Photovoltaic cell and photovoltaic module

Abstract

The photovoltaic cell comprises a silicon substrate, a doping layer is arranged on the surface of the silicon substrate, a PN junction is formed on the silicon substrate, and when sunlight irradiates the silicon substrate, electric energy can be generated. The doping layer is provided with a grid line, and the grid line is electrically connected with the doping layer, and can collect and export electric energy generated in the doping layer. The grid line is formed by sintering conductive paste, after the conductive paste is sintered into the grid line, first laser is radiated to the grid line, the radiation depth of the first laser on the photovoltaic cell is not larger than 2 microns, at the moment, glass oxide in the grid line is of a compact net-shaped structure, the local field enhancement effect of metal particles is restrained, and no characteristic peak exists in a Raman spectrum shown by the grid line. The quality state of the grid line is indicated through the state of the spectral analysis grid line formed by Raman detection, and the method can reduce the possibility of damage to the grid line in the detection process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to a photovoltaic cell and a photovoltaic module. BACKGROUND

[0002] The surface of the silicon substrate is provided with a doped layer, so that the photovoltaic cell converts absorbed solar energy into electrical energy by photovoltaic effect. The doped layer is provided with a grid line, which can collect and export the electrical energy generated by the silicon substrate. With the use of the photovoltaic cell, the grid line gradually degrades, and the doped layer appears ultraviolet-induced decay. Therefore, the state of the doped layer and the grid line will affect the power generation efficiency of the photovoltaic cell. At present, the detection methods of the photovoltaic cell include macroscopic testing of the whole device and microscopic observation of the nanoscale structure. The macroscopic testing includes I-V testing, transfer length method and photoluminescence, which cannot detect the structure of the doped layer and the grid line. The microscopic observation of the nanoscale structure mainly uses optical microscopes or laboratory scanning electron microscopes, which need to damage the photovoltaic cell. SUMMARY

[0003] The present application relates to a photovoltaic cell and a photovoltaic module to solve the problem that the state of the grid line is not convenient to monitor.

[0004] In a first aspect, the present application relates to a photovoltaic cell, which comprises: a silicon substrate, the surface of the silicon substrate being provided with a doped layer, the doped layer being provided with a grid line, the grid line being electrically connected with the doped layer; wherein the grid line is sintered from conductive paste, a first laser is radiated to the grid line after the conductive paste is sintered into the grid line, the radiation depth of the first laser on the photovoltaic cell is not greater than 2um, the glass oxide in the grid line is a dense network structure, and the grid line shows no characteristic peak in Raman spectrum.

[0005] In a possible embodiment, the wave number range of the Raman spectrum is 100cm -1 to 3200cm -1 .

[0006] In a possible embodiment, the silver particles in the grid line have a dense lattice structure, and the grid line shows no characteristic peak in the Raman spectrum in the range of 200cm -1 to 400cm -1 .

[0007] In a possible embodiment, there is no interface phonon coupling between the silver particles in the grid line and the silicon substrate, and the grid line shows no characteristic peak in the Raman spectrum in the range of 100cm -1 to 200cm -1 .

[0008] In a possible embodiment, after sintering, the additive in the grid line volatilizes, and the grid line exhibits no characteristic peaks in the Raman spectrum in the range of 600 cm -1 to 1800 cm -1 .

[0009] In a possible embodiment, after the grid line is used for a preset length of time or is subjected to artificial degradation treatment, the amplitude of lattice vibration of silver particles in the grid line is greater than the amplitude of lattice vibration of silver particles when the grid line is in an initial state, and the grid line exhibits characteristic peaks in the Raman spectrum in the range of 400 cm -1 to 1000 cm -1 .

[0010] In a possible embodiment, after the grid line is used for a preset length of time or is subjected to artificial degradation treatment, the grid line has carbon accumulation, and the grid line exhibits characteristic peaks in the Raman spectrum in the range of 1100 cm -1 to 1700 cm -1 .

[0011] In a possible embodiment, after the grid line is used for a length of time less than a preset length of time, the grid line has silver oxide, and the grid line exhibits characteristic peaks in the Raman spectrum in the range of 150 cm -1 to 280 cm -1 .

[0012] In a possible embodiment, the wavelength of the first laser ranges from 400 nm to 2000 nm.

[0013] In a possible embodiment, the doped layer has a silicon-boron bond, a second laser is radiated to the doped layer, and the radiation depth is less than 30 nm; before the photovoltaic cell is subjected to ultraviolet-induced degradation, the silicon-boron bond is intact, the doped layer has a first characteristic peak in the Raman spectrum, and after the photovoltaic cell is subjected to ultraviolet-induced degradation, the silicon-boron bond is broken, and the doped layer has a second characteristic peak in the Raman spectrum; the wave number of the second characteristic peak is greater than that of the first characteristic peak, and the half-peak width of the second characteristic peak is less than that of the first characteristic peak.

[0014] In a second aspect, the present application also relates to a photovoltaic module, which comprises a first cover plate, a first adhesive film, a cell piece group, a second adhesive film, and a second cover plate, the cell piece group comprises a plurality of photovoltaic cells, and the photovoltaic cell is the photovoltaic cell in any one of the above aspects.

