stack or line. The conductive multilayer stack or line having a metal layer including copper (Cu) or coated aluminum; a silver contact layer; and a solderable layer between, and contacting, the metal layer and the silver contact layer.

The embodiment of the invention relates to the photovoltaic field, and provides a cyanide-free electroplating silver-coated copper conductive material, a preparation method thereof and a crystalline silicon solar cell. The silver-coated copper electrode provided by the embodiment of the invention comprises a copper core and a copper-tin alloy electroplated layer coated on the surface of the copper core, the surface of the pre-plating material is coated with the silver electroplating layer; the surface of the silver-coated copper material is coated with the self-repairing layer; wherein the self-repairing layer comprises a resin film and a pH response type microcapsule, the microcapsule is embedded in the resin film, and the microcapsule is filled with an ammonium molybdate corrosion inhibitor. The copper-silver interface bonding force can be improved through the copper-tin alloy electroplated layer, and the silver layer material does not contain cyanogen and is environmentally friendly; the corrosion inhibitor in the pH response type microcapsule in the self-repairing film layer on the surface of the silver layer is released under a specific pH condition to form a protection film on the silver layer again, so that the self-repairing purpose is achieved, and the dynamic protection effect is achieved.

The invention provides a tin electroplating solution, a preparation method thereof and a preparation method of a crystalline silicon solar cell, and particularly relates to the technical field of solar cell preparation. The tin electroplating liquid comprises tin methanesulfonate, methanesulfonic acid, a brightener, a stabilizer, a grain refiner, a defoaming agent and water. In the tin electroplating solution, the stabilizer ensures the chemical stability of the tin electroplating solution in long-term use and storage; the microstructure of the coating is further optimized through the synergistic effect of the grain refiner and the defoaming agent; tin methanesulfonate is used as a main salt to provide a high-purity tin source, and the high efficiency and controllability of electroplating reaction are ensured by combining with a strong acid environment of methanesulfonic acid; and the metallic luster and the surface flatness of the plating layer are further enhanced by introducing the brightening agent. The tin electroplating liquid system shows remarkable advantages in the aspects of stability, plating quality and process applicability through cooperation of the raw materials, and the electroplating quality of a tin layer is improved.

The invention relates to the field of silicon solar cells, and particularly discloses a back contact cell module and a photovoltaic system. The battery string comprises a first battery string and a second battery string which are adjacently arranged; the first battery string comprises a first end part battery piece and a first edge welding strip, and the second battery string comprises a second end part battery piece, a second edge welding strip and a first secondary edge welding strip; the first edge welding strip and the first secondary edge welding strip are electrically connected with the bus bar respectively; the back contact battery assembly satisfies the following relation: 1.2 (M + N) < L < 2 (M + N); l is the distance between the first edge welding strip and the first secondary edge welding strip, M is the distance between the second edge welding strip and the first secondary edge welding strip, and N is the distance between the second edge welding strip and the edge of the second end battery piece. By implementing the invention, the capacity and yield of equipment can be improved, pseudo soldering is avoided, and the reliability of the assembly is improved.

The invention discloses a solar cell performance simulation method based on FDTD (Frequency Division Time Division) solution, which comprises the following steps of: 1, looking up optical parameters of materials in a solar cell, and inputting the optical parameters into a material library; 2, establishing an optical model of the solar cell; 3, setting a simulation area and positions and types of refraction and reflection monitors; light intensity and wavelength of an incident source are set according to sunlight; 4, setting applied boundary conditions, and setting grid precision; 5, establishing a complete solar cell optical model; step 6, carrying out simulation calculation on the performance of the crystalline silicon solar cell, and analyzing carrier generation rate and short-circuit current density factors; 7, performing statistical analysis on all calculation results in the step 6, and calculating refraction, reflectivity, carrier generation rate and short-circuit current density factors of the solar cell; according to the invention, the problems of unclear cell efficiency influence factors, incomplete optical properties and small dimensions are solved from the microscopic perspective.

