Device and method for testing electroluminescence of sub-cell of laminated solar cell

Abstract

The invention provides a device and a method for testing electroluminescence of a sub-cell of a laminated solar cell, and belongs to the technical field of photovoltaic cell testing, the device comprises a current injection module, at least two Si-CCD cameras, at least two optical filters, a light source compensation device, a data acquisition module, an output module and an objective table, the two Si-CCD cameras are adopted, and the data acquisition module is used for acquiring the electroluminescence of the sub-cell of the laminated solar cell. And light-emitting images of the perovskite and the silicon sub-cell are respectively captured, so that rapid and accurate detection is realized. The cell is excited to emit light through current injection, an image processing system recognizes defects such as local short circuit, material unevenness and microcracks, the resistance coupling effect of the perovskite and the silicon sub-cell is analyzed, and long-term stability analysis of the cell is carried out. Due to the introduction of the multispectral imaging technology, the limitation of the existing detection technology is solved, and the detection efficiency and accuracy in the production process of the perovskite-silicon laminated cell are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cell testing, and in particular to a device and method for sub-cell resolution electroluminescence imaging of a perovskite / crystalline silicon stacked solar cell. Background Art

[0002] As global energy demand grows, photovoltaic technology has become an important way to provide sustainable energy. The efficiency of traditional silicon-based solar cells is limited to 29.43%. To break through this bottleneck, perovskite / crystalline silicon stacked solar cells have emerged, with the highest efficiency reaching 34.6%. However, its commercialization faces challenges such as material toxicity, equipment stability and large-scale production. In particular, accurate and rapid characterization of battery performance and online detection in large-scale production are still issues that need to be solved.

[0003] As a non-destructive detection method, electroluminescence (EL) technology has been widely used in the quality inspection of solar cells because of its advantages such as fast speed, high spatial resolution and simple operation, such as the method used in the literature ACS Appl. Mater. Interfaces 2024, 16, 32, 41986–41995 and patent CN118131384A. EL imaging can reveal the lateral distribution of electrical performance in the battery by detecting the light emission intensity of the battery when it is powered on, and quickly discover defects inside the battery, such as microcracks, short circuits, and passivation layer problems. This technology can not only monitor the health status of the battery in real time, but also provide data support for subsequent process optimization. Especially in multi-junction batteries, EL imaging can characterize the performance of each sub-battery separately, thereby greatly improving the accuracy and efficiency of detection. Therefore, in the large-scale production of perovskite / crystalline silicon stacked cells, the application of EL imaging technology is particularly important, which helps to ensure product quality and improve production efficiency. To date, there have been many studies on the electroluminescence (EL) properties of multi-junction cells, especially the recent studies on two-terminal (2T) perovskite / crystalline silicon tandem solar cells. These studies have mainly focused on improving the understanding and performance of multi-junction solar cells through EL imaging techniques. For example, the combination of EL, photoluminescence (PL) and lock-in thermography measurements can identify the local characteristics of the cell. The external quantum efficiency of EL can provide information about the IV relationship, internal voltage, sheet resistance and shunt resistance of individual sub-cells. Although the equipment configuration in these studies is very suitable for use in academic research, it is still a technical challenge to simultaneously record sub-cell images and control the integration time in the millisecond range in an industrial online test environment. In addition, during the signal capture of the tandem cell, the electroluminescence of the bottom cell will be absorbed or scattered by the upper cell, which will reduce the accuracy of the imaging system, thus affecting the overall imaging effect. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a sub-cell electroluminescence testing device and method for stacked solar cells, which is mainly used for online detection and quality control in photovoltaic cell production. The device design of the present invention aims to solve the problem that the defects of each sub-cell of the perovskite-silicon multi-junction cell cannot be quickly and accurately detected in the prior art. Through innovative multi-spectral imaging technology, electroluminescence imaging of perovskite and silicon sub-cells can be performed separately, thereby providing accurate defect detection and performance evaluation.