[0015] The beneficial effect of the present application is that the silicon substrate surface is provided with a doped layer, a PN junction is formed on the silicon substrate, and when sunlight irradiates the silicon substrate, electrical energy can be generated. The doped layer is provided with a grid line, the grid line is electrically connected with the doped layer, and the electrical energy generated in the doped layer can be collected and led out. The grid line is sintered from conductive paste, and when the conductive paste is sintered into the grid line, the first laser is radiated to the grid line, the radiation depth of the first laser on the photovoltaic cell is not greater than 2 μm, at this time, the glass oxide in the grid line is a dense network structure, which inhibits the local field enhancement effect of the metal particles, and the grid line does not have a characteristic peak in the Raman spectrum. The state of the grid line is analyzed by the spectrum formed by Raman detection, which can reduce the possibility of damage to the grid line during detection. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 The structure schematic diagram of one embodiment of the photovoltaic cell provided by the embodiments of the present application; Figure 2 The Raman curves of the grid line in the photovoltaic cell provided by the embodiments of the present application in different states; Figure 3 The schematic diagram of the carbon content of the grid line in the photovoltaic cell provided by the embodiments of the present application when the grid line is in an initial state; Figure 4 The schematic diagram of the carbon content of the grid line in the photovoltaic cell provided by the embodiments of the present application after the photovoltaic cell is used for a preset time or after artificial accelerated degradation; Figure 5 The Raman spectra of the doped layer of the photovoltaic cell provided by the embodiments of the present application before and after long-time irradiation of sunlight; Figure 6 The wave number of the characteristic peak in the Raman spectrum of the doped layer of the photovoltaic cell provided by the embodiments of the present application before and after long-time irradiation of sunlight; Figure 7 The half-peak width of the characteristic peak in the Raman spectrum of the doped layer of the photovoltaic cell provided by the embodiments of the present application before and after long-time irradiation of sunlight; Figure 8 The curve of the change of the wave number of the characteristic peak in the Raman spectrum of the doped layer of the photovoltaic cell provided by the embodiments of the present application in an ultraviolet light environment with irradiation time; Figure 9 The curve of the change of the half-peak width of the characteristic peak in the Raman spectrum of the doped layer of the photovoltaic cell provided by the embodiments of the present application in an ultraviolet light environment with irradiation time; Figure 10 A structural schematic diagram of a photovoltaic module provided in an embodiment of the present application.

[0018] Reference signs: 1-silicon substrate; 11-doped layer; 12-passivation layer; 2-grid line; 3-first cover plate; 4-first adhesive film; 5-cell group; 6-second adhesive film; 7-second cover plate. DETAILED DESCRIPTION

[0019] In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the drawings.

[0020] It should be clear that the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0021] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0022] It should be understood that the term "and / or" used herein is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0023] As Figure 1 shown, the present application provides a photovoltaic cell, which includes a silicon substrate 1, a doped layer 11 is arranged on the silicon substrate 1, a PN junction is formed on the silicon substrate 1, after the sunlight irradiates to the photovoltaic cell, the holes of the N-type semiconductor in the PN junction move to the P-type region, and the electrons in the P-type region move to the N-type region, thereby forming the current from the N-type region to the P-type region, forming the potential difference in the PN junction, forming the power supply. The grid line 2 is arranged on the doped layer 11, the grid line 2 is a conductive material, which can be electrically connected with the doped layer 11, thereby collecting the electric energy generated in the doped layer 11, and guiding the electric energy out of the photovoltaic cell through the grid line 2.

[0024] The structure of the battery piece is not limited in the present application, and the types of the battery piece include but are not limited to a passivated emitter rear cell (PERC), a tunnel oxide passivated contact (TOPCon), a heterojunction with intrinsic thin-film (HJT), an interdigitated back contact (IBC), a perovskite cell, etc. Figure 1 TOPCon cell is taken as an example.

[0025] For the PERC cell, along the thickness direction, the PERC cell includes a front surface metal silver electrode, a front surface silicon nitride passivation layer 12, a phosphorus layer emitter, a P-type base silicon layer, a local aluminum back field, a metal aluminum back electrode, and a back passivation layer 12 (Al2O3 / SiNx) in sequence.

[0026] For the TOPCon cell, along the thickness direction, the TOPCon cell includes a metal silver electrode, a front surface silicon nitride passivation layer 12, a boron-doped emitter, an N-type base silicon layer, a diffusion-doped layer 11, an ultrathin silicon oxide, a doped polysilicon, silicon nitride, and a metal silver electrode in sequence. The back surface of the cell is composed of an ultrathin silicon oxide layer (1 nm~2 nm) and a phosphorus-doped microcrystalline amorphous Si thin film, which together form a passivation contact structure. This structure can block the recombination of minority carriers, improve the open-circuit voltage and short-circuit current of the cell. The ultrathin oxide layer can enable the tunneling of majority electrons into the polysilicon layer while blocking the recombination of minority carriers. The good passivation effect of the ultrathin silicon oxide and the heavily doped silicon thin film causes the energy band of the silicon wafer surface to bend, thereby forming a field passivation effect. The probability of electron tunneling is greatly increased, the contact resistance is reduced, the open-circuit voltage and short-circuit current of the cell are improved, and thus the conversion efficiency of the cell is improved.

[0027] For the HJT cell, along the thickness direction, the HJT cell includes a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode in sequence.

[0028] For the IBC cell, along its thickness direction, the IBC cell comprises, in sequence, a silicon nitride anti-reflection layer, an N+ front surface field, an N-type base silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a metal silver electrode. The IBC cell uses ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth, and the cell front surface is not blocked by the grid line 2, which can eliminate the shading current loss of the metal electrode, realize the maximum utilization of incident photons, and increase the short-circuit current of the conventional solar cell by about 7%; due to the back contact structure, the grid line 2 blocking problem does not need to be considered, and the proportion of the grid line 2 can be appropriately widened, thereby reducing the series resistance and having a high fill factor; the surface passivation and light trapping structure can be optimally designed to obtain a lower front surface recombination rate and surface reflection.

[0029] For the perovskite cell, along its thickness direction, the perovskite cell comprises, in sequence, a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite material has a high light absorption coefficient and a long carrier diffusion distance. After the absorbed photons are converted into electrons, the electrons are easily collected by the electrode and have less loss, so perovskite can generate higher photovoltage and current, and thus perovskite exhibits higher photoelectric conversion efficiency.

[0030] The grid line 2 in the photovoltaic cell is formed by sintering the conductive paste transferred to the silicon substrate 1. The conductive paste includes silver powder, glass oxide, and an organic carrier. The silver powder makes the conductive paste have good conductivity after sintering. The glass oxide can form a chemical bond with the silicon substrate 1 through high-temperature sintering, thereby enhancing the adhesion of the grid line 2 and improving the strength of the grid line 2. The glass oxide can also optimize the ohmic contact performance between the grid line 2 and the silicon substrate 1, and reduce the resistance between the grid line 2 and the silicon substrate 1. The organic carrier enables the other components in the conductive paste to be uniformly mixed, and also adjusts the fluidity of the conductive paste, facilitating the transfer of the conductive paste. The organic carrier will gradually volatilize and consume during the sintering process. After the grid line 2 is used for a predetermined length of time or is artificially degraded, the organic part in the grid line 2 that has not been consumed will evolve into carbon material, gradually reducing the conductivity of the grid line 2.

