Laser Ablation Processes for Solar Cell Manufacturing

A process for improving solar cell efficiency through selective laser patterning. The process involves applying a bias voltage to the solar cell substrate, followed by laser illumination that creates a patterned light spot on the substrate surface. The laser pattern includes a hollow area with a specific geometry, and the substrate's fine grid structure overlaps this hollow area. The laser scanning pattern effectively targets the metal grid lines while avoiding the main grid, thereby selectively reducing contact resistance and improving photoelectric conversion efficiency.

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A method for recycling and repairing photovoltaic modules by selectively removing interfacial defects through laser ablation and/or laser melting. The method targets specific layers in the solar cell structure, using precise wavelength selection to selectively target defects without compromising the module's electrical performance. This selective removal enables the recovery of photovoltaic components, including silicon wafers and glass, for reuse in new solar modules or other applications.

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A laser cutting and passivation method for silicon heterojunction solar cells that enables simultaneous laser cutting and chemical passivation. The method employs a laser system with adjustable power and spot size to precisely cut the solar cell surface while simultaneously applying a passivation solution through controlled spray. The laser cutting process naturally creates micro-fractures that can be effectively passivated through the solution treatment, eliminating the need for separate passivation steps. This approach enables high-accuracy laser cutting while maintaining precise control over the cutting process, making it particularly suitable for mass production of solar cells.

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Reducing edge damage and efficiency loss in cutting solar cells, particularly high-efficiency cells like HJT, by using a two-step laser ablation process instead of mechanical breaking. The method involves first laser ablating a narrow slot in the passivation layer, then using a second laser to cut the silicon layer within the slot. This reduces surface damage compared to cutting both layers together. The first laser forms shallow grooves in the passivation layer, and the second laser cuts the silicon within them. The first laser ablation can be done before or after the second laser cutting, depending on the cutting method used (laser scribing vs nondestructive splitting).

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Laser-based metallization of solar cells for back-contact applications. The process involves creating alternating N-type and P-type semiconductor regions on a substrate, followed by forming a non-conductive material paste between regions. The paste is cured to create a region of non-conductive material that acts as a laser stop during laser ablation. The metal foil is then selectively deposited over the non-conductive regions, with laser ablation selectively removing the metal from the regions between the semiconductor regions. This laser-based patterning approach enables efficient metal isolation for back-contact solar cells while maintaining low-cost processing.

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Reducing thermal damage in laser-induced groove formation in solar cells by employing a novel semiconductor layer that selectively absorbs laser energy. The layer, comprising a material with a higher absorption coefficient than the substrate, is integrated into the solar cell's semiconductor layer. This selective absorption enables thermal damage mitigation during laser groove formation, particularly when using laser wavelengths below 600 nm. The layer can be formed on the substrate's rear surface or in the semiconductor layer, and its absorption characteristics can be optimized for specific laser wavelengths.

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A laser marking method for solar cells that improves the traditional solid-line laser marking technique by optimizing beam parameters. The method employs a green laser with 5-8W power, 50-70kHz frequency, and travel speed of 500-700mm/s to achieve uniform character depth and consistent height. The laser beam's characteristics are tailored to prevent mechanical damage to the silicon wafer, enhance passivation film growth during plasma-enhanced chemical vapor deposition (PECVD) coating, and minimize light-induced defects. This approach enables precise laser marking while preserving the structural integrity of the solar cell substrate.

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A laser cutting system for solar cells that minimizes damage to the cell structure while producing high-quality cuts. The system employs a laser cutting module with a fiber laser and galvanometer control, a heating module that simultaneously heats the laser beam and a cooling module that maintains a stable temperature during the heating process. The laser beam is focused onto the solar cell's internal structure, creating a material modification layer that enables precise cutting without damaging the cell's passivation layer or silicon wafer. The heating and cooling process ensures consistent temperature control throughout the cutting process, eliminating thermal stress-induced cracking and fragmentation.

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Manufacturing method for creating a through groove in solar cells through a novel laser-assisted cutting process. The method employs a laser to selectively cut through the solar cell's thickness while maintaining cell integrity. The laser is positioned at the beginning of the cutting path, ensuring that the battery slice remains intact after the laser operation. This approach enables precise control over the groove depth and orientation without disrupting the cell structure. The laser-assisted method allows for controlled groove creation while preserving the cell's original integrity.

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Tracking laser technology in solar cell manufacturing to prevent misidentification of laser grooves. The technology employs marking laser lines with distinct characteristics, such as non-parallel ends or different widths, to distinguish between laser grooves produced by different laser cutting machines. This enables accurate identification of laser grooves during manufacturing and quality control, ensuring consistent laser alignment and preventing potential issues like misaligned solar cells or modules.