The invention belongs to the technical field of solar cells, and particularly relates to a crystalline silicon solar cell with a Poly-Finger structure and a preparation process of the crystalline silicon solar cell. The preparation method comprises the following steps of: 1, sequentially forming a SiO2 tunneling oxide layer and a first N + poly layer with the thickness of 30nm-70nm on the back surface of a silicon wafer; step 2, forming a layer of SiO2 mask in a non-metal region on the back surface of the silicon wafer; 3, forming a second N + poly layer on the back surface of the silicon wafer; step 4, removing PSG in the non-metal region by laser; and 5, carrying out RCA cleaning on the battery piece, removing the poly layer on the front side and the side surface of the battery piece, and the second N + poly layer and the SiO2 mask in the non-metal area on the back side, and drying the battery piece. According to the preparation method provided by the invention, the thickness of the poly in the non-printing area can be accurately controlled, the poly-finger structure on the back surface of the battery is not influenced, and electric leakage of the battery is not caused.

The embodiment of the invention discloses copper paste, a preparation method of the copper paste and an N-type crystalline silicon solar cell. The copper paste comprises an organic additive, micron-scale spherical copper powder, nano-scale spherical copper powder, an organic binder and glass powder, wherein the mass percent of the organic additive in the copper paste is 1.5%-2.2%; the mass percent of the micron-sized spherical copper powder in the copper paste is 70%-77%; the mass percent of the nanoscale spherical copper powder in the copper paste is 3-5%; the mass percent of the organic adhesive in the copper paste is 15.3%-21.3%; and the mass percent of the glass powder in the copper paste is 2.2-2.5%. The copper paste is low in cost and high in quality, the copper paste is applied to the preparation process of the back grid line electrode of the N-type crystalline silicon solar cell, and the problem that the production cost is increased due to the fact that existing silver paste is expensive is solved.

The invention provides conductive paste, a conductive electrode, a preparation method and a crystalline silicon solar cell. The conductive paste comprises the following components by weight: 3-7wt% of glass powder; 9-15 wt% of an organic carrier; 78 to 88 wt% of silver powder; the glass powder comprises the following components according to the amount of substance: 24-36 mol% of PbO; teO2: 40 to 60 mol%; siO2: 0 to 10 mol%; bi2O3: 0 to 10 mol%; 0-16 mol% of an alkali metal oxide; wherein the molar ratio of the PbO to the TeO2 is 0.4 to 0.8; and the grain size of the silver powder is 20-150nm. By controlling the adding proportion of PbO and TeO2 in the glass powder, the solubility of the glass powder to silver ions is enhanced, and meanwhile, the high-temperature fluidity and corrosivity of the glass powder are balanced; and by controlling the grain size of the silver powder, the silver powder and the glass powder have matched sinterability.

The invention belongs to the field of crystalline silicon solar cells, and relates to a slice cell and a preparation method and equipment thereof, and the preparation method comprises the steps: providing a solar cell; cutting the solar cell to obtain a slice cell which has a front surface, a back surface and a cutting surface; passivating the cutting surface to form a passivation layer; the slice batteries are stacked into a slice battery stack in the mode that the passivation layers face the same direction, the end, close to the passivation layers, of the first main surface of the slice battery stack is provided with a first area, and the end, close to the passivation layers, of the second main surface of the slice battery stack is provided with a second area; carrying out first laser annealing treatment on the first area; overturning the sliced battery stack; and carrying out second laser annealing treatment on the second area. The first region and the second region are subjected to two-time separated laser annealing treatment, so that hydroxyl groups and defects generated when an oxide film layer is plated are eliminated, the annealing uniformity is improved, the yield of a photovoltaic module is improved, and the overall structure of a solar cell is not damaged.

The invention relates to the technical field of solar cells, in particular to a crystalline silicon solar cell with a tunneling oxide layer structure and a preparation method thereof, and the crystalline silicon solar cell comprises a suede structure, a boron diffusion layer, an aluminum oxide layer and an anti-reflection film which are sequentially stacked on the front side; the tunneling oxide layer, the phosphorus-doped polycrystalline silicon layer and the anti-reflection film are sequentially stacked on the back surface; a complete tunneling oxide layer and a complete phosphorus-doped polycrystalline silicon layer are reserved in a back metallization region, and a non-metallization region is etched to form a tower footing structure; according to the invention, by optimizing the structural design of the back tunneling oxide layer and the phosphorus-doped polycrystalline silicon layer and combining laser and wet processing processes, the contradiction between the thickness of the polycrystalline silicon layer and parasitic absorption and the balance problem between the area of a graphical region and a fill factor in the prior art are effectively solved, so that the conversion efficiency of the cell is remarkably improved.