[0031] The Raman detection is performed on the grid line 2 after the conductive paste is sintered, and a Raman spectrum is obtained. Through analysis of the Raman spectrum, the state of the grid line 2 can be obtained, the sintering effect of the conductive paste can be judged, and the sintering parameters can be adjusted. The content of glass oxide in the conductive paste will affect the Raman signal of the conductive paste. The higher the content of glass oxide in the conductive paste, the stronger the Raman signal of the paste. After the conductive paste is sintered at high temperature to form a grid line, the glass oxide forms a dense network structure, which can inhibit the local field enhancement effect of silver particles, and thus can reduce the Raman signal of the grid line. The Raman detection is performed on the grid line 2 after the grid line 2 is used for a preset time or is artificially degraded, and a Raman spectrum is obtained. Through analysis of the Raman spectrum, the state of the grid line 2 can be obtained, and the degradation degree of the grid line 2 can be determined. The Raman detection analyzes the state of the grid line 2 through the spectrum formed by the scattering of the first laser light by the grid line 2, and can reduce the damage to the grid line 2 during the detection process.

[0032] When the Raman detection is performed on the grid line 2, the Raman spectrometer emits a first laser to the grid line 2, and the components in the grid line 2 will undergo Raman reflection to form a Raman spectrum. In one possible embodiment, the first laser emitted by the Raman spectrometer to the grid line 2 is a visible band laser and a near-infrared band laser, and the wavelength range is 400 nm to 2000 nm.

[0033] As the grid line 2 degrades, carbon materials will accumulate in the grid line. The carbon material is an accumulation behavior throughout the grid line 2. Therefore, the wavelength of the first laser can be in the range of 400 nm to 2000 nm, and specifically can be 442 nm, 514 nm, 532 nm, 633 nm, 785 nm, etc. For example, the wavelength of the first laser is 514 nm, which can make the first laser spot on the grid line 2 smaller, so that the spatial resolution can reach a sub-micron level, and the state of the lattice in the grid line 2 can be easily detected. For inorganic materials such as silicon, aluminum oxide, and metal oxides in the conductive paste and / or the grid line, the wavelength of the first laser is 514 nm, which can also reduce the possibility of fluorescence interference, and has a better signal-to-noise ratio. As the wavelength of the first laser increases, less surface information of the conductive paste and / or the grid line is obtained through Raman detection.

[0034] In one possible embodiment, the power of the first laser emitted by the Raman spectrometer is 24 mW to 40 mW.

[0035] The Raman detection analyzes the state of the grid line 2 through the spectrum formed by the scattering of the first laser light by the grid line 2. The power of the first laser emitted by the Raman spectrometer is greater than or equal to 24 mW, which can improve the intensity of the signal and the signal-to-noise ratio. After the conductive paste is sintered into a grid line 2, the main component is silver particles, which makes the reflectivity of the grid line 2 to the first laser high. The power of the first laser emitted by the Raman spectrometer is less than or equal to 40 mW, and the low power of the first laser can reduce the possibility of damage to the sample by the first laser.

[0036] In a possible embodiment, the first laser emitted by the Raman spectrometer has a penetration depth on the photovoltaic cell of no more than 2 μm.

[0037] The silicon substrate 1 is provided with a doped layer 11, which forms a PN junction on the silicon substrate 1 to enable the photovoltaic cell to convert sunlight into electrical energy. The thickness of the doped layer 11 can be 2 nm to 1 μm. The doped layer 11 is provided with a passivation layer 12, which can improve the passivation effect of the surface of the silicon substrate 1, reduce the recombination loss of carriers, prolong the carrier lifetime, optimize the charge transport, and the like, thereby improving the power generation efficiency of the photovoltaic cell. The thickness of the passivation layer 12 can be 5 nm to 150 nm. The grid line 2 protrudes from the surface of the passivation layer 12 and can be electrically connected to the doped layer 11. The first laser for Raman detection has a penetration depth on the surface of the photovoltaic cell of no more than 2 μm, so that the Raman detection can detect the state of the contact position of the grid line 2 with the passivation layer 12 and the state of the contact position of the grid line 2 with the doped layer 11.

[0038] As shown in FIG. 1, Figure 2 in a possible embodiment, the wave number range of the Raman spectrum is 100 cm -1 to 3200 cm -1 .

[0039] Different components have different characteristic peak positions in the Raman spectrum. The wider the wave number range of the Raman spectrum, the more information can be obtained. The conductive effect of the grid line 2 in the photovoltaic cell is related to the state of the silver particles and the carbon content in the grid line 2. By observing whether a characteristic peak appears in the range of 100 cm -1 to 3200 cm -1 , the state of the grid line 2 can be analyzed. Figure 2 Curve (1) is the Raman spectrum of the grid line 2 after sintering. After the conductive paste is sintered to form the grid line 2, the conductive paste is metallized, and the Raman spectrum of the grid line 2 has no characteristic peak in the above range. Figure 2 Curve (2) is the Raman spectrum of the grid line 2 after a short period of use, the use time being less than a preset time, or after a slight artificial degradation treatment. At this time, a characteristic peak has appeared in the Raman curve, and the power generation efficiency of the photovoltaic cell is reduced but the photovoltaic cell can still be used normally. Curve (3) is the Raman spectrum of the grid line after use for a preset time or artificial degradation. As carbon-related materials are precipitated, the characteristic peak in the Raman curve is obvious at this time, and the power generation efficiency of the photovoltaic cell is severely reduced, and the photovoltaic cell cannot be used normally. The three curves in curve (2) and curve (3) are the Raman spectra of three grid lines in the photovoltaic cell.

[0040] The Raman spectrum of the grid line 2 includes a low-frequency range, a medium-frequency range, and a high-frequency range. The low-frequency range is 100 cm -1 to 600 cm -1The mid-frequency range is 600cm. -1 Up to 1800cm -1 The high-frequency range is 1800cm. -1 Up to 3500cm -1 .

[0041] 100 cm⁻¹ in Raman spectra -1 Up to 600cm -1 The spectral curves in the low-frequency range can be used to analyze the state of the silver particles in grating line 2.

