Method, system and device for characterizing edge loss after slicing of crystalline silicon solar cell

Abstract

The invention relates to the technical field of solar cell loss characterization, in particular to a characterization method, system and device for edge loss after slicing of a crystalline silicon solar cell, and the characterization method comprises the steps: cutting the crystalline silicon solar cell into a plurality of sub-cells with different areas along a crystal face, enabling the plurality of sub-cells to be in an open circuit state, exciting carriers in each sub-cell at different positions to obtain a plurality of small-disturbance transient photovoltages; based on the plurality of small-disturbance transient photovoltages, obtaining the carrier lifetime of the plurality of sub-cells; and according to the carrier lifetime of the plurality of sub-batteries, obtaining an evaluation result of the edge damage degree of the sub-batteries after slicing. According to the method, the nondestructive test is carried out by using small optical perturbation, and the influence of edge damage caused in the slicing process on the performance of the battery can be accurately captured by measuring small perturbation transient photovoltages at different positions, so that the edge loss degree is accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell loss characterization, and in particular to a method, system and device for characterizing edge loss of a crystalline silicon solar cell after slicing. Background Art

[0002] Photovoltaic technology is the most promising technology for obtaining clean and renewable energy. Crystalline silicon (c-Si) solar cells have maintained a dominant position in the industry with their mature process and significant market share (over 95%). In recent years, the iteration of photovoltaic technology has been changing with each passing day, gradually transitioning from traditional aluminum back surface field cells (Al-BSF) to efficient passivated emitter and back contact (PERC) technology. By the end of 2020, PERC technology has occupied more than 80% of the market share, and together with half-cell battery module technology, it has significantly reduced power consumption, increased system power output, and achieved large-scale commercial applications.

[0003] However, as the efficiency of PERC technology approaches the theoretical limit, the research focus in the photovoltaic field has shifted to the next generation of high-efficiency cell technologies, such as tunneling oxide passivation contact (TOPCon) and silicon heterojunction (SHJ) cells. These new passivation contact technologies have successfully pushed the photoelectric conversion efficiency to more than 26% by further reducing the recombination loss of crystalline silicon solar cells, opening a new era of photovoltaic efficiency.

[0004] In order to further improve the power density and efficiency of battery modules, the industry is actively exploring strategies to cut large-size solar panels into smaller sub-battery units. Through laser cutting technology, the entire cell is precisely divided into parts with an area of ​​1 / 2, 1 / 3, 1 / 4 or even smaller than the original cell, thereby achieving higher power output in a limited space and reducing energy losses between cells and modules. However, the unpassivated cutting edges produced in this process have become a key factor affecting the overall efficiency of the device because they cause additional compound losses.

[0005] Therefore, optimizing the cutting process to create a smoother cutting interface, implementing effective edge passivation measures, and developing accurate characterization methods to visualize edge loss have become the hot spots and difficulties in current photovoltaic technology research. Given that research in the field of edge loss characterization is still weak, the industry generally relies on photovoltaic electroluminescence (EL) technology to monitor the yield of the production line, but this is far from enough to fully reveal the edge loss mechanism of the device after slicing. Therefore, developing and applying advanced characterization techniques to intuitively display the edge loss status and deeply analyze the physical mechanism behind it is of great significance to promote the continuous advancement of photovoltaic cell technology and large-scale efficient production. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is: how to effectively reduce the composite loss of the unpassivated cut edges after slicing of crystalline silicon solar cells, and accurately quantify and visualize the edge loss to improve the overall efficiency of the cells.

[0007] In order to solve the above technical problems, the present invention provides a method for characterizing edge loss of a crystalline silicon solar cell after slicing, comprising the following steps:

[0008] S1: cutting a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, placing the plurality of sub-cells in an open circuit state, exciting carriers in each sub-cell at different positions, and obtaining a plurality of small-disturbance transient photovoltages;

[0009] S2: based on the multiple small perturbation transient photovoltages, obtaining the carrier lifetimes of the multiple sub-cells;

[0010] S3: obtaining an evaluation result of the damage degree of the edges of the sub-cells after slicing according to the carrier lifetimes of the plurality of sub-cells.

