Perovskite laminated solar cell detection device and detection method

Abstract

The invention aims to provide a perovskite laminated solar cell detection device and a detection method, which are suitable for performance characterization and quality control of a perovskite laminated solar cell. The invention aims to solve the problem that the series resistance distribution of the perovskite laminated solar cell cannot be rapidly and accurately detected under the condition of no metallization or no electrical contact in the prior art. Through photoluminescence and electroluminescent imaging technologies, in combination with a non-uniform illumination mode generated by digital micromirror equipment, accurate identification of a high series resistance region of the perovskite solar cell is realized, so that reliable data support is provided for process optimization and defect detection, and the detection efficiency and safety are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic testing, and particularly to a perovskite tandem solar cell detection device and a detection method. The present invention is based on a non-uniform illumination non-contact series resistance imaging device and method, which is applicable to the performance characterization and defect detection of perovskite tandem solar cells. Background Art

[0002] Perovskite tandem solar cells have become a hot topic in photovoltaic technology research in recent years due to their excellent optoelectronic properties and potential for low-cost manufacturing. The power conversion efficiency of perovskite tandem solar cells has exceeded 30%, showing broad prospects for commercial applications. However, the practical application of perovskite tandem solar cells still faces the following key challenges: First, the long-term stability is relatively low, making it difficult to meet the long-term use requirements; second, there are problems such as process complexity and performance uniformity in the expansion of device area. In addition, during the production process, since parameters such as series resistance have a significant impact on the cell performance, it is particularly important to accurately and quickly characterize these parameters. Traditional series resistance characterization methods mostly rely on electroluminescence imaging or contact photoluminescence imaging, and these methods usually require metallized cells and electrical contacts. The contact characterization method not only has the problem of potentially damaging the cell, but also may lead to excessive consumption of conductive electrode materials (such as gold). Therefore, in the production line detection of perovskite tandem solar cells, it is of great significance to develop efficient and non-contact characterization techniques.

[0003] Contactless imaging techniques have gradually gained attention in photovoltaic testing. For example, in the existing paper "Comparison of photovoltaic module luminescence imaging techniques: Assessing the influence of lateral currents in high-efficiency device structures", Sulas et al., Solar Energy Materials and Solar Cells, Vol. 192, pp. 81 - 87, April 2019; and "Photoluminescence and electroluminescence imaging of perovskite solar cells", Hameiri et al., Progress in Photovoltaics: Research and Applications, Vol. 23, No. 12, pp. 1697 - 1705, November 2015. In the testing methods disclosed in the above-mentioned literature, these methods can obtain the spatial distribution information of key electrical performance parameters in the battery without electrical contact. However, most of the current contactless imaging techniques are mainly applied to silicon solar cells, and their applications in the field of perovskite tandem solar cells are relatively limited, especially the applications in identifying high-series regions and analyzing defect distributions are not yet mature. In addition, the existing contactless techniques also have certain limitations in realizing real-time detection in the early manufacturing stage of devices. Summary of the Invention

[0004] In view of the deficiencies of the existing technology, the purpose of the present invention is to provide a detection device and method for perovskite tandem solar cells, which are suitable for the performance characterization and quality control of perovskite tandem solar cells. The present invention aims to solve the problem in the existing technology that the series resistance distribution cannot be quickly and accurately detected under the conditions of non-metallization or electrical contact. Through the photoluminescence imaging technique, combined with the non-uniform illumination pattern generated by the digital micromirror device, the accurate identification of the high-series region of the perovskite solar cell is realized, thereby providing reliable data support for process optimization and defect detection, and significantly improving the efficiency and safety of detection.

[0005] The first aspect of the present application provides a perovskite tandem solar cell detection device. The device includes a light source module, a first filter, a cold mirror, a digital micromirror device, a sample stage, a second filter, an imaging module, and an image processing module. The sample stage is used to carry the perovskite tandem solar cell. The light source is emitted by the light source module and sequentially passes through the first filter, the cold mirror, the digital micromirror device, and the perovskite tandem solar cell on the sample stage. After the battery is excited to form electroluminescence, it sequentially passes through the cold mirror, the second filter, and the imaging module. The imaging module captures image information and transmits it to the image processing module. The device of the present invention is used to realize high-resolution resistance imaging of perovskite solar cells. By combining photoluminescence technology with a non-uniform illumination mode, it can quickly identify high series resistance regions without contacting the battery, providing accurate data support for the quality control and process optimization of photovoltaic devices.

[0006] In some embodiments, the light source module in the device can generate short-wave excitation light with a wavelength range of 300 nm to 675 nm, which is used to excite the perovskite photoactive layer in the perovskite tandem cell to generate free electrons and holes.

[0007] In some embodiments, the first filter is a short-wave pass filter, which is used to filter out the long-wave components of the excitation light.

[0008] In some embodiments, the cold mirror can separate the excitation light and the emission signal. It is an optical lens that can reflect the excitation light signal in the ultraviolet and visible light bands and allow the long-wave near-infrared light generated by the perovskite emission to pass through. During use, the lens surface of the cold mirror forms a 45° angle with the optical path of the light source module. The light source module combines the cold mirror and the short-wave pass filter to remove the excess long-wave components, which can ensure the purity of the excitation light and improve the detection accuracy of the photoluminescence signal.

[0009] In some embodiments, the digital micromirror device is composed of a number of tiny mirrors arranged in an array with sizes between a few micrometers and dozens of micrometers to achieve precise optical control. The micromirrors quickly change the tilt angles of a number of mirrors through electrostatic drive. There is a mechanical structure in the digital micromirror device to support the micromirrors, ensuring stability. The digital micromirror device is used to generate a flexible and controllable non-uniform illumination mode. By adjusting the angles of the micromirror chips, the digital micromirror device can form alternating illuminated and non-illuminated regions on the surface of the perovskite solar cell, thereby achieving precise detection of the target high-resistance region.