[0042] During photovoltaic (PV) cell operation, the grid line 2 comes into contact with air, and micropores exist within it. In humid environments, this accelerates oxidation of the grid line 2, causing the silver particles within it to oxidize into silver oxide. Silver oxide has a higher conductivity than the resistivity of silver particles, leading to a decrease in the conductivity of the grid line 2. The weaker bonding between silver oxide and the silicon substrate 1 increases the contact resistance between the grid line 2 and the silicon substrate 1, further reducing the PV cell's power generation efficiency. The porous nature of silver oxide makes the grid line 2 prone to cracking and detachment after the silver particles are oxidized, damaging the PV cell. In humid and hot environments, silver oxide may release silver ions, which can diffuse through the passivation layer 12 into the silicon wafer, forming recombination centers and increasing the carrier recombination rate, thus reducing carrier lifetime. In PV modules, encapsulants are applied to both sides of the PV cell. When the encapsulant is EVA, silver oxide reacts chemically with the encapsulant, releasing sodium ions, which exacerbates the PID (Potential Influence of Degradation) of the PV module. Raman spectroscopy at 150 cm⁻¹ further contributes to this problem. -1 Up to 280cm -1 The spectral curves within the range can be analyzed to determine whether grating line 2 has been oxidized to form silver oxide. For example... Figure 2 As shown, curve (1) is the Raman spectrum of grating line 2 after sintering. At this time, grating line 2 is not oxidized, and the spectrum is at 150 cm⁻¹. -1 Up to 280cm -1 No characteristic peaks are observed within the range. A peak at 150 cm⁻¹ can be seen in curve (2). -1 Up to 280cm -1 It has characteristic peaks within the range. As gate line 2 continues to degrade, carbon in gate line 2 continuously accumulates, and the resulting characteristic peaks overlap with the characteristic peaks formed by silver oxide.

[0043] Through the 200 cm⁻¹ Raman spectrum -1 Up to 400cm -1 The spectral curves within the specified range can be used to analyze the lattice vibration modes of silver particles in grating line 2. The variations in characteristic peaks are related to the size, grain orientation, or stress state of the silver particles. After the conductive paste is sintered into grating line 2, the silver particles in the conductive paste undergo diffusion bonding, reducing grain boundaries and causing the lattice vibration frequencies to become more monotonic. If the Raman spectrum of grating line 2 is within 200 cm⁻¹... -1 Up to 400cm-1 The characteristic peak in the range of 200cm-1 to 400cm-1 in the Raman spectrum of the grid line 2 indicates that the amplitude of the lattice vibration of the silver particles in the grid line 2 is large. The large amplitude of the lattice vibration of the silver particles can enhance the electron scattering effect, thereby increasing the resistance loss in the grid line 2, and can also affect the alloying reaction at the interface between the silver particles and the silicon substrate 1, thereby increasing the contact resistance between the grid line 2 and the silicon substrate 1, and thereby reducing the power generation efficiency of the photovoltaic cell.

[0044] The conductive paste can be sintered and solidified by a laser enhanced contact optimization technology. After the conductive paste is transferred to the silicon substrate 1, the silicon substrate 1 is placed on a support table in a sintering and solidification device, and a plurality of probes are also arranged on the support table, so that the probes are in contact with the ends of the conductive paste. During the sintering process of the conductive paste, the sintering and solidification device emits a sintering laser to the silicon substrate 1, and uses the photoluminescence phenomenon to excite the charge carriers in the silicon substrate 1. At the same time, a deflection voltage is applied through the probes to cause local current to induce sintering, so that the silver particles in the conductive paste and the silicon substrate 1 diffuse with each other, which can reduce the contact resistance between the grid line 2 and the silicon substrate 1, and is conducive to improving the power generation efficiency of the photovoltaic cell. By the above-mentioned sintering and solidification of the conductive paste, the temperature during solidification can be reduced, and the damage to the passivation layer 12 can be reduced, which is conducive to improving the open circuit voltage of the photovoltaic cell. The intensity of the sintering laser, the irradiation time, the intensity of the deflection voltage and other factors in the above-mentioned sintering and solidification process can affect the rearrangement process of the silver particles in the conductive paste. If the Raman spectrum of the grid line 2 after sintering has a characteristic peak in the range of 200cm-1 to 400cm-1, one or more of the parameters of the intensity of the sintering laser, the irradiation time, and the intensity of the deflection voltage in the sintering and solidification process can be adjusted to adjust the rearrangement process of the silver particles in the conductive paste, so as to reduce the lattice vibration of the silver particles in the grid line 2 after sintering. -1 -1 The conductive paste can be sintered and solidified by a laser enhanced contact optimization technology. After the conductive paste is transferred to the silicon substrate 1, the silicon substrate 1 is placed on a support table in a sintering and solidification device, and a plurality of probes are also arranged on the support table, so that the probes are in contact with the ends of the conductive paste. During the sintering process of the conductive paste, the sintering and solidification device emits a sintering laser to the silicon substrate 1, and uses the photoluminescence phenomenon to excite the charge carriers in the silicon substrate 1. At the same time, a deflection voltage is applied through the probes to cause local current to induce sintering, so that the silver particles in the conductive paste and the silicon substrate 1 diffuse with each other, which can reduce the contact resistance between the grid line 2 and the silicon substrate 1, and is conducive to improving the power generation efficiency of the photovoltaic cell. By the above-mentioned sintering and solidification of the conductive paste, the temperature during solidification can be reduced, and the damage to the passivation layer 12 can be reduced, which is conducive to improving the open circuit voltage of the photovoltaic cell. The intensity of the sintering laser, the irradiation time, the intensity of the deflection voltage and other factors in the above-mentioned sintering and solidification process can affect the rearrangement process of the silver particles in the conductive paste. If the Raman spectrum of the grid line 2 after sintering has a characteristic peak in the range of 200cm-1 to 400cm-1, one or more of the parameters of the intensity of the sintering laser, the irradiation time, and the intensity of the deflection voltage in the sintering and solidification process can be adjusted to adjust the rearrangement process of the silver particles in the conductive paste, so as to reduce the lattice vibration of the silver particles in the grid line 2 after sintering.

