A back contact heterojunction solar cell and a manufacturing method thereof using a laser ablation process

Abstract

The application relates to a back contact heterojunction solar cell manufacturing method adopting a laser ablation process, which comprises the following steps: forming a first conductive type film layer and an insulating film layer on a second main surface of a semiconductor substrate in sequence; forming a silicon-based enhanced adhesion film layer and a laser absorption sacrificial film layer on the insulating film layer in sequence; removing the laser absorption sacrificial film layer and the silicon-based enhanced adhesion film layer below the laser absorption sacrificial film layer in a partial region by adopting a laser ablation process; removing the exposed insulating film layer and the first conductive type film layer below the insulating film layer in sequence by adopting a chemical etching process; then performing chemical cleaning; and finally depositing a second conductive type film layer. The application aims to ensure the adhesion between the film layers by taking the silicon-based enhanced adhesion film layer as an intermediate between the insulating film layer and other film layers; meanwhile, the laser ablation process is combined with the laser absorption sacrificial film layer to prevent the first conductive type film layer from being subjected to thermal decay due to high temperature in the subsequent process, so that the power generation decay speed is effectively reduced.

Description

Technical Field

[0001] This invention relates to a back-contact heterojunction solar cell and its manufacturing method using laser ablation technology. Background Technology

[0002] Compared to photovoltaic manufacturing technologies characterized by high-temperature diffusion, heterojunction technology features low surface recombination rates and high open-circuit voltages, but it is more sensitive to surface contact damage. There is a significant gap between the average mass production performance and the reported highest electrical properties of heterojunction solar cells. The electrical fluctuations in heterojunctions often manifest as fluctuations in the fill factor, which are related to surface mechanical damage and subsequent chemical corrosion. Summary of the Invention

[0003] One of the objectives of this invention is to provide a back-contact heterojunction solar cell with good bonding between its film layers, which effectively reduces the rate of power generation degradation.

[0004] One objective of this invention is to provide a method for manufacturing a back-contact heterojunction solar cell using a laser ablation process. By using a silicon-based reinforced adhesion film layer as an intermediary between the insulating film layer and other film layers, the adhesion between the film layers is ensured. At the same time, the laser ablation process is combined with a laser absorption sacrificial film layer to prevent the first conductive film layer from experiencing thermal degradation due to high temperatures in subsequent processes, thereby effectively reducing the rate of power generation degradation.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A back-contact heterojunction solar cell includes a semiconductor substrate, a first conductive film layer disposed on a portion of a second main surface of the semiconductor substrate, and a second conductive film layer disposed on other portions of the second main surface of the semiconductor substrate and on a portion of the first conductive film layer. The area of ​​the first conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a first conductive region, and the area of ​​the second conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a second conductive region. An insulating film layer and a silicon-based reinforcing adhesion film layer are disposed between the first conductive film layer and the second conductive film layer located in the first conductive region. The insulating film layer is disposed on the first conductive film layer, and the silicon-based reinforcing adhesion film layer is disposed on the insulating film layer.

[0007] A method for manufacturing a back-contact heterojunction solar cell using laser ablation technology involves sequentially forming a first conductive film layer and an insulating film layer on the second main surface of a semiconductor substrate, followed by sequentially forming a silicon-based reinforcement adhesion film layer and a laser absorption sacrificial film layer on the insulating film layer; removing a portion of the laser absorption sacrificial film layer and the underlying silicon-based reinforcement adhesion film layer using laser ablation technology; sequentially removing the exposed insulating film layer and the underlying first conductive film layer using chemical etching technology; then performing chemical cleaning; and finally depositing a second conductive film layer.

[0008] Compared with the prior art, the advantages of the present invention are as follows:

[0009] (1) By using a silicon-based reinforced adhesion film layer, which acts as an intermediary between the insulating film layer and other film layers, the adhesion between the film layers is guaranteed, the film layers are firmly bonded together, and there is no delamination problem.

