Sub-cell electroluminescence test device and method for a stacked solar cell

Abstract

The present invention provides a sub-cell electroluminescence test device and method for a stacked solar cell, belonging to the technical field of photovoltaic cell testing. The device includes a current injection module, at least two Si-CCD cameras, at least two filters, a light source compensation device, a data acquisition module, an output module, and a stage. By using two Si-CCD cameras to respectively capture the luminescence images of the perovskite and silicon sub-cells, rapid and accurate detection can be achieved. The battery is excited to emit light through current injection, and the image processing system identifies defects such as local short circuits, material inhomogeneity, and microcracks, and analyzes the resistance coupling effect of the perovskite and silicon sub-cells to conduct long-term stability analysis of the battery. 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 stacked cells.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cell testing, and particularly relates to an apparatus and method for sub-cell resolution electroluminescence imaging of perovskite / silicon heterojunction solar cells. Background Art

[0002] With the growth of global energy demand, photovoltaic technology has become an important way to provide sustainable energy. The efficiency of traditional silicon-based solar cells is limited, with a maximum of 29.43%. To break through this bottleneck, perovskite / silicon heterojunction solar cells have emerged, with a maximum efficiency of 34.6%. However, their commercialization faces challenges such as material toxicity, device stability, and large-scale production. In particular, accurate and rapid battery performance characterization and on-line detection in large-scale production are still urgent problems to be solved.

[0003] Electroluminescence (EL) technology, as a non-destructive testing method, has been widely used in the quality inspection of solar cells due to its advantages of fast speed, high spatial resolution, and simple operation, such as the methods used in the literature ACS Appl. Mater. Interfaces 2024, 16, 32, 41986–41995 and the patent CN118131384A. EL imaging can reveal the lateral distribution of electrical performance in the battery by detecting the light emission intensity of the battery under the energized state, and quickly discover internal defects in 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 cells, EL imaging can separately characterize the performance of each sub-cell, thus greatly improving the accuracy and efficiency of detection. Therefore, in the large-scale production of perovskite / silicon heterojunction cells, the application of EL imaging technology is particularly important, which helps to ensure product quality and improve production efficiency. So far, many studies have been carried out on the electroluminescence (EL) characteristics of multi-junction cells, especially recent studies on two-terminal (2T) perovskite / silicon heterojunction solar cells. These studies mainly focus on improving the understanding and performance of multi-junction solar cells through EL imaging technology. For example, the combination of EL, photoluminescence (PL), and lock-in thermography measurements can identify the local characteristics of the battery, and the external quantum efficiency of EL can provide information such as the I-V relationship, internal voltage, sheet resistance, and shunt resistance of a single sub-cell. Although the equipment configurations in these studies are very suitable for use in academic research, in an industrial on-line testing environment, it is still a technical challenge to simultaneously record sub-cell images and control the integration time within the millisecond range. In addition, during the process of signal capture for the heterojunction cell, since the electroluminescence part of the bottom cell will be absorbed or scattered by the upper cell, it will reduce the accuracy of the imaging system, thus affecting the overall imaging effect. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a sub-cell electroluminescence test device and method for a tandem solar cell, which are mainly used for on-line detection and quality control in photovoltaic cell production. The device design of the present invention aims to solve the problem in the prior art that it is impossible to quickly and accurately detect the defects of each sub-cell of a perovskite-silicon multi-junction cell. Through innovative multi-spectral imaging technology, electroluminescence imaging can be performed on perovskite and silicon sub-cells respectively, thereby providing precise defect detection and performance evaluation.

[0005] The first aspect of the present application provides a sub-cell electroluminescence imaging test device for a perovskite-silicon tandem solar cell. It includes: a current injection module for injecting current into the battery to be tested to generate electroluminescence; at least two Si-CCD cameras for capturing image information of the battery's light emission; at least two filter films for filtering light of different wavelengths emitted by the battery; a light source compensation device for emitting light of a specific wavelength and injecting it onto the battery; a data acquisition module responsible for receiving the image data collected by the Si-CCD cameras and transmitting it to the output module; an output module for receiving the image data of the data acquisition module and performing processing and analysis; and a stage for carrying the battery to be tested.

[0006] Further, the battery 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, the camera is used to record the image of the cell when it emits light, so as to identify defects in the cell, such as material non-uniformity, local short circuit, and current leakage, etc.

[0008] Further, the test device of the present application can detect the defect changes of the cell under different operating conditions by adjusting the current density, and obtain electroluminescence images under different current conditions respectively. This method can detect subtle defects that are difficult to discover by traditional detection means, and provide accurate data support for the process improvement of perovskite-silicon cells.

[0009] In some embodiments, the test device further includes a power supply device with controllable current density, which is connected to the battery to be tested, used to apply a forward bias voltage, and can maintain the voltage for a long time under different current injection densities, so as to observe the change of the light emission intensity of perovskite and silicon sub-cells under the bias voltage condition. By dynamically adjusting the current density range, the performance change of the cell under different working conditions can be evaluated.