[0045] The conductive paste can also be sintered by high temperature. After the conductive paste is transferred to the silicon substrate 1, it is placed in the cavity of a sintering device. The photovoltaic cell is rapidly heated by an infrared lamp tube, the glass oxide in the conductive paste is melted, the passivation layer 12 is etched, and the silver particles in the conductive paste form an ohmic contact with the doped layer 11. The temperature change curve in the cavity of the sintering device in the above-mentioned sintering process can affect the quality of the grid line 2 after sintering. If the Raman spectrum of the grid line 2 after sintering has a characteristic peak in the range of 200cm-1 to 400cm-1, the temperature curve in the cavity of the sintering device can be adjusted to improve the yield of the grid line 2 after sintering. -1 -1 The conductive paste can be sintered and solidified by a laser enhanced contact optimization technology. After the conductive paste is transferred to the silicon substrate 1, the silicon substrate 1 is placed on a support table in a sintering and solidification device, and a plurality of probes are also arranged on the support table, so that the probes are in contact with the ends of the conductive paste. During the sintering process of the conductive paste, the sintering and solidification device emits a sintering laser to the silicon substrate 1, and uses the photoluminescence phenomenon to excite the charge carriers in the silicon substrate 1. At the same time, a deflection voltage is applied through the probes to cause local current to induce sintering, so that the silver particles in the conductive paste and the silicon substrate 1 diffuse with each other, which can reduce the contact resistance between the grid line 2 and the silicon substrate 1, and is conducive to improving the power generation efficiency of the photovoltaic cell. By the above-mentioned sintering and solidification of the conductive paste, the temperature during solidification can be reduced, and the damage to the passivation layer 12 can be reduced, which is conducive to improving the open circuit voltage of the photovoltaic cell. The intensity of the sintering laser, the irradiation time, the intensity of the deflection voltage and other factors in the above-mentioned sintering and solidification process can affect the rearrangement process of the silver particles in the conductive paste. If the Raman spectrum of the grid line 2 after sintering has a characteristic peak in the range of 200cm-1 to 400cm-1, one or more of the parameters of the intensity of the sintering laser, the irradiation time, and the intensity of the deflection voltage in the sintering and solidification process can be adjusted to adjust the rearrangement process of the silver particles in the conductive paste, so as to reduce the lattice vibration of the silver particles in the grid line 2 after sintering.

[0046] As shown in curve (1) in Figure 2 After the conductive paste is sintered into the grid line 2, the Raman spectrum of the grid line 2 has a characteristic peak in the range of 200cm-1 to 400cm-1. -1 -1 ​​​If there is no characteristic peak in the range of 100cm Figure 2 -200cm -1 -1, the silver particle lattice in the grid line 2 is relatively dense, the contact resistance between the grid line 2 and the silicon substrate 1 is small, and the power generation efficiency of the photovoltaic cell is high. If -1 a characteristic peak appears in the range of 200cm -1 -400cm -1 , the vibration amplitude of the silver particle lattice in the grid line 2 increases, resulting in an increase in the resistance between the grid line 2 and the silicon substrate 1, which reduces the power generation efficiency of the photovoltaic cell.

[0047] After the conductive paste is sintered into the grid line 2, interface phonon coupling may occur at the interface where the silver particles in the grid line 2 contact the silicon substrate 1 or other materials. Interface phonon coupling can affect the photovoltaic cell by reducing the transport efficiency of carriers, increasing recombination loss, degrading thermodynamic performance, and reducing optical performance. Interface phonon coupling in the grid line 2 can exacerbate the heat dissipation effect of carriers at the contact interface, resulting in a decrease in mobility. For example, after the conductive paste is sintered into the grid line 2, if there is a lattice mismatch at the silver-silicon alloy interface formed between the grid line 2 and the silicon substrate 1, phonon coupling can hinder the directional flow of carriers, increasing the series resistance. In the interface phonon coupling phenomenon, phonon energy transfer can cause local lattice vibration, which can destroy the stability of the electrical contact between the grid line 2 and the silicon substrate 1, resulting in a local increase in contact resistance. Phonon interface coupling can amplify the vibration amplitude of interface defects (such as dangling bonds and dislocations), which can become recombination centers, further increasing the surface recombination rate and reducing the open-circuit voltage. The passivation layer can be aluminum oxide, silicon nitride, etc. The phonon vibration mode of the grid line 2 does not match the phonon vibration mode of the passivation layer 12, which can cause cracks in the passivation layer 12, accelerate carrier recombination, and further reduce the power generation efficiency of the photovoltaic cell. Phonon coupling can cause the conversion of phonon energy to heat energy at the interface, forming local hot spots that can cause thermal expansion differences and increase the rate of electrode peeling. Interface phonon coupling can cause structural fatigue of the contact interface between the grid line 2 and the silicon substrate 1, making the grid line 2 prone to breakage. The side of the silicon substrate 1 where the grid line 2 is provided can be a textured structure, and the grid line 2 is provided on the textured structure. Phonon coupling at the interface between the grid line 2 and the silicon substrate 1 can cause changes in the textured structure, which can further reduce the light absorption efficiency of the photovoltaic cell.

[0048] The spectrum curve in the range of 100cm -1 -200cm -1 in the Raman spectrum of the sintered grid line 2 can be used to analyze whether the silver particles in the grid line 2 are in interface phonon coupling with the silicon substrate 1 or other materials. If there is no characteristic peak in the range of 100cm -1 -200cm -1no characteristic peak in the range of 100cm -1 to 200cm -1 indicates that there is no interface phonon coupling between the grid line 2 and the silicon substrate 1 or other materials, and the photovoltaic cell has high carrier transport efficiency, low recombination loss, good thermodynamic performance, and strong optical performance. If a characteristic peak appears in the range of 100cm -1 to 200cm -1 , it indicates that a chemical reaction occurs at the interface between the silver particles in the grid line 2 and the silicon substrate 1, or at the interface between the silver particles and other materials, and the parameters of the conductive paste sintering process need to be adjusted to improve the yield of the grid line 2.

[0049] During the corrosion of the grid line 2, as the grid line 2 is oxidized and carbon residues are introduced into the grid line, the structure of the contact surface between the grid line 2 and the silicon substrate 1 becomes rougher, enhancing phonon scattering and causing energy transfer to be blocked. The superposition of vibration peaks of different materials in the grid line 2 forms a complex coupling spectrum, which strengthens the interface phonon coupling between the grid line 2 and the silicon substrate 1, and reduces the conductivity of the grid line 2.