[0010] (2) The laser ablation process is combined with the laser absorption sacrificial film to prevent the first conductive film from thermally decaying due to high temperature in subsequent processes, thereby effectively reducing the rate of power generation decay.

[0011] (3) By utilizing the interference phenomenon, the optical absorption of the target processing film is 5 times that of the optical absorption of the semiconductor substrate or the film to be protected. When opening is made by laser ablation, the impact on the semiconductor substrate is almost negligible.

[0012] (4) The optical properties and film thickness of the protective layer covering the laser absorption layer determine that it does not affect the laser absorption layer and the optical interference enhancement effect. The protective layer outside the laser ablation area can ensure that the silicon-based reinforcement film layer covered by it is not destroyed by the chemical corrosion process. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view of a silicon wafer after a first conductive film layer is formed on the back side of the wafer, and an insulating film layer, a silicon-based reinforcement film layer, and a laser absorption sacrificial film layer are formed on the first conductive film layer.

[0014] Figure 2 This is a schematic cross-sectional view formed after removing the laser-absorbing sacrificial film layer and the silicon-based reinforcing film layer by laser ablation, and then removing the exposed insulating film layer 14 and the first conductive film layer below it by chemical etching to expose the opening area of ​​the second conductive region in one embodiment of the present invention.

[0015] Figure 3 This is a schematic cross-sectional view of a silicon wafer formed by chemical cleaning to clean the silicon wafer and remove the surface film layer of the laser absorption sacrificial film layer, forming a third intrinsic amorphous silicon layer, an amorphous film layer or an oxygen-containing microcrystalline film layer and a silicon nitride antireflection film layer on the front side of the silicon wafer using a PECVD device, and forming a second semiconductor film layer on the back side of the silicon wafer.

[0016] Figure 4 This is a schematic cross-sectional view formed after a portion of the second conductive film layer in the first conductive region is ablated using a laser ablation process, and the exposed insulating film layer is removed by a chemical etching process to expose the first conductive film layer and complete the opening of the first conductive region.

[0017] Figure 5 This is a schematic cross-sectional view of a silicon wafer after a transparent conductive film and a seed metal layer are formed on the back side of the wafer using a PVD device, according to one embodiment of the present invention.

[0018] Figure 6 This is a schematic cross-sectional view of a silicon wafer after a perforated insulating groove pattern mask is formed on the back side using a printing process, according to one embodiment of the present invention.

[0019] Figure 7 This is a schematic cross-sectional view of a structure formed after the exposed transparent conductive film and the seed metal layer beneath it are removed by a chemical etching process in one embodiment of the present invention.

[0020] Figure 8 This is a schematic cross-sectional view formed after removing the insulating groove pattern mask with an alkaline cleaning solution and making a conductive paste in the metal grid area using a printing or spraying process, according to one embodiment of the present invention.

[0021] Figure 9 Is Figure 1 The image shows the intensity distribution of a 532nm wavelength laser incident on the back of a silicon wafer, across various film layers.

[0022] Figure 10 Is Figure 4 The image shows the intensity distribution of a 532nm wavelength laser incident on the back of the solar cell, along with the intensity distribution of the laser light in the first conductive film layer and the second semiconductor layer.

[0023] Figure 11 The image shows the presence of a silicon-based reinforced adhesion film in a TEM-EDAX cross-sectional view; the left image is a HAADF image generated by EDAX mapping, with the transition layer being a relatively non-conductive structure; the middle and right images show the spatial distribution of N and Si elements in the film structure, respectively. Detailed Implementation

[0024] A back-contact heterojunction solar cell includes a semiconductor substrate, a first conductive film layer disposed on a portion of a second main surface of the semiconductor substrate, and a second conductive film layer disposed on other portions of the second main surface of the semiconductor substrate and on a portion of the first conductive film layer. The area of ​​the first conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a first conductive region, and the area of ​​the second conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a second conductive region. An insulating film layer and a silicon-based reinforcing adhesion film layer are disposed between the first conductive film layer and the second conductive film layer located in the first conductive region. The insulating film layer is disposed on the first conductive film layer, and the silicon-based reinforcing adhesion film layer is disposed on the insulating film layer.