The invention relates to the technical field of solar cells, and particularly discloses a method for improving UV attenuation of an N-type crystalline silicon solar cell and the N-type crystalline silicon solar cell. The method comprises the following steps: depositing an aluminum oxide film layer on the surface of N-type crystalline silicon; then, bombardment gas is adopted for conducting gas ionization bombardment treatment on the surface of the aluminum oxide film layer, and the bombardment gas is one or more combinations of laughing gas and rare gas and at least comprises laughing gas; and finally depositing a silicon nitride film layer. The laughing gas ionization bombardment can form a more compact aluminum nitride or aluminum oxynitride hydrogen blocking layer and release hydrogen, and the rare gas ionization bombardment can increase the negative charge density of the aluminum oxide film layer. Silicon nitride deposition, silk-screen printing, sintering and light injection processes do not need to be adjusted, no negative influence is caused on the short-circuit current and contact resistivity of the cell, the field passivation effect can be improved while the hydrogen passivation proportion is reduced, UV attenuation is effectively improved, and the full-life-cycle power generation amount of the cell is improved.

The invention relates to the field of photovoltaic technology, and provides a laminated cell and a preparation method thereof, and a photovoltaic module, the laminated cell comprises a bottom cell and a top cell which are laminated, the bottom cell comprises a crystalline silicon solar cell, and the top cell comprises a perovskite solar cell; the perovskite solar cell comprises a perovskite light absorption layer and a functional layer which are arranged in a stacked mode, the functional layer comprises a first functional layer and a second functional layer which are arranged in a stacked mode, the first functional layer is adjacent to the perovskite light absorption layer, and the second functional layer is arranged on the side, away from the perovskite light absorption layer, of the first functional layer; the first functional layer comprises a titanium oxide nanorod array, and the second functional layer comprises a zirconium oxide layer with a plurality of pores. The laminated cell provided by the invention has the advantages that the optical utilization rate is improved, so that the photoelectric conversion efficiency is improved.

The invention discloses a polymer-perovskite quantum dot composite adhesive film and a preparation method and application thereof, belonging to the technical field of photovoltaic adhesive films, preparing perovskite quantum dots based on a solution method, using a surface modifier, and under the action of water and oxygen, the modifier adsorbed on the surface of the perovskite quantum dots is slowly hydrolyzed or oxidized to form an inorganic thin layer. The perovskite quantum dot solution is then mixed with a polymer solution, and the solvent is removed to obtain a composite masterbatch. The masterbatch is mixed with polymer particles and melt-extruded to obtain a polymer-perovskite quantum dot composite adhesive film. The modified adhesive film has significantly enhanced thermal stability. The adhesive film is used to encapsulate crystalline silicon solar cells, which can significantly improve the photoelectric conversion efficiency of the device.

This application provides a passivation structure and its preparation method, as well as a silicon solar cell and its preparation method. The passivation structure includes a first aluminum oxide layer, a first aluminum nitride layer, a second aluminum oxide layer, and a second aluminum nitride layer stacked together. The first aluminum oxide layer directly contacts the silicon edge and repairs cutting damage and dangling bonds through chemical passivation. It adapts to the p-type silicon region with a negative fixed charge. The first aluminum nitride layer passivates the n-type silicon with a positive fixed charge. The high hydrogen content enhances defect repair, and the dense structure blocks impurities from intruding. The second aluminum oxide layer supplements the negative charge to improve the passivation effect of the p-type silicon and forms stress complementarity with the aluminum nitride layer to prevent film cracking. The second aluminum nitride layer resists stringing and lamination damage, blocks moisture and corrosion, and ensures long-term performance. This structure achieves optimal simultaneous passivation of p / n-type silicon through charge complementarity and synergistic hydrogen passivation, improving the minority carrier lifetime at the cell edge, the implicit open-circuit voltage, and the module power, and solving the pain points of incomplete passivation and poor stability.

The present application relates to a silicon solar cell. In one example, a silicon solar cell includes a silicon substrate including an antimony element; and a carrier separation layer, formed on the silicon substrate. At least some regions of the carrier separation layer on a side close to the silicon substrate have an antimony-containing layer. The antimony-containing layer includes the antimony element. A peak concentration of the antimony element in the antimony-containing layer is a1, and a1 is equal to or greater than 1E13 atoms / cm3.