[0011] In one embodiment of the present invention, in S1, the method for obtaining multiple small-disturbance transient photovoltages is as follows:

[0012] For each sub-cell, a small optical perturbation is used to move from the edge of each sub-cell to the inside to obtain the small perturbation transient photovoltage at different distances from the edge cutting surface and the saturation voltage of the small perturbation transient photovoltage.

[0013] In one embodiment of the present invention, in S2, the method for obtaining the carrier lifetimes of the plurality of sub-batteries is:

[0014] S21: obtaining a transient photovoltage spectrum based on the multiple small-disturbance transient photovoltages;

[0015] S22: fitting the transient photovoltage spectrum according to the fitting expression of the carrier lifetime to obtain the carrier lifetimes of the plurality of sub-cells.

[0016] In one embodiment of the present invention, the fitting expression of the carrier lifetime τ is:

[0017]

[0018] Where ΔV(t) is the transient photo-generated voltage at the corresponding time point t during the test process, ΔV 0 is the saturation value of the transient photovoltage ΔV under small disturbance.

[0019] In one embodiment of the present invention, in S3, the method for obtaining the evaluation result of the edge damage degree of the sub-battery after slicing includes: obtaining the carrier recombination degree of different regions of the sub-battery after slicing based on the carrier lifetimes of the multiple sub-batteries, and obtaining the evaluation result of the edge damage degree of the sub-battery after slicing based on the carrier recombination degree.

[0020] In one embodiment of the present invention, in S1, the method of placing the plurality of sub-cells in an open circuit state is: irradiating the plurality of sub-cells with a white light source.

[0021] The present invention also provides a control system for implementing the steps of the above-mentioned method for characterizing the edge loss of a crystalline silicon solar cell after slicing, wherein the control system comprises the following modules:

[0022] A transient photovoltage acquisition module is used to cut a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, and to place the plurality of sub-cells in an open circuit state, to excite carriers in each sub-cell at different positions, and to obtain a plurality of small-disturbance transient photovoltages;

[0023] A carrier lifetime calculation module, used to obtain the carrier lifetimes of a plurality of sub-cells based on the plurality of small-disturbance transient photovoltages;

[0024] The damage degree assessment module is used to obtain an assessment result of the damage degree of the edge of the sub-battery after slicing according to the carrier lifetimes of the multiple sub-batteries.

[0025] The present invention also provides a device for characterizing the edge loss of a crystalline silicon solar cell after slicing, comprising the control system and the small-disturbance transient photovoltage testing device; wherein, the small-disturbance transient photovoltage testing device is used to obtain multiple small-disturbance transient photovoltages in different areas of the sub-cell after slicing when the circuit is open, and the control system performs fitting calculations based on the multiple small-disturbance transient photovoltages to obtain the carrier lifetime, and the degree of edge loss of the cell is evaluated based on the carrier lifetime.

[0026] In one embodiment of the present invention, the small disturbance transient photovoltage test device comprises a function signal generator, an oscilloscope, a pulse laser and a light source device;

[0027] The function signal generator is connected to the oscilloscope and the pulse laser respectively, the oscilloscope is connected to each sliced ​​sub-cell, and the light source device is used to irradiate each sliced ​​sub-cell to make it in an open circuit state. The pulse laser provides a small optical perturbation, and the small optical perturbation is used to move along the edge of the cut surface of the cell toward the inside thereof, and the oscilloscope obtains the small perturbation transient photovoltage at different positions.

[0028] In one embodiment of the present invention, the light source device provides a white light source.

[0029] The above technical solution of the present invention has the following advantages compared with the prior art:

[0030] 1. Accurately characterize edge loss: By measuring small perturbation transient photovoltage (TPV) at different locations, this technology can accurately capture the impact of edge damage caused by the slicing process on cell performance, and thus accurately evaluate the degree of edge loss.