[0025] The silicon-based reinforced adhesion film is a crystalline silicon layer.

[0026] The second conductive film layer covering the first conductive area has multiple grooves or multiple countersunk holes that expose the first conductive area.

[0027] The back-contact heterojunction solar cell further includes a first conductive layer disposed on a first conductive region and electrically connected to a first conductive film layer, a first electrode disposed on the first conductive layer, a second conductive layer disposed on a second conductive region and electrically connected to a second conductive film layer, and a second electrode disposed on the second conductive layer; an insulating separation groove is provided between the first conductive layer and the second conductive layer.

[0028] A laser absorption layer is disposed between the silicon-based reinforced adhesion film and the second conductive film.

[0029] A method for manufacturing a back-contact heterojunction solar cell using laser ablation technology involves sequentially forming a first conductive film layer and an insulating film layer on the second main surface of a semiconductor substrate, followed by sequentially forming a silicon-based reinforcement adhesion film layer and a laser absorption sacrificial film layer on the insulating film layer; removing a portion of the laser absorption sacrificial film layer and the underlying silicon-based reinforcement adhesion film layer using laser ablation technology; sequentially removing the exposed insulating film layer and the underlying first conductive film layer using chemical etching technology; then performing chemical cleaning; and finally depositing a second conductive film layer.

[0030] The method for manufacturing the back-contact heterojunction solar cell specifically includes the following steps:

[0031] Step A. It includes step A, forming a first conductive film layer with a surface-covered insulating film layer, a silicon-based reinforcing adhesion film layer and a laser absorption sacrificial film layer on a portion of the second main surface of the semiconductor substrate, to form a first conductive region of the first conductive type;

[0032] Step B: After chemically cleaning the semiconductor substrate treated in Step A, a second conductive film layer is formed on its second main surface. The area where the second conductive film layer is in direct contact with the second main surface of the semiconductor substrate forms a second conductive region of the second conductive type.

[0033] Step C: Remove a portion of the second conductive film layer covering the area inside the first conductive region using laser discontinuous etching or laser linear etching.

[0034] Step D: Remove the insulating film layer that does not cover the second conductive film layer by chemical etching;

[0035] Step E: A conductive layer is formed on the second main surface of the semiconductor substrate after the process in step D.

[0036] Step F involves setting a first electrode on the conductive layer located in the first conductive region, setting a second electrode on the conductive layer located in the second conductive region, and slotting to form a separation insulation between the first conductive region and the second conductive region.

[0037] The specific method for step A is as follows:

[0038] a1. A first conductive film layer and an insulating film layer are sequentially formed on the second main surface of a semiconductor substrate;

[0039] a2. A silicon-based reinforced adhesion film and a laser absorption sacrificial film are sequentially formed on the insulating film layer;

[0040] a3. The laser absorption sacrificial film layer and the underlying silicon-based reinforced adhesion film layer in the area outside the first conductive region are removed by laser ablation process;

[0041] a4. The exposed insulating film layer and the first conductive film layer beneath it are removed sequentially using a chemical etching process.

[0042] The silicon-based reinforced adhesion film is fabricated by depositing a silicon thin film on an insulating film layer using plasma-enhanced chemical vapor deposition (PECVD) with high power density. Specifically, the process gases are mainly silane and hydrogen, and the deposition power density is 1000-3000 W / m². 2 The process gas pressure is 100-400 Pa, and the deposition thickness is 3-15 nanometers, preferably 5-8 nanometers. Preferably, a planar capacitively coupled PECVD equipment is used, with an RF operating frequency of 13.56 MHz; or a furnace tube PECVD equipment is used, with an RF operating frequency of 20-80 kHz. Due to the influence of the ambient atmosphere, a small amount of nitrogen and oxygen may be present in the silicon-based reinforced adhesion film, but the atomic density should be less than 1%. The silicon-based reinforced adhesion film is a connecting layer between the insulating film and other films. It has a high deposition power density, and the deposition conditions are close to those of a silicon nitride layer (i.e., a type of insulating film). Some grains interpenetrate with the insulating film, resulting in good adhesion. However, its film properties are a mixture of amorphous silicon and microcrystalline silicon, and the stress of the film is less than that of silicon nitride and similar to that of amorphous silicon. Therefore, it also has good adhesion to the films covering the silicon-based reinforced adhesion film, acting as a transition stress connector between the insulating film and other films, thus enhancing adhesion.