[0005] The first aspect of the present application provides a sub-cell electroluminescence imaging test device for perovskite-silicon tandem solar cells. It includes: a current injection module, used to inject current into the cell to be tested to generate electroluminescence; at least two Si-CCD cameras, capturing the image information of the cell luminescence; at least two filters, filtering the light of different wavelengths emitted by the cell; a light source compensation device, emitting light of a specific wavelength and injecting it into the cell; a data acquisition module, responsible for receiving the image data collected by the Si-CCD camera and transmitting it to the output module; an output module, receiving the image data of the data acquisition module and processing and analyzing it; a stage, used to carry the cell to be tested.

[0006] Furthermore, the cell to be tested is a perovskite-silicon tandem solar cell.

[0007] In some embodiments, the current injection device is used to inject current into the perovskite-silicon tandem solar cell to stimulate the electroluminescence phenomenon in the cell. By adjusting the current density, the working state of the cell can be controlled, and electroluminescence images under different current conditions can be obtained respectively. Subsequently, a camera is used to record the image of the cell when it is luminous, so as to identify defects in the cell, such as material inhomogeneity, local short circuit, and current leakage.

[0008] Furthermore, the test device described in the present application can detect the defect changes of the battery under different operating conditions by adjusting the current density, and obtain electroluminescent images under different current conditions. This method can detect subtle defects that are difficult to find under traditional detection methods, and provide accurate data support for the process improvement of perovskite-silicon batteries.

[0009] In some embodiments, the test device also includes a current density controllable power supply device, connected to the battery to be tested, for applying a forward bias, and capable of maintaining the voltage for a long time under different current injection densities, so as to observe the changes in the luminous intensity of the perovskite and silicon sub-cells under bias conditions. Through the dynamic adjustment of the current density range, the performance changes of the battery under different working conditions can be evaluated.

[0010] Furthermore, the test device can monitor the degradation of the battery by applying a forward bias voltage for a long time. Studies have found that the degradation of the battery under bias conditions usually starts from the edge of the battery and gradually expands to the center. The device can effectively identify the degradation location and severity of the battery by continuously monitoring the changes in the electroluminescent image.

[0011] Furthermore, at least two of the Si-CCD cameras are used to capture the luminescent images after being filtered by at least two filters. At least one filter is a short-wave pass filter, which is dedicated to capturing the luminescence of the perovskite cell; at least one filter is a long-wave pass filter, which is used to capture the luminescence of the silicon cell. At least two Si-CCD cameras record their own image information respectively, ensuring that the two luminescent images are synchronously acquired within milliseconds.

[0012] The filter is used to filter light of different wavelengths to distinguish the luminescence of perovskite and silicon cells. The short-wave filter can block the long-wave infrared light of the silicon cell and only allow the short-wave luminescence of the perovskite sub-cell to pass; the long-wave filter is used to block the luminescence of the perovskite layer and only capture the infrared luminescence of the silicon cell.

[0013] The light source compensation device is responsible for detecting the energy lost when the electroluminescent signal of the bottom battery is absorbed or scattered by the middle layer when passing through the upper battery, and bleaching the signal attenuation caused by the shading of the upper battery by emitting light of a specific wavelength, thereby enhancing the imaging effect of the bottom battery.

[0014] The data acquisition module is responsible for receiving the image data collected by the Si-CCD camera and transmitting it to the output module for further processing and analysis. The data acquisition module uses image processing algorithms to remove noise and adjust image contrast to make defect identification more accurate.

[0015] The output module is used to generate analysis results, including identification of local short circuits, material inhomogeneities, microcracks and other defects in the cell. The analyzed image data can also be used to generate defect detection reports and record the luminescence characteristics and performance differences of the perovskite and silicon subcells.

[0016] Another aspect of the present invention provides a method for testing the electroluminescence of a sub-cell of a stacked solar cell, which is performed using the above-mentioned testing device and comprises the following steps:

[0017] S1: Use a current injection module to apply a preset current density to the perovskite-silicon tandem solar cell to be tested to stimulate electroluminescence;

[0018] S2: two Si-CCD cameras cooperate with the filters to capture the electroluminescence image of the perovskite-silicon tandem solar cell to be tested;

[0019] S3: The light source compensation device detects the light signal loss of the silicon subcell and offsets the absorption effect by emitting a compensation light signal, thereby improving the accuracy of the imaging system and ensuring the clarity and accuracy of electroluminescent imaging;

[0020] S4: The data acquisition module compares and analyzes the luminescent images of the perovskite subcell and the silicon subcell;

[0021] S5: The image processing result of the data acquisition module generates a test report through the output module, and the report includes the battery defect location, defect type and its severity.

