Laser Doping Techniques for Solar Cell Efficiency Enhancement

A laser doping method for selective emitter doping in solar cells that eliminates the need for high-energy laser exposure. The method employs a composite laser system that combines a high-energy laser with a specialized shaping device. The laser beam is modulated to create a precisely controlled beam profile that selectively excites the desired dopant elements while minimizing thermal damage to the surrounding material. This approach enables precise selective emitter doping at reduced laser energy levels compared to traditional methods, while maintaining the structural integrity of the substrate.

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A method for manufacturing solar cells that improves efficiency by optimizing the selective emitter region. The method creates a selective emitter by selectively doping the substrate with boron in a region with a doping concentration ratio of 1:3 between the heavily doped and lightly doped regions. This creates a region with a doping concentration that is significantly higher than the lightly doped region, while maintaining a doping concentration ratio of 1:3 in the heavily doped region. The method achieves this through a controlled laser doping process that precisely controls the doping concentration in each region, ensuring uniform doping profiles and minimizing recombination effects.

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Laser doping method and solar cell technology that enables precise selective doping of semiconductor surfaces through optimized laser parameters. The method employs laser selective doping with controlled laser parameters such as scanning speed, spot size, and laser power density. By dynamically adjusting these parameters while maintaining constant scanning speed, the laser power density is increased to enhance boron diffusion through the laser-induced diffusion (LID) process. This approach enables consistent doping profiles across the selective area, while maintaining the necessary laser energy density for high-concentration doping. The method is particularly suitable for achieving precise doping profiles in solar cells, particularly in areas requiring high boron concentrations.

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A laser-activated method for heavy doping of polysilicon in photovoltaic cells, enabling controlled doping without compromising passivation. The method involves locally heating the polysilicon on the tunnel oxide layer to form molten silicon, which then rapidly solidifies to form electrically active impurity atoms. This process enables precise doping control, particularly in polysilicon regions with interface defects, while maintaining passivation quality.

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Laser doping method for solar cells that enables high surface doping concentrations while maintaining deep junctions. The method employs ultraviolet (UV) and green light doping techniques to selectively dope the surface of silicon substrates, creating high surface doping concentrations while maintaining a deep junction depth. This approach addresses the conventional limitations of laser doping by leveraging the unique absorption characteristics of UV and green light in silicon, enabling precise control over doping concentrations and junction depths without compromising material properties.

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Solar cell design and manufacturing process to improve cell efficiency by increasing the sheet resistance difference between the emitter regions. The process involves selectively increasing the doping concentration on the metal contact region of the emitter using a non-pushing diffusion process. This creates a lower sheet resistance metal contact region compared to the non-metal contact region. The metal contact region has higher doping due to laser treatment after diffusion. This reduces contact resistance between the metal grid lines and the cell. The non-metal contact region has lower doping after diffusion and laser due to oxidation. This increases sheet resistance and reduces recombination.

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A method to manufacture solar cells with reduced dopant spread in the emitter region for improved conversion efficiency. The method involves laser doping, oxidation, and grid printing steps. The laser doping is done at speeds of 10000-50000 mm/s and frequencies of 100-300 kHz to form heavily doped regions. After doping, oxidation at 600-1200 seconds and 680-750°C is performed to protect the doped regions. Grid lines are printed on the cell front and back after oxidation to make ohmic contact with the doped regions.

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Method for manufacturing a solar cell with improved efficiency by selectively doping the emitter region of the cell instead of the whole surface. The method involves applying boron paste to a specific area on the cell surface, then solidifying it to form a heavily doped region. This selective doping reduces surface recombination and improves short-circuit current, fill factor, and conversion efficiency compared to uniform doping. The solar cell can also have other features like passivation layers, polysilicon layers, and electrodes to further improve performance.

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Solar cell manufacturing method that improves electrical performance by using laser doping instead of high-temperature diffusion. The method involves forming an emitter layer with doping on the front surface of a silicon wafer, then forming passivation layers on the emitter and back surfaces. Before or after forming the passivation layers, laser bombardment is performed on the emitter to activate the doping. This reduces saturation current density and surface heating compared to high-temperature diffusion while providing enhanced conductivity and hidden open-circuit voltage.

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Solar cell manufacturing process that enables high-efficiency back contact solar cells through a novel multi-layer doping approach. The process involves forming a tunnel oxide on the semiconductor substrate, creating a first doped layer with a first conductivity type dopant, applying a mask to the doped layer, and doping a second doped layer with a second conductivity type dopant. The process incorporates laser-induced doping of the second doped layer, creating a laser-induced pattern that separates the first doped region from the second doped regions. The process also includes trenching, passivation, and patterning steps to create the laser-induced pattern. This multi-layer doping approach enables high-efficiency solar cells with improved performance characteristics.