[0050] As shown in curve (1) in Figure 2 , after the conductive paste is sintered into the grid line 2, there is no characteristic peak in the range of 100cm -1 to 200cm -1 in the Raman spectrum of the grid line 2, and the photovoltaic cell has high carrier transport efficiency, low recombination loss, good thermodynamic performance, and strong optical performance, as shown in curve (3) in Figure 2 , the Raman spectrum obtained during the use of the photovoltaic cell for a predetermined time or after artificial degradation process, a characteristic peak appears in the range of 100cm -1 to 200cm -1 , and the silver particles in the grid line 2 and the silicon substrate 1 contact the interface phonon coupling, resulting in a decrease in the power generation efficiency of the photovoltaic cell.

[0051] The organic carrier in the conductive paste contains solvents and resins, which can uniformly mix the silver powder and glass oxides in the conductive paste, and can adjust the fluidity of the conductive paste, so that the conductive paste can be transferred to the silicon substrate 1. During the sintering process, the organic solvents and part of the resins in the organic carrier can volatilize, release carbon dioxide and water vapor, and gradually reduce the carbon content in the organic solvent. The remaining resins and additives further carbonize at high temperature, and part of the carbon may react with oxygen to generate carbon monoxide or carbon dioxide, or form carbides with metals. Influenced by the sintering environment, such as temperature control and atmosphere during the sintering process, after sintering is completed, a small amount of carbon residue may be present in the grid line 2, which will affect the conductivity of the grid line 2 and increase the contact resistance between the grid line 2 and the silicon substrate 1, resulting in a decrease in the power generation efficiency of the photovoltaic cell.

[0052] In the Raman spectrum of the grid line 2, the peak at 600cm-1 to 1800 cm -1 , especially 1100 cm -1 to 1700 cm -1 , can analyze the content and state of carbon in the grid line 2.

[0053] As Figure 3 shown, during the sintering of the conductive paste, if the organic carrier is completely volatilized or decomposed, there is no carbon residue in the grid line 2 after sintering, at this time, the spectrum curve in the range of 600 cm -1 to 1800 cm -1 has no characteristic peak, the contact resistance between the grid line 2 and the silicon substrate 1 and the resistance of the grid line 2 itself are small, which is conducive to improving the power generation efficiency of the photovoltaic cell.

[0054] During the sintering of the conductive paste, if the organic carrier is not completely volatilized or decomposed, there is carbon residue in the grid line 2 after sintering, at this time, the spectrum curve in the range of 600 cm -1 to 1800 cm -1 has a characteristic peak, the contact resistance between the grid line 2 and the silicon substrate 1 and the resistance of the grid line 2 itself are large, and the power generation efficiency of the photovoltaic cell is low.

[0055] During the corrosion process of the grid line 2, the D peak at 1350 cm -1 and the G peak at 1580 cm -1 in the Raman spectrum curve can represent the defects and order of the carbon material in the grid line 2. The aging degree of the grid line 2 can be analyzed by the change of the D / G ratio, when the D / G ratio is less than or equal to 1, the influence on the conductive performance of the grid line 2 is small; when the D / G ratio is greater than 1 and less than 1.5, the influence on the conductivity of the grid line 2 is large, at this time, the temperature and other conditions in the sintering process of the conductive paste need to be adjusted to reduce the carbon residue in the grid line 2, and thus improve the conductive effect of the grid line 2; when the D / G ratio is greater than or equal to 1.5, the grid line 2 is seriously aged, and the contact resistance of the grid line 2 is significantly increased or causes an open circuit.

[0056] Some additives in the organic solvent may decompose at a specific temperature during the sintering process of the conductive paste, which will affect the conductive performance of the grid line 2 after sintering, and new Raman characteristic peaks are generated in the range of 1000 cm -1 to 1800 cm -1 .

[0057] As Figure 2 shown in curve (1), in the Raman spectrum of the grid line 2, if there is a characteristic peak in the range of 600 cm -1 to 1800 cm -1If no characteristic peaks are found in the spectral curve within the specified range, it indicates that there is no carbon residue in grating line 2, and grating line 2 has good conductivity. If the conductivity is within 600 cm⁻¹, then... -1 Up to 1800cm -1 If the spectral curve within the range has characteristic peaks, it indicates that there is carbon residue or decomposition products of additives in the grid line 2. It is necessary to adjust the temperature change curve during the curing process of the grid line 2 so that the organic solvent in the conductive paste can evaporate more fully, thereby improving the conductivity of the grid line 2.

[0058] like Figure 4 As shown, the carbon material in grid line 2 will re-aggregate and grow as the photovoltaic cell degrades, forming amorphous carbon, which causes the conductivity of grid line 2 to gradually decrease. After the photovoltaic cell has been used for a preset time or after artificial degradation, such as... Figure 2 As shown in curve (3), the Raman spectrum of grating line 2 at 1100 cm⁻¹ -1 Up to 1700cm -1 Characteristic peaks appear within the range, with the D peak at 1350 cm⁻¹ in the Raman spectrum. -1 And G peak 1580cm -1 It can characterize the defects and order of carbon materials, and the change in the D / G ratio can reveal the aging degree or aggregation behavior of the conductive agent, and thus can analyze whether the grating line 2 can continue to work through Raman spectroscopy.

[0059] As the photovoltaic cell degrades, carbon within the grid line 2 continuously accumulates, forming a two-dimensional stack. This leads to a gradual decrease in the conductivity of the grid line 2. After a predetermined usage period or after artificial degradation, such as... Figure 2 As shown in curve (3), at 2500cm -1 Up to 3200cm -1 It has characteristic peaks within the range.

[0060] After prolonged use, under the influence of light and electric fields, silver particles may undergo electromigration in photovoltaic modules, leading to atomic rearrangement or grain boundary weakening. Over extended periods, oxidation or corrosion within the silver may cause structural degradation at the interface between the grid line 2 and the silicon substrate 1, affecting lattice integrity. Lattice distortion increases the amplitude of lattice vibrations, leading to increased resistance in the grid line 2 and increasing the likelihood of grid line breakage or detachment.

[0061] like Figure 2 As shown in curve (1), when the conductive paste is sintered into grid line 2, grid line 2 is in its initial state, and its Raman spectrum at 400 cm⁻¹... -1 Up to 1000cm -1 No characteristic peaks were observed within the specified range, indicating good metallic properties in grid line 2 and high power generation efficiency in the photovoltaic cell. Raman spectroscopy can detect whether there are lattice changes within grid line 2, such as... Figure 2As shown in the middle curve (3), after the gate line 2 is used for a preset time length or is subjected to artificial degradation treatment, the gate line 2 has a characteristic peak in the range of 400 cm -1 to 1000 cm -1 in the Raman spectrum, which indicates that the crystal lattice of the silver particles in the gate line 2 has changed, resulting in a lower power generation efficiency of the photovoltaic cell.