[0022] Specifically, at least one Si-CCD camera captures the luminescence of the perovskite sub-cell through a short-wave filter, and at least one Si-CCD camera captures the luminescence of the silicon sub-cell through a long-wave filter. Through the spectroscopic technology of the filter, it is ensured that each camera only captures the luminescence image of the corresponding sub-cell, thereby achieving independent imaging of the sub-cell.

[0023] The embodiment of the present invention provides a sub-cell electroluminescence testing device and method for perovskite-silicon tandem solar cells. The device uses two Si-CCD cameras to capture the luminescent images of the perovskite and silicon sub-cells respectively, so as to achieve fast and accurate detection. The cell is stimulated to emit light through current injection, and the image processing system identifies defects such as local short circuits, material unevenness and microcracks, and analyzes the resistance coupling effect of the perovskite and silicon sub-cells to perform long-term stability analysis of the cell. The introduction of this multi-spectral imaging technology solves the limitations of existing detection technologies and greatly improves the detection efficiency and accuracy in the production process of perovskite-silicon tandem cells. The device improves the online detection efficiency in large-scale production and provides technical support for battery quality control and process optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a sub-cell electroluminescence testing device of a stacked solar cell provided by an embodiment of the present invention.

[0026] Figure 2 It is a step diagram of a control method of a sub-cell electroluminescence testing device of a stacked solar cell provided by an embodiment of the present invention.

[0027] Figure 3This is an EL image of a perovskite subcell in a perovskite / crystalline silicon tandem solar cell provided in an embodiment of the present invention.

[0028] Figure 4 This is an EL image of a silicon subcell in a perovskite / crystalline silicon tandem solar cell provided by an embodiment of the present invention.

[0029] The reference numerals are as follows:

[0030] 110, current injection module; 210 / 220, Si-CCD camera; 230 / 240, filter; 310, light source compensation device; 410, data acquisition module; 420, output module; 510, stage. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "inside", "outside", "front end", "rear end", "head", "tail", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0033] See also Figure 1 The embodiment of the present invention provides a sub-cell electroluminescence test device for a stacked solar cell, comprising: a current injection module 110, used to inject current into a cell to be tested to generate electroluminescence; at least two Si-CCD cameras 210, 220, used to capture image information of cell luminescence; at least two filters 230, 240, used to filter light of different wavelengths emitted by the cell; a light source compensation device 310, used to emit light of a specific wavelength and inject it into the cell; a data acquisition module 410, responsible for receiving image data acquired by the Si-CCD cameras 210, 220 and transmitting it to an output module 420; the output module 420, used to receive the image data of the data acquisition module 410 and process and analyze it; and a stage 510, used to carry the cell to be tested.

[0034] in:

[0035] The stage 510 is a flat platform for placing the perovskite-silicon stacked solar cell to be tested. The cell is fixed on the stage during the test to ensure the stability of the cell during current injection. The current injection module 110 applies a preset current to the cell to stimulate electroluminescence.

[0036] In some embodiments, the test device also includes a current density controllable power supply device, connected to the battery to be tested, for applying a forward bias, and capable of maintaining the voltage for a long time under different current injection densities, so as to observe the changes in the luminous intensity of the perovskite and silicon sub-cells under bias conditions. Through the dynamic adjustment of the current density range, the performance changes of the battery under different working conditions can be evaluated.

[0037] Furthermore, the test device can monitor the degradation of the battery by applying a forward bias voltage for a long time. Studies have found that the degradation of the battery under bias conditions usually starts from the edge of the battery and gradually expands to the center. The device can effectively identify the degradation location and severity of the battery by continuously monitoring the changes in the electroluminescent image.

[0038] The Si-CCD cameras 210 and 220 are used to capture the luminescent images after being filtered by the filters 230 and 240, respectively. The filter 230 equipped with the Si-CCD camera 210 is a short-wave pass filter, which is specially used to capture the luminescence of the perovskite cell; the filter 240 equipped with the Si-CCD camera 220 is a long-wave pass filter, which is used to capture the luminescence of the silicon cell. The two cameras record their own luminescent information respectively, ensuring that the two luminescent images are synchronously acquired within milliseconds.