[0031] 2. Non-destructive testing: This method uses small optical perturbations for non-destructive testing, which will not cause physical or chemical damage to the solar cells, ensuring that the tested cells can continue to be used or further analyzed.

[0032] 3. Multi-region analysis: By moving a small optical perturbation inward along the cut edge of the battery, TPV data at different positions can be obtained, thereby analyzing the carrier recombination degree and edge damage in different areas of the battery after slicing, providing a comprehensive damage assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0034] Figure 1 This is a flow chart of a method for characterizing edge loss after slicing a crystalline silicon solar cell provided in the first embodiment of the present invention;

[0035] Figure 2 is a flow chart of a method for obtaining carrier lifetimes of multiple sub-batteries provided in Embodiment 1 of the present invention;

[0036] Figure 3 It is a schematic diagram of the structure of a control system provided in the second embodiment of the present invention;

[0037] Figure 4 is a schematic structural diagram of a device for characterizing edge loss after slicing a crystalline silicon solar cell provided in the third embodiment of the present invention;

[0038] Figure 5 yes Figure 3 Schematic diagram of the structure of the small disturbance transient photovoltage test device;

[0039] Figure 6 (a) indicates the distance area is 1×1cm 2 Illustration of the small perturbation transient photovoltage (TPV) spectra and the carrier lifetime τ at different distances d from the edge of the SHJ cell under 520nm laser and white light. (b) shows the distance area of ​​1×1cm 2The carrier lifetime τ and photovoltage saturation value curve ΔV at different distances d from the edge of the SHJ cell under 520nm laser and white light 0 ;

[0040] Explanation of the figure marks in the specification: 100, transient photovoltage acquisition module; 200, carrier lifetime calculation module; 300, damage degree assessment module; 10, control system; 20, small disturbance transient photovoltage test device; 201, function signal generator; 202, oscilloscope; 203, pulse laser; 204, light source equipment. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0042] Embodiment 1

[0043] Reference Figure 1 As shown, the present invention provides a method for characterizing edge loss of a crystalline silicon solar cell after slicing, comprising the following steps:

[0044] S1: cutting a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, and irradiating the plurality of sub-cells with a white light source, so that the plurality of sub-cells are in an open circuit state, exciting carriers in each sub-cell at different positions, and obtaining a plurality of small-disturbance transient photovoltages;

[0045] S2: based on the multiple small perturbation transient photovoltages, obtaining the carrier lifetimes of the multiple sub-cells;

[0046] S3: obtaining an evaluation result of the damage degree of the edges of the sub-cells after slicing according to the carrier lifetimes of the plurality of sub-cells.

[0047] It can be seen from the above technical solution that the present invention can accurately capture the impact of edge damage that may be caused during the slicing process on the carrier lifetime by exciting the carriers in the subcell at different positions and measuring the small perturbation transient photovoltage. Carrier lifetime is one of the important indicators for evaluating the performance of solar cells, so this method can achieve high-precision evaluation of edge loss. In addition, the entire test process is carried out in an open circuit state, without the need for physical destruction or contact measurement of the solar cell, thereby avoiding additional damage that may be introduced during the test process and ensuring the accuracy and reliability of the test.

[0048] Furthermore, in S1, the method for obtaining multiple small-disturbance transient photovoltages is as follows:

[0049] For each sub-cell, a small optical perturbation is used as an excitation source. Through a precisely controlled optical pulse or light beam, starting from the edge cut surface of each sub-cell, it gradually moves into the cell along a preset path to obtain the small perturbation transient photovoltage at different distances from the edge cut surface and the saturation voltage of the small perturbation transient photovoltage. In this process, the small optical perturbation is used as an excitation source to effectively stimulate the dynamic response of the carriers inside the sub-cell, thereby generating an observable small perturbation transient photovoltage signal.