[0062] After the gate line 2 is used for a preset time length or is subjected to artificial degradation treatment, carbides or other hybrid compounds can also be generated, and new characteristic peaks can also appear in the high-frequency range of the Raman spectrum of the gate line 2.

[0063] After the silicon substrate 1 is doped with boron, a doped layer 11 can be formed on the surface of the silicon substrate 1, and the doped layer 11 has silicon-boron bonds to form a PN junction, so that the photovoltaic cell can generate electric energy after absorbing the energy of sunlight. The doped layer 11 also has silicon-hydrogen bonds, which can reduce the surface defects of the doped layer 11 and improve the photoelectric conversion efficiency of the photovoltaic cell. During the use of the photovoltaic cell, ultraviolet rays can irradiate the doped layer 11, causing the doped layer 11 to undergo ultraviolet-induced decay. After long-time irradiation of the ultraviolet rays, the silicon-hydrogen bonds will be broken, causing the silicon-boron bonds in the doped layer 11 to break, the effect of boron doping in the doped layer 11 to deteriorate, and the photoelectric conversion efficiency of the photovoltaic cell to decrease.

[0064] In one possible embodiment, the Raman spectrometer can emit a second laser to the doped layer 11. The second laser can be ultraviolet light with a wavelength less than or equal to 400 nm, and preferably ultraviolet light with a wavelength of 325 nm and a power of 24 mW. The radiation depth of the second laser is less than 30 nm, and the Raman spectrum of the doped layer 11 can be obtained to determine the state of the silicon-boron bonds in the doped layer 11.

[0065] As shown in the middle curve (3), after the gate line 2 is used for a preset time length or is subjected to artificial degradation treatment, the gate line 2 has a characteristic peak in the range of 400 cm Figure 5 、 Figure 6 and Figure 7As shown, the doped layer 11 on the surface of the silicon substrate 1 of the photovoltaic cell in the control group is not irradiated by sunlight, and neither the silicon-hydrogen bond nor the silicon-boron bond in the doped layer 11 is destroyed, the doping state of the doped layer 11 is good, and the photoelectric conversion efficiency of the photovoltaic cell is high. At this time, the Raman spectrometer emits the second laser to the doped layer 11, and the Raman spectrum of the doped layer 11 is obtained, and the first characteristic peak will appear in the Raman spectrum. The photovoltaic cell in the experimental group is irradiated by sunlight for a long time, and the ultraviolet in the sunlight can irradiate the doped layer 11, destroy the silicon-hydrogen bond in the doped layer 11, break the silicon-hydrogen bond, and further break the silicon-boron bond. The doping state of the doped layer 11 is poor, and the photoelectric conversion efficiency of the photovoltaic cell is reduced. At this time, the Raman spectrometer emits the second laser to the doped layer 11, and the Raman spectrum obtained will appear the second characteristic peak. In the process of ultraviolet-induced attenuation of the doped layer 11, the silicon-boron bond is gradually broken, the Raman peak of the doped layer 11 gradually evolves to the Raman peak before doping, the wave number of the characteristic peak gradually increases, and the half-peak width gradually decreases. Therefore, the wave number of the second characteristic peak is greater than the wave number of the first characteristic peak, and the half-peak width of the second characteristic peak is less than the half-peak width of the first characteristic peak.

[0066] In one possible embodiment, the wave number of the first characteristic peak is 519cm -1 to 520cm -1 , and the half-peak width of the first characteristic peak is 17.5cm -1 to 18.5cm -1 . The wave number of the characteristic peak is 520cm -1 to 521cm -1 , and the half-peak width is 15cm -1 to 16cm -1 .

[0067] The passivation layer 12 is arranged on the side of the doped layer 11 away from the silicon substrate 1, which can reduce the protection of the silicon-hydrogen bond in the doped layer 11, reduce the possibility of breaking the silicon-hydrogen bond in the doped layer 11 after the photovoltaic cell is irradiated by sunlight for a long time, and further improve the service life of the photovoltaic cell. The position and half-peak width of the characteristic peak of the doped layer 11 in the Raman spectrum can be used to judge the time required for the silicon-hydrogen bond in the doped layer 11 to break, and the material, number of layers, thickness and other parameters of the protective layer can be adjusted according to the time required for the silicon-hydrogen bond to break to improve the service life of the photovoltaic cell.

[0068] If the photovoltaic cell is placed under sunlight, the degradation of the grid line 2 and the breaking of the silicon-hydrogen bond in the doped layer 11 require a long time, so the detection period required for recording the state of the photovoltaic cell at different use times by Raman detection is long. Both the degradation of the grid line 2 and the breaking of the silicon-hydrogen bond in the doped layer 11 are greatly affected by ultraviolet light in sunlight, so the photovoltaic cell can be placed in an ultraviolet light environment, the ultraviolet light dose received by the photovoltaic cell can be controlled by the ultraviolet laser intensity, the selection of the objective aperture and the exposure time, and then the length of time that the photovoltaic cell can work under sunlight is calculated by the ultraviolet light dose received by the photovoltaic cell, so as to shorten the detection period.

[0069] As shown in Figure 10 The embodiment of the present application also provides a photovoltaic module, which comprises a first cover plate 3, a first adhesive film 4, a cell piece group 5, a second adhesive film 6 and a second cover plate 7. The cell piece group 5 comprises a plurality of photovoltaic cells, the plurality of photovoltaic cells are connected in series into cell strings through welding strips, and the plurality of cell strings are connected in series and / or parallel with each other through bus bars, so that the photovoltaic module comprises a plurality of photovoltaic cells, thereby improving the power generation efficiency of the photovoltaic module. The first adhesive film 4 and the second adhesive film 6 are respectively located on both sides of the cell piece group 5 in the thickness direction, the first cover plate 3 is located on the side of the first adhesive film 4 away from the cell piece group 5, and the second cover plate 7 is located on the side of the second adhesive film 6 away from the photovoltaic cell. The first adhesive film 4 and the second adhesive film 6 can be EVA adhesive film, POE adhesive film, composite adhesive film and the like, which can reduce the possibility of impurities such as water vapor and air contacting the photovoltaic cell, thereby improving the service life of the photovoltaic cell. When the photovoltaic module is impacted, the first adhesive film 4 and the second adhesive film 6 can also provide buffering for the photovoltaic cell, thereby reducing the possibility of stress-induced cracking of the photovoltaic cell. The first cover plate 3 can be photovoltaic glass, and the first cover plate 3 is located on the light-receiving surface of the photovoltaic cell. The photovoltaic glass has high light transmittance, which can improve the light absorption efficiency of the photovoltaic module, thereby improving the power generation efficiency of the photovoltaic module. The second cover plate 7 is located on the back surface of the photovoltaic cell, and the second cover plate 7 can be a back plate, thereby reducing the possibility of damage to the photovoltaic cell caused by the external environment. When the photovoltaic module is a double-glass module, the second cover plate 7 can also be photovoltaic glass, so that both sides of the photovoltaic cell can absorb sunlight, thereby improving the power generation efficiency of the photovoltaic module.