[0039] The filters 230 and 240 are used to filter light of different wavelengths to distinguish the light emitted by the perovskite and silicon cells. The filter 230 can block the long-wave infrared light of the silicon cell and only allow the short-wave light emitted by the perovskite subcell to pass through; the filter 240 is used to block the light emitted by the perovskite layer and only capture the infrared light emitted by the silicon cell.

[0040] The light source compensation device 310 is responsible for detecting the energy lost when the electroluminescent signal of the bottom cell is absorbed or scattered by the upper cell, and by emitting light of a specific wavelength to compensate for the signal attenuation caused by the shading of the upper cell, thereby enhancing the imaging effect of the bottom cell.

[0041] The data acquisition module 410 is responsible for receiving the image data collected by the Si-CCD cameras 210 and 220 and transmitting it to the output module 420 for further processing and analysis. The data acquisition module removes noise and adjusts image contrast through image processing algorithms to make defect identification more accurate.

[0042] The output module 420 is used to generate analysis results, including identifying defects such as local short circuits, material inhomogeneities, microcracks, etc. in the battery. The analyzed image data can also be used to generate defect detection reports and record the luminescence characteristics and performance differences of the perovskite and silicon subcells.

[0043] See also Figure 2 The present invention provides a method for testing the electroluminescence of a sub-cell of a stacked solar cell, which is performed using the above-mentioned device and includes the following steps:

[0044] S1: Use the current injection module 110 to apply a preset current density to the perovskite-silicon tandem solar cell to be tested to stimulate electroluminescence.

[0045] Specifically, the current injection module 110 can adjust the magnitude of the current to simulate different working conditions, thereby ensuring that the light-emitting characteristics of the battery under different current conditions are tested.

[0046] S2: The two Si-CCD cameras 210 and 220 cooperate with the filters 230 and 240 to capture the electroluminescent image of the perovskite-silicon tandem solar cell to be tested.

[0047] Specifically, the Si-CCD camera 210 captures the luminescence of the perovskite subcell through the short-wave filter 230, while the Si-CCD camera 220 captures the luminescence of the silicon subcell through the long-wave filter 240. Through the spectroscopic technology of the filter, it is ensured that each camera only captures the luminescence image of the corresponding subcell, thereby realizing independent imaging of the subcell.

[0048] S3: The light source compensation device 310 detects the light signal loss of the silicon subcell and offsets the absorption effect by emitting a compensation light signal, thereby improving the accuracy of the imaging system and ensuring the clarity and accuracy of the electroluminescent imaging.

[0049] S4: The data acquisition module 410 compares and analyzes the luminescent images of the perovskite sub-cell and the silicon sub-cell.

[0050] Specifically, this analysis can identify common defects in the cell, such as local short circuits, material inhomogeneities, and microcracks. By comparing the difference in luminescence intensity between the two, the resistive coupling effect between the subcells can be further analyzed to detect defects across the subcells.

[0051] S5: The image processing results of the data acquisition module 410 are used to generate a test report through the output module 420, which includes the battery defect location, defect type and severity. The report can be used to evaluate battery performance and provide a reference for process adjustments in subsequent production processes.

[0052] Embodiment 1:

[0053] This embodiment is a test procedure and test results of electroluminescence imaging of a perovskite / crystalline silicon tandem solar cell, which is performed using the imaging device and test method described in the present invention. Specifically, the following steps are included:

[0054] S1: Adjust the DC voltage of a voltage regulator to 2.5V and apply 10 mA / cm to the perovskite-silicon tandem solar cell to be tested. 2 The injected current density.

[0055] S2: Near-infrared parasitic absorption losses in the bleached tandem cell compensated by a 365 nm monochromatic light-emitting diode.

[0056] S3: The luminescence image of the perovskite subcell in the stacked cell is collected by a narrow-band 808 nm CCD camera with a 700 nm long-pass filter;

[0057] S4: The narrow-band 1050 nm CCD camera and 850 nm long-pass filter capture the luminescence image of the silicon subcell in the stacked cell. Figure 3 and Figure 4 The EL images of the obtained perovskite sub-cell and silicon sub-cell are respectively.