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A novel method for metallizing solar cell structures that enables efficient and cost-effective manufacturing of solar cells through a simplified interconnect process. The method employs laser-assisted metallization using metal ribbons to connect solar cells in series or parallel configurations, eliminating the need for complex interconnects and soldering. The laser metallization process enables direct current flow between cells while maintaining structural integrity, while the metal ribbons facilitate efficient current collection and distribution. This approach enables the creation of solar cells with improved efficiency and manufacturing processes compared to traditional back-contact methods.

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A single solar cell cutting device for automated cell processing in solar panels. The device employs a laser cutting system to create a precise cutting line for individual solar cells. The laser cuts through the cell while simultaneously moving it to the desired position using a precision positioning system. The cutting unit is mounted on a moving platform that can be positioned between the cell and a support module, allowing the cell to be precisely positioned while the laser cuts through it. This approach enables high-precision cell processing without the need for manual cutting, reducing production defects and improving yield.

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A solar cell cutting system that optimizes cell processing while minimizing thermal damage and surface contamination. The system employs a precision laser cutting system with integrated temperature management, enabling controlled thermal ablation of cell surfaces while maintaining structural integrity. The cutting process is precisely controlled to achieve optimal cell segmentation while minimizing thermal damage, ensuring efficient module production with reduced thermal stress. The system incorporates advanced cooling technology to rapidly cool the battery sheet after cutting, preventing thermal-related defects.

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A method and device for cutting solar cells using laser technology to minimize thermal damage while maintaining structural integrity. The method employs dual laser beams to precisely cut solar cells, with the laser beams positioned at specific heights to avoid thermal damage. A liquid cooling system is integrated into the cutting process to rapidly cool the cut solar cells after separation, preventing thermal distortion and improving overall performance. The device features adjustable laser beam positioning, a cooling nozzle system, and a frame for securely mounting the solar cells during the cutting process.

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Laser processing techniques for solar photovoltaic cells achieve high-quality passivation and contact formation through selective metal ablation of silicon dioxide (SiO2) surfaces. The laser ablation process enables precise control over metal deposition and patterning at the nanoscale, while maintaining environmental benignity through dry processing. The technique improves passivation of phosphorus-rich emitter regions by selectively removing hydrogen from SiN layers, enhancing minority carrier lifetime and surface recombination velocity. The process enables high-temperature annealing of SiO2 surfaces to form stable passivation layers, enabling efficient contact formation with metal contacts.

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A novel method for forming contact holes in solar cells by utilizing doped silicon nanoparticles as emitter dopants. The process involves creating doped silicon nanoparticles on a substrate, coating them with a passivation film, and then using a laser beam to selectively melt and form the doped silicon at the emitter junction. This approach enables the formation of contact holes through the doped silicon without compromising the emitter structure or introducing additional processing steps.

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Fabricating solar cell metallization structures for efficient and cost-effective solar cell manufacturing. The method involves creating metallization patterns using laser-induced breakdown spectroscopy (LIBS) to form conductive contacts directly on semiconductor substrates, eliminating the need for traditional metal foil deposition. The metallization patterns are created by selectively exposing the metal foil to a laser beam while maintaining the semiconductor substrate structure. This approach enables the formation of precise contact structures with the semiconductor regions, while maintaining the substrate's original surface integrity. The metallization patterns can be used to create solar cell circuits, strings, or other solar cell structures that enhance efficiency and manufacturing complexity.

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Shingled solar cell assembly process that improves manufacturing efficiency and quality by enabling laser-cutting of solar cells while maintaining alignment during assembly. The process involves laser-cutting the solar cells using a laser beam directed onto the first side of the solar cell structure, followed by separation of the cells into individual pieces. The laser beam is precisely positioned to cut through the solar cells while maintaining alignment with the laser beam's path, ensuring accurate separation. The laser-cut solar cells are then assembled into a shingled array with adhesive applied to the second side of each cell.

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A method to improve the efficiency of photovoltaic cells through laser cutting reduction. The method involves a post-processing step that enhances the material's thermal stability and internal defect control through a silicon oxide passivation layer. This layer, created during the wafer processing, not only protects the cell surface from laser damage but also improves the material's thermal conductivity and internal defect tolerance, thereby reducing laser cutting-induced efficiency losses.

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A method for preparing transparent solar cell components that enables high-speed production of light-transmissive solar cells while maintaining power generation characteristics. The method employs a laser cleaning and scribing process to create precise, insulated regions within the solar cell, followed by a second laser treatment to remove the thin film layer while maintaining the scribed regions. This approach enables the creation of transparent solar cell components with both high transmission efficiency and reliable power generation. The laser cleaning step is performed without damaging the power generation areas, while the second laser treatment precisely removes the thin film without causing short circuits. The laser processing speed of 30 cm/s is significantly higher than traditional machining methods, enabling faster production rates while maintaining operational reliability.

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