[0043] The fabrication of the laser absorption sacrificial film includes forming a laser absorption layer on a silicon-based reinforced adhesion film and forming a protective layer on the laser absorption layer; the protective layer is an anti-corrosion mask that protects the amorphous silicon layer and the underlying film layer when the exposed insulating film is corroded.

[0044] The laser absorption layer is fabricated using plasma-enhanced chemical vapor deposition (PECVD) to deposit an amorphous silicon layer. The fabrication process is identical to that of common heterojunction hydrogenated amorphous films, with a fabrication temperature below 230 degrees Celsius to ensure sufficient direct optical bandgap absorption for 532 nm laser wavelengths and prevent crystallization. Specifically, the deposition power density is 80-400 W / m². 2 The process gases are silane and hydrogen, the process gas pressure is 40-150 Pa, and the deposition thickness is 10-20 nanometers. Preferably, a planar capacitively coupled PECVD equipment is used, with an RF operating frequency of 13.56 MHz or 40 MHz.

[0045] The protective layer is fabricated by depositing a protective layer on the laser absorption layer using plasma-enhanced chemical vapor deposition. Specifically, a silicon nitride film (8-20 nm thick) and an amorphous silicon film (3-7 nm thick) are sequentially prepared using a PECVD device.

[0046] Chemical cleaning before depositing the second conductive film layer cleans the semiconductor substrate and removes the protective layer.

[0047] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0048] like Figures 1 to 11 The diagram shown is an embodiment of a back-contact heterojunction solar cell and its manufacturing method using laser ablation technology provided by the present invention.

[0049] Czochralski-grown or cast-crystal ingots are cut with diamond wire or slurry to form silicon wafers with a thickness of 130-250 micrometers. Although cast-crystal ingots have a higher proportion of monocrystalline silicon, the cells still contain a significant proportion of polycrystalline grain boundaries and lattice defects. If cast-crystal silicon wafers are used, they need to undergo pretreatment at different temperature ranges before being introduced into the heterojunction production process to achieve gettering and dangling bond saturation. After pretreatment, the silicon wafers first undergo tank solution pre-cleaning to remove surface organic contaminants and large particles. Then, they are de-damaged and texturized with alkaline solution to form a roughened light-trapping structure, followed by RCA cleaning (or an equivalent RCA cleaning solution formulation), and finally, HF solution to remove the surface oxide layer, deionized water cleaning, and surface drying. In the process flow, a front-textured and back-polished structure can be formed by first texturing and roughening both sides and then alkaline polishing on one side, or by depositing an alkaline-resistant etching film on one side of the double-polished silicon wafer and then texturing.

[0050] After solution cleaning, a first conductive film layer is prepared using a PECVD device, namely a surface passivation film layer (undoped) (such as the first intrinsic amorphous silicon layer 11) and a doped film layer (such as the N-type semiconductor film layer 12). The PECVD device power supply is 13.56MHz, 26MHz, or 40MHz, preferably 13.56MHz. The process gas for the first intrinsic amorphous silicon layer 11 contains all or a combination of silane (SiH4), hydrogen (H2), carbon dioxide (CO2), and methane (CH4). The process gas for preparing the N-type semiconductor film layer 12 contains all or a combination of silane (SiH4), hydrogen (H2), carbon dioxide (CO2), and phosphine (PH3).