[0070] The photovoltaic cell is the photovoltaic cell described in any one of the preceding embodiments. Before the photovoltaic module is assembled, the photovoltaic cell is detected by Raman detection. When no characteristic peak is detected in the Raman spectrum of the photovoltaic cell, the grid line 2 has good metallic properties, and the photovoltaic cell has high power generation efficiency. After the photovoltaic module is used for a predetermined time, the state of the grid line 2 in the photovoltaic cell can be detected by Raman detection, and then it can be judged whether the photovoltaic cell can continue to work. The photovoltaic cell is detected by Raman detection without damaging the photovoltaic cell or the photovoltaic module, and the photovoltaic cell after detection can continue to be used, thereby reducing the detection cost.

[0071] The application relates to a photovoltaic cell and a photovoltaic assembly. The photovoltaic cell comprises a silicon substrate 1, a doped layer 11 is arranged on the surface of the silicon substrate 1, a PN junction is formed on the silicon substrate 1, and electric energy can be generated when sunlight irradiates the silicon substrate 1. A grid line 2 is arranged on the doped layer 11, the grid line 2 is electrically connected with the doped layer 11, and the grid line 2 can collect and export the electric energy generated in the doped layer 11. The grid line 2 is sintered from conductive paste, the conductive paste is metallized after being sintered into the grid line 2, and there is no characteristic peak in the Raman spectrum of the grid line 2. The state of the grid line 2 is analyzed through a spectrum formed by first laser Raman detection, and the possibility of damage to the grid line 2 in the detection process can be reduced. The state of the doped layer 11 can be analyzed through a Raman spectrum formed by second laser Raman detection. The Raman spectrum obtained by exciting the photovoltaic cell with the second laser after ultraviolet-induced attenuation can be used to analyze the attenuation degree of the doped layer 11, and the state of the doped layer 11 can also be detected in real time through the second laser.

Claims

1. A photovoltaic cell, characterized by, The photovoltaic cell comprises: a silicon substrate (1) provided with a doped layer (11) on the surface, and a grid line (2) provided on the doped layer (11) and electrically connected to the doped layer (11); wherein the grid line (2) is sintered from conductive paste, and after the conductive paste is sintered into the grid line (2), a first laser is radiated to the grid line (2), the radiation depth of the first laser on the photovoltaic cell is not greater than 2 um, the glass oxide in the grid line (2) is a dense network structure, and the grid line (2) exhibits no characteristic peaks in Raman spectrum.

2. The photovoltaic cell of claim 1, wherein, The Raman spectrum has a wave number range of 100 cm -1 to 3200 cm -1 .

3. The photovoltaic cell of claim 2, wherein, The silver particles in the gate line (2) have a dense crystal lattice structure, and the gate line (2) exhibits no characteristic peaks in the range of 200 cm -1 to 400 cm -1 in the Raman spectrum.

4. The photovoltaic cell of claim 2, wherein, There is no interface phonon coupling between the silver particles in the gate line (2) and the silicon substrate (1), and the gate line (2) exhibits no characteristic peak in the Raman spectrum in the range of 100 cm -1 to 200 cm -1 .

5. The photovoltaic cell of claim 2, wherein, After sintering, the additives in the gate line (2) are volatilized, and the gate line (2) exhibits no characteristic peaks in the Raman spectrum in the range of 600 cm -1 to 1800 cm -1 -1.

6. The photovoltaic cell of claim 2, wherein, After the preset time length or manual degradation treatment is used on the gate line (2), the silver particle lattice vibration amplitude is greater than the silver particle lattice vibration amplitude when the gate line (2) is in the initial state, and the gate line (2) has a characteristic peak in the range of 400 cm -1 to 1000 cm -1 in the Raman spectrum.

7. The photovoltaic cell of claim 2, wherein, The gate line (2) has carbon accumulation after being used for a preset length of time or after being manually degraded, and the gate line (2) exhibits a characteristic peak in a Raman spectrum in a range of 1100 cm -1 to 1700 cm -1 .

8. The photovoltaic cell of claim 2, wherein, After the gate line (2) is used for a time less than a preset time, silver oxide is present in the gate line (2), and the gate line (2) exhibits a characteristic peak in a Raman spectrum in a range of 150 cm -1 to 280 cm -1 .

9. The photovoltaic cell of claim 1, wherein, The wavelength range of the first laser is 400-2000 nm.

10. The photovoltaic cell of claim 1, wherein, The doped layer (11) has a silicon-boron bond, a second laser is radiated to the doped layer, and the radiation depth is less than 30 nm; before the photovoltaic cell is induced to attenuate by ultraviolet light, the silicon-boron bond is complete, the doped layer (11) has a first characteristic peak in Raman spectrum, and after the photovoltaic cell is induced to attenuate by ultraviolet light, the silicon-boron bond is broken, the doped layer (11) has a second characteristic peak in Raman spectrum; the wave number of the second characteristic peak is greater than that of the first characteristic peak, and the half-peak width of the second characteristic peak is less than that of the first characteristic peak.

11. A photovoltaic module, characterized by The photovoltaic module comprises a first cover plate (3), a first adhesive film (4), a cell piece group (5), a second adhesive film (6), and a second cover plate (7), the cell piece group (5) comprises a plurality of photovoltaic cells, and the photovoltaic cell is the photovoltaic cell according to any one of claims 1-10.

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