[0010] Furthermore, the testing device can monitor the degradation of the battery by applying a forward bias for a long time. It has been found that the degradation of the battery under bias conditions usually starts from the edge of the battery and gradually spreads towards the center. By continuously monitoring the changes in the electroluminescence images, this device can effectively identify the degradation location and severity of the battery.

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

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

[0013] The light source compensation device is responsible for detecting the energy lost when the electroluminescence signal of the bottom battery is absorbed or scattered by the intermediate layer when passing through the upper battery, and by emitting light of a specific wavelength, bleaching the signal attenuation caused by the upper battery occlusion and 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 cameras 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 the image contrast to make defect identification more accurate.

[0015] The output module is used to generate analysis results, including identifying defects such as local short circuits, material inhomogeneities, and microcracks in the battery. The analyzed image data can also be used to generate a defect detection report and record the luminescence characteristics and performance differences of the perovskite and silicon sub-batteries.

[0016] On the other hand, the present invention also provides a method for testing the electroluminescence of a sub-battery of a tandem solar cell, which is carried out using the above-mentioned testing device and includes the steps:

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

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

[0019] S3: The light source compensation device detects the loss of the luminescence signal of the silicon sub-cell, and cancels the absorption effect by emitting a compensation optical signal, thereby improving the accuracy of the imaging system and ensuring the clarity and accuracy of the electroluminescence imaging;

[0020] S4: The data acquisition module compares and analyzes the luminescence images of the perovskite sub-cell and the silicon sub-cell;

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

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

[0023] The embodiment of the present invention provides a sub-cell electroluminescence test device and method for a perovskite-silicon tandem solar cell. The device uses two Si-CCD cameras to capture the luminescence images of the perovskite and silicon sub-cells respectively, realizing fast and accurate detection. By injecting current to excite the battery to emit light, the image processing system identifies defects such as local short circuits, material inhomogeneity and microcracks, and analyzes the resistance coupling effect of the perovskite and silicon sub-cells to conduct long-term stability analysis of the battery. The introduction of this multi-spectral imaging technology solves the limitations of the existing detection technology 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. 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 some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

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

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

[0027] Figure 3It is the electroluminescence (EL) image of the perovskite sub-cell in the perovskite / silicon tandem solar cell provided by the embodiment of the present invention.

[0028] Figure 4 It is the EL image of the silicon sub-cell in the perovskite / silicon tandem solar cell provided by the embodiment of the present invention.

[0029] Among them, 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 implementation manners

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

[0032] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the terms "center", "longitudinal", "transverse", "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] Please refer to Figure 1 , the embodiment of the present invention provides a sub-cell electroluminescence test device for a tandem solar cell, including: a current injection module 110 for injecting current into the battery to be tested to generate electroluminescence; at least two Si-CCD cameras 210, 220 for capturing image information of the battery's luminescence; at least two filters 230, 240 for filtering light of different wavelengths emitted by the battery; a light source compensation device 310 for emitting light of a specific wavelength and injecting it onto the battery; a data acquisition module 410 responsible for receiving the image data collected by the Si-CCD cameras 210, 220 and transmitting it to the output module 420; an output module 420 for receiving the image data of the data acquisition module 410 and performing processing and analysis; and a stage 510 for carrying the battery to be tested.

[0034] Among them:

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

[0036] In some embodiments, the testing device further includes a power supply device with controllable current density, which is connected to the cell to be tested, used to apply a forward bias, and can maintain the voltage for a long time under different current injection densities, so as to observe the change of the luminescence intensity of the perovskite and silicon sub-cells under the bias condition. By dynamically adjusting the current density range, the performance change of the cell under different working conditions can be evaluated.

[0037] Furthermore, the testing device can monitor the degradation of the cell by applying a forward bias for a long time. It is found that the degradation of the cell under the bias condition usually starts from the edge of the cell and gradually spreads to the center. This device can effectively identify the degradation position and its severity of the cell by continuously monitoring the change of the electroluminescence image.

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

[0039] The optical filters 230 and 240 are used to filter light of different wavelengths to distinguish the luminescence of the perovskite and silicon cells. The optical filter 230 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 through; the optical filter 240 is used to block the luminescence of the perovskite layer and only capture the infrared luminescence of the silicon cell.

[0040] The light source compensation device 310 is responsible for detecting the energy lost due to the absorption or scattering of the electroluminescence signal of the bottom cell by the upper cell, and filling the signal attenuation caused by the upper cell occlusion by emitting light of a specific wavelength to enhance 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 the 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, and microcracks in the battery. The analyzed image data can also be used to generate a defect detection report and record the luminescence characteristics and performance differences of the perovskite and silicon sub-cells.

[0043] Please refer to Figure 2 , a method for electroluminescence testing of sub-cells of a tandem solar cell provided by an embodiment of the present invention is carried out using the above device, and includes the 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 excite the electroluminescence phenomenon.

[0045] Specifically, the current injection module 110 can adjust the magnitude of the current to simulate different working conditions and ensure the luminescence characteristics of the battery under different current conditions.

[0046] S2: Use two Si-CCD cameras 210 and 220 to capture the electroluminescence images of the perovskite-silicon tandem solar cell to be tested in cooperation with the filter 230 and the filter 240 respectively.