[0051] Traditional heterojunction N-type and P-type amorphous silicon have very weak lateral conductivity, and heterojunction cells usually require full-area contact to form the collecting electrode. However, the back-contact solar cell of this invention uses a small-scale local opening for laser processing to control laser processing damage. To achieve the above objectives, the N-type semiconductor film layer 12 adopts a highly doped amorphous process or a microcrystalline process. To improve the selectivity of laser ablation (the lower layer of the film to be ablated needs to effectively absorb the laser to protect the functional layer), the N-type semiconductor film layer 12 can use an oxygen-containing microcrystalline film layer, which includes a three-stage process: (1) first, an oxygen-free incubation layer with a high H2 / SiH4 ratio, the purpose of which is to promote the formation of microcrystalline state; (2) an oxygen-containing microcrystalline layer, oxygen-containing microcrystalline μc-SiO x The film-forming rate of H(N) is controlled at 0.2-2 Å / s, preferably 0.6-0.8 Å / s; oxygen-containing microcrystalline μc-SiO x The thickness of H(N) on the film-forming surface is 40-200 angstroms, preferably 60-120 angstroms; (3) Non-oxygen-containing contact layer, the purpose of which is to reduce the contact resistance between the TCO film layer and resist the corrosive effect of hydrofluoric acid on the film layer.

[0052] An insulating film layer deposited by PECVD is placed between the first conductive film layer (11, 12) and the second conductive film layer (26, 27) to prevent leakage current in the device. The insulating film layer 14 is any or a combination of silicon nitride, silicon dioxide, silicon oxide, and silicon oxynitride. For the convenience of laser processing, an amorphous silicon film layer 16 is placed on top of the insulating film layer 14 as a laser absorption sacrificial film layer, and a protective layer 17 as a mask for subsequent etching of the insulating film layer 14. A transition layer 15 (i.e., a silicon-based reinforcement adhesion film layer) is required between the insulating film layer 14 and the amorphous silicon film layer 16. A high-power-density PECVD process is used to deposit the silicon thin film, with a process gas pressure higher than 150 Pa and a hydrogen to silane gas flow ratio higher than 80.

[0053] A pulsed laser, preferably a green laser with a pulse width of less than 20 nanoseconds, is used for etching. Following this, an acidic solution containing fluoride ions is applied for wet etching to remove portions of the composite film 13. Preferably, the laser uses green light with a wavelength of 532 nanometers, and the laser energy density is selected between 100-150% (when the laser energy density is 100%, the laser absorption layer is just completely ablated). The wet etching uses a 1-5% hydrofluoric acid solution, and the insulating film is removed at room temperature or below 40 degrees Celsius, with the etching rate controlled at 0.5-4 Å / s. Preferably, a mixed solution of ammonium fluoride (NH4F) and hydrofluoric acid (or BOE solution) is used to enhance the stability of the etching rate.

[0054] The table below shows the absorption of the first conductive film layer (11 and 12), the transition layer 15, and the amorphous silicon film layer 16, provided that the transparent dielectric film is 50-100 nm silicon nitride (i.e., insulating film layer 14).

[0055]

[0056] like Figure 2 As shown, an opening region of the P-type conductive area is formed on the back of the battery (i.e., the region where the second conductive film layer and the silicon wafer 00 are in direct contact).

[0057] After chemical cleaning, a second conductive film (a second intrinsic amorphous silicon layer 26 and a P-type semiconductor film 27) is deposited on the back side of the silicon wafer using PECVD. The PECVD equipment power supply uses 13.56MHz, 26MHz, or 40MHz, preferably 13.56MHz. The process gas for the second intrinsic amorphous silicon layer 26 contains all or a combination of silane (SiH4), hydrogen (H2), carbon dioxide (CO2), and methane (CH4). The process gas for preparing the P-type semiconductor film 27 contains all or a combination of silane (SiH4), hydrogen (H2), carbon dioxide (CO2), and diborane (B2H6) or TMB. Figure 3 As shown, the front-side coating sequence of silicon wafer 00 is: a third intrinsic amorphous silicon layer 21, an amorphous film layer or an oxygen-containing microcrystalline film layer 22, and a silicon nitride antireflective film layer 23. The amorphous film layer or oxygen-containing microcrystalline film layer 22 is N-type doped to prevent outdoor PID or UV degradation of the battery. The process gas for the front-side (light-receiving surface) third intrinsic amorphous silicon layer 26 contains all or a combination of silane (SiH4), hydrogen (H2), carbon dioxide (CO2), and methane (CH4).