[0050] In order to fully capture this dynamic process, not only the instantaneous value of the small perturbation transient photovoltage was recorded at multiple different positions from the edge cutting surface, but also special attention was paid to the saturation state of the photovoltage signal at each position, that is, the saturation voltage of the small perturbation transient photovoltage. The acquisition of this parameter is crucial for a deep understanding of the recombination and transmission mechanism of carriers in different regions, and also provides key data support for the subsequent accurate calculation of the carrier lifetime.

[0051] like Figure 2 As shown, in S2, based on the multiple small perturbation transient photovoltages, the method for obtaining the carrier lifetimes of the multiple sub-batteries is:

[0052] S21: obtaining a transient photovoltage spectrum based on the multiple small-disturbance transient photovoltages;

[0053] S22: fitting the transient photovoltage spectrum according to the fitting expression of the carrier lifetime to obtain the carrier lifetimes of the plurality of sub-cells.

[0054]

[0055] Where ΔV(t) is the transient photo-generated voltage at the corresponding time point t during the test process, ΔV 0 is the saturation value of the transient photovoltage ΔV under small disturbance.

[0056] Further, in S3, the method for obtaining the evaluation result of the damage degree of the edge of the sub-cell after slicing according to the carrier lifetimes of the plurality of sub-cells is as follows:

[0057] In solar cells, carrier recombination is mainly divided into two types: direct recombination (such as radiation recombination) and indirect recombination (such as Shockley-Read-Hall recombination, Auger recombination, etc.). Edge damage often leads to an increase in defect states, which in turn promotes the occurrence of indirect recombination, thereby reducing carrier lifetime. Therefore, by comparing the differences in carrier lifetimes in different regions of the multiple sub-cells, the analysis results of the carrier recombination degree in the edge region and the internal region can be obtained;

[0058] Based on the analysis results of the carrier recombination degree in different regions, the evaluation results of the damage degree of the sub-cell edge after slicing are obtained. This evaluation result not only reflects the degree of performance degradation of the edge area relative to the internal area, but also provides an important reference for improving the production process of solar cells. For example, if the edge damage is found to be more serious, it may be necessary to adjust the slicing process parameters, optimize the edge passivation technology, or adopt more advanced packaging protection measures to reduce the damage.

[0059] Embodiment 2

[0060] The present invention also provides a control system for implementing the steps of the method for characterizing the edge loss of a crystalline silicon solar cell after slicing as described in the first embodiment. Figure 3 As shown, the control system includes the following modules:

[0061] The transient photovoltage acquisition module 100 is used to cut a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, and to place the plurality of sub-cells in an open circuit state, to excite carriers in each sub-cell at different positions, and to obtain a plurality of small-disturbance transient photovoltages;

[0062] A carrier lifetime calculation module 200, for obtaining carrier lifetimes of a plurality of sub-cells based on the plurality of small-disturbance transient photovoltages;

[0063] The damage degree assessment module 300 is used to obtain an assessment result of the damage degree of the edge of the sub-cell after slicing according to the carrier lifetimes of the plurality of sub-cells.

[0064] A control system proposed in this embodiment is used to implement the aforementioned method for characterizing edge loss after slicing a crystalline silicon solar cell. Therefore, the specific implementation method in the control system can be seen in the embodiment part of the aforementioned method for characterizing edge loss after slicing a crystalline silicon solar cell. For example, the transient photovoltage acquisition module 100, the carrier lifetime calculation module 200 and the damage degree assessment module 300 are respectively used to implement the steps S1, S2 and S3 of the method for characterizing edge loss after slicing a crystalline silicon solar cell in embodiment one. Therefore, its specific implementation method can refer to the description of the corresponding embodiments of each part. In order to avoid redundancy, it will not be repeated here.

[0065] Embodiment 3

[0066] like Figure 4As shown, the present invention also provides a device for characterizing the edge loss of a crystalline silicon solar cell after slicing, comprising the control system 10 and the small-disturbance transient photovoltage testing device 20 described in Example 2; wherein, the small-disturbance transient photovoltage testing device 20 is used to obtain multiple small-disturbance transient photovoltages in different areas of the sub-cell after slicing when the circuit is open, and the control system 10 performs fitting calculations based on the multiple small-disturbance transient photovoltages to obtain the carrier lifetime, and evaluates the degree of edge loss of the cell according to the carrier lifetime.