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

[0048] S3: The light source compensation device 310 detects the luminescence signal loss of the silicon sub-cell and emits a compensation light signal to offset the absorption effect, thereby improving the accuracy of the imaging system and ensuring the clarity and accuracy of the electroluminescence imaging.

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

[0050] Specifically, this analysis can identify common defects in the battery, such as local short circuits, material inhomogeneities, and microcracks. By comparing the luminescence intensity differences between the two, the resistance coupling effect between the sub-cells is further analyzed to detect defects across the sub-cells.

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

[0052] Example 1:

[0053] This embodiment is about the electroluminescence imaging test steps and test results of a perovskite / silicon tandem solar cell, which are carried out by using the imaging device and test method of the present invention. The specific steps are as follows:

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

[0055] S2: Through the light source compensation of a 365 nm monochromatic light-emitting diode, bleach the near-infrared parasitic absorption loss in the tandem cell.

[0056] S3: A narrowband 808 nm CCD camera is used in combination with a 700 nm long-pass filter to collect the luminescence image of the perovskite sub-cell in the tandem cell;

[0057] S4: A narrowband 1050 nm CCD camera is used in combination with an 850 nm long-pass filter to collect the luminescence image of the silicon sub-cell in the tandem cell. Figure 3 and Figure 4 are the EL images of the obtained perovskite sub-cell and silicon sub-cell respectively.

[0058] The present invention provides a sub-cell electroluminescence (EL) imaging test device and test method for 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 the perovskite sub-cell and the silicon sub-cell is achieved, ensuring that the luminescence characteristics of each sub-cell can be separately captured and analyzed. A light source compensation device is added to ensure that the electroluminescence images of both layers of cells can accurately reflect their defect distributions, improving the accuracy and reliability of the test.

[0059] The key technical points of the present invention lie in its filter spectroscopy 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 luminescence images of the perovskite and silicon sub-cells, the resistance coupling effect between the sub-cells is detected, improving the overall detection efficiency and accuracy. The present invention can be applied to on-line quality control in large-scale production, effectively improving the production yield and reliability of perovskite-silicon cells.

Claims

1. A sub-cell electroluminescence test device for a stacked solar cell, characterized in that, Comprising: A current injection module for injecting current into the battery to be tested to generate electroluminescence; At least two Si-CCD cameras for capturing image information of the battery's luminescence; At least two filters for filtering light of different wavelengths emitted by the battery; A light source compensation device for emitting light of a specific wavelength and injecting it onto the battery; A data acquisition module responsible for receiving the image data collected by the Si-CCD cameras and transmitting it to the output module; An output module for receiving the image data of the data acquisition module and performing processing and analysis; A stage for carrying the battery to be tested; The battery to be tested is a perovskite-silicon tandem solar cell; At least two of the Si-CCD cameras are respectively used for capturing the luminescence images filtered by at least two filters; at least one filter is a short-pass filter dedicated to capturing the luminescence of the perovskite cell; at least one filter is a long-pass filter for capturing the luminescence of the silicon cell; The light source compensation device detects the energy lost when the electroluminescence signal of the bottom cell is absorbed or scattered by the intermediate layer when passing through the upper cell, and by emitting light of a specific wavelength, bleaches the signal attenuation caused by the upper cell's occlusion, enhancing the imaging effect of the bottom cell.

2. The sub-cell electroluminescence test device for a stacked solar cell according to claim 1, characterized in that, The test device detects the defect changes of the battery under different operating conditions by adjusting the current density, and respectively obtains the electroluminescence images under different current conditions.

3. The sub-cell electroluminescence test device for a stacked solar cell according to claim 1, characterized in that, The test device further includes a power supply device with controllable current density, connected to the battery to be tested, for applying a forward bias and being able to maintain the voltage for a long time at different current injection densities.

4. The sub-cell electroluminescence test device for a stacked solar cell according to claim 3, characterized in that, The test device monitors the degradation of the battery by applying a forward bias for a long time.

5. The sub-cell electroluminescence test device for a stacked solar cell according to claim 1, characterized in that, The data acquisition module removes noise and adjusts the image contrast through an image processing algorithm to make defect recognition more accurate.

6. The sub-cell electroluminescence test device for a stacked solar cell according to claim 1, wherein The output module is used to generate an analysis result, including identifying local short circuits, material inhomogeneities, and microcrack defects in the battery.

7. A method for testing the electroluminescence of a sub-cell of a tandem solar cell, which is applied to the testing device for the electroluminescence of the sub-cell of the tandem solar cell according to any one of claims 1 to 6 above, characterized in that, Including steps: S1: Using the current injection module to apply a preset current density to the perovskite-silicon tandem solar cell to be tested to stimulate the electroluminescence phenomenon; S2: Using two Si-CCD cameras to respectively cooperate with the filters to capture the electroluminescence images of the perovskite-silicon tandem solar cell to be tested; S3: The light source compensation device detects the loss of the luminescence signal of the silicon sub-cell, and cancels 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 electroluminescence imaging; S4: The data acquisition module conducts a comparative analysis on the luminescence 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 defect location, defect type, and its severity in the battery.

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