[0058] like Figure 4As shown, a portion of the second conductive film layer in the first conductive region is removed using laser ablation, and then the exposed insulating film layer 13 is removed using chemical etching with hydrofluoric acid, forming the N-type electrode opening region 28. Preferably, to avoid laser damage (including thermal damage caused by temperature rise and excessively high local energy caused by interference), the back side of the silicon wafer 00 is chemically polished to eliminate the pyramid-shaped light-trapping structure. The laser used for opening is a spatially shaped flat-top laser to ensure that the energy in the processing area tends to be uniform. The laser used for opening is a pulsed laser, preferably a green laser, violet laser, or ultraviolet laser with a pulse width of less than 100 picoseconds. To avoid a decrease in power generation efficiency due to laser damage, a discontinuous point laser is used for etching, and the N-type electrode opening region 28 is a series of unconnected laser-processed holes. The table below shows the optical absorption of the first semiconductor layer (11+12, the first conductive film layer) and the second semiconductor layer (26+27, the second conductive film layer) with the transparent dielectric film being 50-100nm silicon nitride (i.e., insulating film layer 14).

[0059]

[0060] like Figure 5 As shown, after the laser aperture opening process, a conductive layer [i.e., a transparent conductive film (TCO) 30 and a seed metal layer 40] is prepared by PVD magnetron sputtering. The TCO material can be an indium oxide thin film doped with tin oxide, titanium oxide, zinc oxide, or gallium oxide, wherein indium oxide (In2O3) is the main material, accounting for more than 90% by weight. Preferably, the doping material contains at least one of tin oxide, titanium oxide, zinc oxide, or gallium oxide, accounting for 0-10% by weight. The target material used for PVD can also be pure indium oxide, and then H2 or water vapor is introduced into the process gas to form a doped In2O3:H thin film. The seed metal layer contains at least a copper layer.