[0067] Furthermore, if Figure 5 As shown, the small disturbance transient photovoltage test device 20 includes a function signal generator 201, an oscilloscope 202, a pulse laser 203 and a light source device 204;

[0068] The function signal generator 201 is connected to the oscilloscope 202 to send a trigger signal to the oscilloscope 202 to ensure that the oscilloscope 202 captures and records the small disturbance transient photovoltage signal from the sub-cell at the correct time point. This trigger and synchronization mechanism helps to ensure the accuracy and consistency of the data. The function signal generator 201 can also generate a signal for controlling the operation of the oscilloscope 202, such as setting the sampling rate, trigger level and other parameters of the oscilloscope 202 to optimize the capture and processing of the transient photovoltage signal.

[0069] In addition, the function signal generator 201 is connected to the pulse laser 203. The control signal generated by the function signal generator 201 is used to control the operation of the pulse laser 203, including the generation of pulses, frequency, pulse width and other parameters. This ensures that the pulse laser 203 can output small optical perturbations according to the predetermined timing and characteristics to excite the carriers in the subcell and generate transient photovoltage signals. It is particularly critical that, through the precise control of the function signal generator 201, each pulse output by the pulse laser 201 can be seamlessly synchronized with the sampling operation of the oscilloscope 202. This synchronization is indispensable for capturing and analyzing transient photovoltage signals with extremely short time scales and high sensitivity. It greatly improves the accuracy and reliability of the test, making it possible to more accurately evaluate the edge loss of crystalline silicon solar cells after slicing.

[0070] The oscilloscope 202 is connected to each sliced ​​sub-cell, and the light source device 204 provides a white light source to illuminate all the sliced ​​sub-cells, making them in an open circuit state. The pulse laser 203 provides a small optical perturbation, and the small optical perturbation is used to move along the edge of the cut surface of the cell toward the inside, and the oscilloscope 202 obtains the small perturbation transient photovoltage at different positions.

[0071] The following experiments further verify the performance of the method, system and device for characterizing the edge loss of crystalline silicon solar cells after slicing proposed by the present invention. The finished SHJ solar cell is sliced ​​along the crystal plane into 1×1 cm 2 sub-battery.

[0072] Area size: 1×1cm 2 The TPV curves of the SHJ sub-cell at different positions from the edge are tested by TPV. The device is in an open circuit state under white light irradiation, and then under the perturbation provided by a small pulse laser, the oscilloscope 202 displays the TPV curve of the device under small optical perturbation, and the carrier lifetime τ is obtained through fitting, which can be used to monitor the degree of carrier recombination in the solar cell.

[0073] like Figure 6 (a) shows the saturation value of the photovoltage at the edge (d≈61 μm) of the SHJ. 0 According to formula (1), it can be calculated that τ at different distances from the edge cutting surface is 240.5μs (d≈61μm), 248.1μs (d≈122μm) and 286.3μs (d≈366μm). In addition, Figure 6 As shown in (b), τ increases with the distance from the edge cutting surface. The above results indicate that the carriers lost by SHJ cutting undergo serious recombination at the edge.

[0074] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0075] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0076] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0077] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0078] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for characterizing edge loss of crystalline silicon solar cells after slicing, characterized in that: The following steps are involved: S1: cutting a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, placing the plurality of sub-cells in an open circuit state, exciting carriers in each sub-cell at different positions, and obtaining a plurality of small-disturbance transient photovoltages; S2: based on the multiple small perturbation transient photovoltages, obtaining the carrier lifetimes of the multiple sub-cells; S3: obtaining an evaluation result of the damage degree of the edges of the sub-cells after slicing according to the carrier lifetimes of the plurality of sub-cells.