The invention discloses a benzotriazole light conversion material, a preparation method and application of the benzotriazole light conversion material in preparation of a solar cell packaging film. When a light conversion packaging film formed based on the benzotriazole light conversion material is attached to an organic solar cell, a dye-sensitized solar cell, a crystalline silicon solar cell, a perovskite solar cell and a laminated cell composed of the perovskite cell and the crystalline silicon cell, the ultraviolet stability of the solar cell can be improved; and the power conversion efficiency of the solar cell can be maintained.

The invention provides an ultralight crystalline silicon solar photovoltaic cell, and relates to the technical field of photovoltaic cells, the ultralight crystalline silicon solar photovoltaic cell comprises a first silica gel packaging material, a crystalline silicon cell piece, a welding strip and a second silica gel packaging material, the crystalline silicon cell piece is arranged above the first silica gel packaging material, the welding strip is arranged above the crystalline silicon cell piece, and the second silica gel packaging material is arranged above the second silica gel packaging material. The second silica gel packaging material is arranged above the welding strip; the first silica gel packaging material and the second silica gel packaging material are used for packaging the crystalline silicon cell piece, a conventional scheme of adding a glue film to glass or other light front back plates is replaced, the ultra-light crystalline silicon solar cell which is low in cost, high in efficiency, ultra-light, flexible and wide in temperature range adaptability is achieved, and the ultra-light crystalline silicon solar cell is suitable for being applied to the fields of near space, satellites and the like; the high-efficiency and light-weight characteristics of the crystalline silicon battery are considered, the power mass ratio is higher, the cost is low, silica gel is used for packaging the battery, the wide-temperature-range adaptability is guaranteed, and the battery passes a TC400 cold and hot cycle test.

The present invention provides a palladium-free nickel plating process for crystalline silicon solar cells and a crystalline silicon solar cell, and specifically relates to the technical field of solar cell preparation. The palladium-free nickel plating process comprises the following steps: A. printing an activation liquid on the surface of a silicon substrate, drying it, and then activating it to obtain a silicon substrate containing an activation layer; B. chemically nickel-plating the silicon substrate containing the activation layer to obtain a nickel layer. The palladium-free nickel plating process for crystalline silicon solar cells provided by the present invention has low process cost and is pollution-free. The formed activation layer not only improves the bonding force between the nickel layer and the silicon substrate, but also makes the nickel layer on the activation layer uniform in thickness and good in density, thereby establishing a good seed layer for the subsequent copper plating layer, thereby ensuring the quality of the solar cell and improving the electrical performance of the crystalline silicon solar cell.

The present invention discloses a multi-output crystalline silicon solar cell structure, comprising a plurality of structural units arranged side by side on a substrate. Each structural unit comprises a multi-layer power generation structure composed of a plurality of independent low-power power generation units stacked together. Adjacent low-power power generation units are insulated from each other by an insulating layer. The width of the multiple low-power power generation units and the insulating layer gradually decreases from bottom to top, so that the cross-section of each structural unit is an isosceles trapezoid with a narrow top and a wide bottom. Each low-power power generation unit is provided with a set of output ports. A focusing baffle is provided between adjacent structural units. The focusing baffle is composed of a plano-convex lens area, a buffer area, and a support area, from top to bottom. The focusing baffle is embedded between adjacent structural units through the support area, and is used to focus incident light between the two adjacent structural units for multiple reflection. The battery is easy to use and can provide electricity for small and micro-power applications without cutting the battery chip.

The utility model discloses a back contact solar cell, a cell string, an assembly and a photovoltaic system, and relates to the field of silicon solar cells. The back contact solar cell comprises a silicon substrate, a first doping layer, a second doping layer, a positive electrode grid line, a negative electrode grid line, a first test point and a second test point. The second doping layer is in composite contact with the first doping layer at a preset position to form an electric leakage composite contact structure; the first test point comprises a first test PAD point and a second test PAD point, the first test PAD point is electrically connected with the positive grid line, and the second test PAD point is electrically connected with the negative grid line. The second test point comprises a third test PAD point and a fourth test PAD point, the third test PAD point is electrically connected with the positive grid line, and the fourth test PAD point is electrically connected with the negative grid line. By implementing the embodiment, the characterization of the hot spot resistance effect can be realized at the battery end.