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Solar cell manufacturing process that enables efficient production of solar cells through laser doping. The process involves forming a tunnel oxide on the semiconductor substrate, doping the oxide with a first conductivity type dopant, creating a mask, and using a laser in a gas atmosphere containing a dopant of the second conductivity type to dope specific regions of the doped layer. The laser selectively targets regions of the doped layer, creating interdigitated contacts while maintaining the doping profile. This approach enables the production of solar cells with improved efficiency and reduced manufacturing time compared to traditional doping methods.

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Manufacturing method for a solar cell doping structure that avoids high-temperature processes. The method uses laser doping to create the p-n junction instead of the traditional high-temperature diffusion process. The steps involve: 1) Preparing the silicon substrate with a thin layer of doped material. 2) Scanning a focused laser beam over the substrate to create the p-n junction without melting or damaging the silicon. This avoids the high temperatures needed for diffusion. The laser power and pulse duration are adjusted to control the dopant concentration.

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Preparation method for laser-doped amorphous silicon HBC solar cells to improve efficiency and reduce manufacturing costs. The method involves cleaning a textured silicon wafer with a specific solution and temperature to create a pyramid textured surface with 10% reflectivity. The textured wafer is then laser-doped with amorphous silicon to create the HBC solar cell. The textured surface increases light absorption and reduces reflection compared to flat surfaces, improving cell efficiency. The specific cleaning solution and texturing conditions optimize the surface roughness for laser doping.

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A method for making laser-doped selective emitter solar cells by selectively doping the silicon wafer surface during the fabrication process. The method involves a multi-step process that combines acid etching with selective doping, followed by surface treatment to enhance contact quality. The acid etching step removes the silicon dioxide layer and back junction, while the selective doping step creates a uniform interface between the N-type and P-type semiconductor regions. The surface treatment step further improves contact by removing impurities and creating a textured surface. This integrated approach enables the creation of high-quality laser-doped selective emitter solar cells with improved contact properties and reduced surface defects.

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Solar cell with enhanced efficiency through controlled dopant distribution. The cell features a semiconductor substrate with a passivation layer, a conductive region formed on the passivation layer, and an electrode connected to the conductive region. A doping profile is created in the semiconductor substrate, with the doping concentration of the conductive dopant decreasing continuously from the passivation layer to the conductive region and then to the electrode. This continuous dopant profile enables carrier flow through the semiconductor material while maintaining optimal band alignment. The doping profile is achieved through a laser-induced doping process that creates a uniform concentration gradient across the semiconductor substrate.

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Improved doping process for silicon substrates to enhance uniformity of square resistance in solar cells. The process involves controlled diffusion in thermal diffusion furnaces to deposit dopants at specific locations, while maintaining uniform dopant distribution throughout the wafer. This approach prevents the characteristic "center-edge" distribution of square resistance typically observed in diffusion processes, resulting in more consistent electrical properties across the wafer. The method enables precise control over dopant distribution patterns, enabling the production of high-performance solar cells with improved uniformity.

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A method for creating selective regions in solar cells through selective doping using laser-induced diffusion. The method involves doping the silicon substrate with dopants, followed by laser-induced diffusion through a spinner system. The laser radiation selectively targets the metal mesh regions, creating a region of high doping concentration. The dopant liquid is then applied to the substrate surface, where it spreads evenly through the spinner system, forming a region of high doping concentration. The spinner system is then followed by hydrofluoric acid treatment to remove silicates and create a clean surface for subsequent processing steps. This process enables the creation of selective regions in solar cells that can be selectively doped to enhance carrier recombination and efficiency.

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A method to prevent power loss in solar cells during laser splitting by selectively creating a high doping concentration region on the side surface. The method involves preparing a solar cell with a split face having a first conductivity type and a second face with different conductivity types facing opposite directions. The first face is selectively doped with a dopant gas during the laser splitting process, creating a high doping concentration region on the side surface. This region is then selectively created on the side surface during the manufacturing process by irradiating the side surface with a laser while supplying the dopant gas. The high doping concentration region acts as a field-effect passivation layer, preventing carrier recombination and reducing internal potential loss during splitting.

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A doping method for solar cells that enables efficient doping of high-efficiency battery emitters and back surface fields through a single process. The method employs a mixed solution of KOH and H2O2 to remove damaged layers, with optimized conditions of 50°C to 85°C. This integrated doping approach eliminates the need for separate high-temperature processes for emitter and back surface field doping, enabling uniform doping across the solar cell.

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Method for improving solar cell efficiency through selective laser doping of the emission junction. The method involves selectively irradiating the emission junction with a laser to create a selectively doped region, then etching the irradiated area to create a selectively doped region with higher doping concentration than the non-irradiated area. This selective doping enables independent adjustment of the doping concentrations in the irradiated and non-irradiated regions, thereby improving the solar cell's fill factor and conversion efficiency.

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