[0061] Since TCO and the seed metal layer are full-area coating methods, such as Figure 6 As shown, physical insulation of the first and second conductive regions is required after the PVD process. Preferably, one or more layers of protective ink 45 are printed using screen printing. Figure 7 As shown, chemical etching is used to remove the exposed TCO and seed metal layer, followed by ink removal. To form effective electrical contact with the solder ribbon, interconnected metal grid lines and a certain number of pads need to be prepared. These metal grid lines and pads can be fabricated using inkjet printing of metal paste (such as silver paste) or screen printing. Figure 8 As shown. To protect the seed metal layer from oxidation or to enhance the conductivity of the fine grid, silver paste, carbon paste, or aluminum paste can also be printed above the metal fine grid lines.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a back-contact heterojunction solar cell using laser ablation technology, characterized in that: After forming a first conductive film layer and an insulating film layer sequentially on the second main surface of the semiconductor substrate, a silicon-based reinforcement adhesion film layer and a laser absorption sacrificial film layer are sequentially formed on the insulating film layer; a laser ablation process is used to remove a portion of the laser absorption sacrificial film layer and the silicon-based reinforcement adhesion film layer below it, and a chemical etching process is used to sequentially remove the exposed insulating film layer and the first conductive film layer below it. After chemical cleaning, a second conductive film layer is deposited on the second main surface of the semiconductor substrate; the thickness of the insulating film layer is 50-70 nanometers, and the insulating film layer is a silicon nitride layer. The silicon-based reinforced adhesion film is fabricated by depositing a silicon thin film on an insulating film using plasma-enhanced chemical vapor deposition at high power density. The process gases are silane and hydrogen, the deposition power density is 1000-3000 W / m², the process gas pressure is 100-400 Pa, and the deposition thickness is 3-15 nanometers. The silicon-based reinforced adhesion film is a mixture of amorphous silicon and microcrystalline silicon, and the stress of this film is less than that of silicon nitride. The fabrication of the laser absorption sacrificial film includes forming a laser absorption layer on a silicon-based reinforced adhesion film and forming a protective layer on the laser absorption layer. The protective layer is a corrosion-resistant mask that protects the amorphous silicon layer and the underlying film layer when the exposed insulating film is etched. The laser absorption layer is fabricated by depositing an amorphous silicon layer using plasma-enhanced chemical vapor deposition (PECVD), controlling the fabrication temperature to be less than 230 degrees Celsius, the deposition power density to be 80-400 W / m², the process gases to be silane and hydrogen, the process gas pressure to be 40-150 Pa, and the deposition thickness to be 10-20 nanometers. The protective layer is fabricated by sequentially preparing a silicon nitride film layer with a thickness of 8-20 nanometers and an amorphous silicon film layer with a thickness of 3-7 nanometers using PECVD equipment. The resulting back-contact heterojunction solar cell using laser ablation technology includes a semiconductor substrate, a first conductive film layer disposed on a portion of a second main surface of the semiconductor substrate, and a second conductive film layer disposed on other portions of the second main surface of the semiconductor substrate and on a portion of the first conductive film layer. The area of ​​the first conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a first conductive region, and the area of ​​the second conductive film layer in direct contact with the second main surface of the semiconductor substrate constitutes a second conductive region. An insulating film layer and a silicon-based reinforcing adhesion film layer are disposed between the first conductive film layer and the second conductive film layer located in the first conductive region. The insulating film layer is disposed on the first conductive film layer, the silicon-based reinforcing adhesion film layer is disposed on the insulating film layer, and a laser absorption layer is disposed between the silicon-based reinforcing adhesion film layer and the second conductive film layer.

2. The method for manufacturing a back-contact heterojunction solar cell using laser ablation technology according to claim 1, characterized in that: It specifically includes the following steps: Step A. It includes step A, forming a first conductive film layer with a surface-covered insulating film layer, a silicon-based reinforcing adhesion film layer and a laser absorption sacrificial film layer on a portion of the second main surface of the semiconductor substrate, to form a first conductive region of the first conductive type; Step B: After chemically cleaning the semiconductor substrate treated in Step A, a second conductive film layer is formed on its second main surface. The area where the second conductive film layer is in direct contact with the second main surface of the semiconductor substrate forms a second conductive region of the second conductive type. Step C: Remove a portion of the second conductive film layer covering the area inside the first conductive region using laser discontinuous etching or laser linear etching. Step D: Remove the insulating film layer that does not cover the second conductive film layer by chemical etching; Step E: A conductive layer is formed on the second main surface of the semiconductor substrate after the process in step D. Step F involves setting a first electrode on the conductive layer located in the first conductive region, setting a second electrode on the conductive layer located in the second conductive region, and slotting to form a separation insulation between the first conductive region and the second conductive region.

3. The method for manufacturing a back-contact heterojunction solar cell using laser ablation technology according to claim 1, characterized in that: Multiple grooves or countersunk holes are formed on the second conductive film layer covering the first conductive area to expose the first conductive area.

4. The method for manufacturing a back-contact heterojunction solar cell using laser ablation technology according to claim 1, characterized in that: The back-contact heterojunction solar cell further includes a first conductive layer disposed on a first conductive region and electrically connected to a first conductive film layer, a first electrode disposed on the first conductive layer, a second conductive layer disposed on a second conductive region and electrically connected to a second conductive film layer, and a second electrode disposed on the second conductive layer; an insulating separation groove is provided between the first conductive layer and the second conductive layer.

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