[0058] The present invention provides a sub-cell electroluminescence (EL) imaging test device and test method of a perovskite-silicon tandem solar cell, aiming to solve the problem that multi-junction cells cannot be efficiently and accurately detected in the prior art. By using two Si-CCD cameras and filters with different wavelengths, independent imaging of perovskite sub-cells and silicon sub-cells is achieved, ensuring that the luminescence characteristics of each sub-cell can be captured and analyzed separately, and adding a light source compensation device to ensure that the electroluminescence images of the two layers of cells can accurately reflect their defect distribution, thereby improving the accuracy and reliability of the test.

[0059] The key technical points of the present invention are its filter spectroscopic technology, light source compensation device, dual-camera synchronous imaging system and efficient image processing algorithm, which can accurately detect defects such as local short circuits, material inhomogeneity and microcracks. At the same time, by comparing and analyzing the luminescent images of perovskite and silicon sub-cells, the resistance coupling effect between the sub-cells is detected, which improves the overall detection efficiency and accuracy. The present invention can be applied to online quality control in large-scale production, effectively improving the production yield and reliability of perovskite-silicon cells.

Claims

1. A sub-cell electroluminescence testing device for a stacked solar cell, characterized in that: include: A current injection module, used for injecting current into the battery to be tested to generate electroluminescence; At least two Si-CCD cameras to capture image information of the battery’s luminescence; At least two filters to filter different wavelengths of light emitted by the battery; A light source compensation device emits light of a specific wavelength and injects it into the battery; A data acquisition module is responsible for receiving the image data collected by the Si-CCD camera and transmitting it to the output module; An output module receives image data from the data acquisition module and processes and analyzes it; The stage is used to carry the battery to be tested.

2. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The cell to be tested is a perovskite-silicon tandem solar cell.

3. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The testing device detects defect changes of the battery under different operating conditions by adjusting the current density, and obtains electroluminescent images under different current conditions.

4. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The test device also includes a current density controllable power supply device, which is connected to the battery to be tested and is used to apply a forward bias voltage and can maintain the voltage for a long time under different current injection densities.

5. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 4, characterized in that: The test device monitors the degradation of the battery by applying a forward bias voltage for a long time.

6. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: At least two of the Si-CCD cameras are used to capture luminescent images after being filtered by at least two filters; at least one filter is a short-wave pass filter, which is dedicated to capturing the luminescence of perovskite cells; and at least one filter is a long-wave pass filter, which is used to capture the luminescence of silicon cells.

7. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The light source compensation device detects the energy lost when the electroluminescent signal of the bottom cell is absorbed or scattered by the middle layer when passing through the upper cell, and bleaches the signal attenuation caused by the shading of the upper cell by emitting light of a specific wavelength, thereby enhancing the imaging effect of the bottom cell.

8. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The data acquisition module removes noise and adjusts image contrast through image processing algorithms to make defect identification more accurate.

9. The sub-cell electroluminescence testing device of the tandem solar cell according to claim 1, characterized in that: The output module is used to generate analysis results, including identifying local short circuits, material inhomogeneities, and microcrack defects in the battery.

10. A method for testing electroluminescence of a sub-cell of a tandem solar cell, applied to the electroluminescence testing device for a sub-cell of a tandem solar cell as claimed in any one of claims 1 to 9, characterized in that: Includes steps: S1: Use a current injection module to apply a preset current density to the perovskite-silicon tandem solar cell to be tested to stimulate electroluminescence; S2: two Si-CCD cameras are used to capture the electroluminescence image of the perovskite-silicon tandem solar cell to be tested respectively in cooperation with the filter; S3: The light source compensation device detects the light signal loss of the silicon subcell and offsets the absorption effect by emitting a compensation light signal, thereby improving the accuracy of the imaging system and ensuring the clarity and accuracy of electroluminescent imaging; S4: The data acquisition module compares and analyzes the luminescent images of the perovskite sub-cell and the silicon sub-cell; S5: The image processing result of the data acquisition module generates a test report through the output module, and the report includes the battery defect location, defect type and its severity.

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