2. The method for characterizing the edge loss of a crystalline silicon solar cell after slicing according to claim 1, characterized in that: In S1, the method for obtaining multiple small perturbation transient photovoltages is as follows: For each sub-cell, a small optical perturbation is used to move from the edge of each sub-cell to the inside to obtain the small perturbation transient photovoltage at different distances from the edge cutting surface and the saturation voltage of the small perturbation transient photovoltage.

3. The method for characterizing edge loss after slicing of a crystalline silicon solar cell according to claim 1, characterized in that: In S2, the method for obtaining the carrier lifetimes of multiple sub-batteries is: S21: obtaining a transient photovoltage spectrum based on the multiple small-disturbance transient photovoltages; S22: fitting the transient photovoltage spectrum according to the fitting expression of the carrier lifetime to obtain the carrier lifetimes of the plurality of sub-cells.

4. The method for characterizing edge loss after slicing a crystalline silicon solar cell according to claim 3, characterized in that: The fitting expression of the carrier lifetime τ is: Wherein, ΔV(t) is the transient photovoltage at the corresponding time point t during the test process, and ΔV0 is the saturation value of the small-disturbance transient photovoltage ΔV.

5. The method for characterizing edge loss after slicing of a crystalline silicon solar cell according to claim 1, characterized in that: In S3, the method for obtaining the evaluation result of the damage degree of the edge of the sub-battery after slicing includes: obtaining the carrier recombination degree of different regions of the sub-battery after slicing according to the carrier lifetimes of the multiple sub-batteries, and obtaining the evaluation result of the damage degree of the edge of the sub-battery after slicing according to the carrier recombination degree.

6. The method for characterizing edge loss after slicing of a crystalline silicon solar cell according to claim 1, characterized in that: In S1, the method of placing the plurality of sub-cells in an open circuit state is: irradiating the plurality of sub-cells with a white light source.

7. A control system, characterized in that: The control system is used to implement the method for characterizing the edge loss after slicing a crystalline silicon solar cell according to any one of claims 1 to 6, wherein the control system comprises the following modules: A transient photovoltage acquisition module is used to cut a crystalline silicon solar cell into a plurality of sub-cells of different sizes along a crystal plane, and to place the plurality of sub-cells in an open circuit state, to excite carriers in each sub-cell at different positions, and to obtain a plurality of small-disturbance transient photovoltages; A carrier lifetime calculation module, used to obtain the carrier lifetimes of a plurality of sub-cells based on the plurality of small-disturbance transient photovoltages; The damage degree assessment module is used to obtain an assessment result of the damage degree of the edge of the sub-battery after slicing according to the carrier lifetimes of the multiple sub-batteries.

8. A device for characterizing edge loss of crystalline silicon solar cells after slicing, characterized in that: It comprises the control system and the small disturbance transient photovoltage test device as claimed in claim 7; Among them, the small perturbation transient photovoltage testing device is used to obtain multiple small perturbation transient photovoltages in different areas of the sliced ​​sub-cell when the circuit is open. The control system performs fitting calculations based on the multiple small perturbation transient photovoltages to obtain the carrier lifetime, and the battery edge loss degree is evaluated based on the carrier lifetime.

9. The device for characterizing the edge loss after slicing a crystalline silicon solar cell according to claim 8, characterized in that: The small disturbance transient photovoltage test device comprises a function signal generator, an oscilloscope, a pulse laser and a light source device; The function signal generator is connected to the oscilloscope and the pulse laser respectively, the oscilloscope is connected to each sliced ​​sub-cell, and the light source device is used to irradiate each sliced ​​sub-cell to make it in an open circuit state. The pulse laser provides a small optical perturbation, and the small optical perturbation is used to move along the edge of the cut surface of the cell toward the inside thereof, and the oscilloscope obtains the small perturbation transient photovoltage at different positions.

10. The device for characterizing edge loss after slicing of a crystalline silicon solar cell according to claim 9, characterized in that: The light source device provides a white light source.

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