[0010] In some embodiments, the second filter is a long-wave pass filter, and the long-wave pass filter only captures the photoluminescence signal of the perovskite solar cell, thereby further enhancing the contrast and accuracy of imaging.

[0011] In some embodiments, the imaging module in the device uses a scientific complementary metal-oxide-semiconductor (sCMOS) camera with a resolution of no less than 10 million pixels. This camera can synchronously capture photoluminescence images under multiple lighting conditions and ensure a high signal-to-noise ratio of the images through high dynamic range imaging, providing high-quality data for subsequent resistance distribution analysis.

[0012] In some embodiments, the image processing module includes: a signal enhancement module for enhancing the contrast of the photoluminescence signal; a noise filtering module for removing random noise and environmental interference; and an image analysis module for generating a high-contrast series resistance distribution map through ratio calculation. Through these processing steps, the image processing module can generate a high-contrast series resistance distribution map and accurately identify defect areas in the battery, such as material inhomogeneity, local short circuits, and carrier transport barriers.

[0013] The second aspect of this application provides a method for detecting a perovskite tandem solar cell using the device of the present invention, including the following steps:

[0014] (1) The light source module emits light that sequentially passes through a first filter, a cold mirror, a digital micromirror device, and a perovskite tandem solar cell. A non-uniform illumination pattern is generated through the digital micromirror device, forming alternating illuminated and non-illuminated areas on the battery surface.

[0015] (2) The photoluminescence generated by the radiative recombination of some carriers excited in the illuminated area of the battery and the electroluminescence generated by the diffusion of the un-recombined carriers to the non-illuminated area through the battery electrodes or charge transport layers sequentially pass through the cold mirror, a second filter, and the imaging module.

[0016] (3) The imaging module synchronously captures the photoluminescence image of the illuminated area and the electroluminescence image of the non-illuminated area, and transmits the image information to the image processing module.

[0017] (4) The image processing module analyzes the image and generates a high-contrast spatial position distribution map of the series resistance by calculating the ratio of the spatial position coordinate signals of the photoluminescence and electroluminescence.

[0018] Furthermore, the method further includes: obtaining at least two spatial position distribution maps of the series resistance by adjusting the light power density and illuminated area of the illumination pattern. The illuminated and non-illuminated areas of the multiple spatial position distribution maps of the series resistance are complementary. By analyzing, the resistance information of all areas on the battery surface can be obtained, enabling focus on the analysis of high series resistance areas and identification of defects such as material inhomogeneity, local short circuits, and carrier transport barriers.

[0019] Further, the method further includes: by reducing the illumination area and increasing the illumination intensity, more accurate analysis of the high-resistance region can be performed, providing more detailed data for defect detection. Since the imaging module only captures the electroluminescence generated in the non-illuminated region, reducing the illumination area and increasing the illumination intensity can further improve the electron lateral transport efficiency and electroluminescence stability.

[0020] Furthermore, the device and method of the present invention are applicable to complete perovskite solar cells or semi-finished perovskite solar cells without metallization. Especially in the online monitoring during the early manufacturing stage, they can provide technical support for quality control and defect repair in the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus 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.

[0022] Figure 1 is a schematic structural diagram of the perovskite tandem solar cell detection device of the present invention;

[0023] Figure 2 is a flowchart of the method for detecting a perovskite tandem solar cell by the device of the present invention;

[0024] Figure 3 is a luminescence image of the method for detecting a perovskite tandem solar cell by the device of the present invention.

[0025] Wherein the reference numerals are as follows:

[0026] 510 - Light source module;

[0027] 520 - Imaging module;

[0028] 610 - First filter;

[0029] 620 - Second filter;

[0030] 710 - Digital micromirror device;

[0031] 810 - Cold mirror;

[0032] 910 - Sample stage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] 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.

[0034] In the description of the present invention, unless otherwise specified, "a plurality" 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 drawings, and are 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 understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] Please refer to Figure 1 , the embodiment of the present invention provides a perovskite tandem solar cell detection device for photoluminescence and electroluminescence imaging of perovskite tandem solar cells, and detecting high series resistance regions in the perovskite active layer through imaging analysis to analyze the defect positions of the cell wafers. The device includes the following structures: a light source module 510, a first filter 610, a cold mirror 810, a digital micromirror device 710, a sample stage 910, a second filter 620, an imaging module 520, and an image processing module (not shown in the figure). The sample stage 910 is used to carry the perovskite tandem solar cell. The light source is emitted by the light source module 510 and sequentially passes through the first filter 610, the cold mirror 810, the digital micromirror device 710, and the perovskite tandem solar cell on the sample stage 910. After the battery is excited to form electroluminescence, it sequentially passes through the cold mirror 810, the second filter 620, and the imaging module 520. The imaging module 520 captures image information and transmits it to the image processing module.

[0036] The light source module 510 generates short-wave excitation light with a wavelength range of 300 nm to 675 nm. The excitation light is further changed into a narrower band of excitation light through the first filter 610. Under the adjustment of the cold mirror 810 and the digital micromirror device 710, the excitation light irradiates the surface of the perovskite tandem solar cell, forming alternating illuminated and non-illuminated regions.

[0037] The first filter 610 and the second filter 620 are a short-wave pass filter and a long-wave pass filter respectively. The short-wave pass filter blocks interfering light and only allows the target signal to pass through; the long-wave pass filter is used to further filter non-target signals and improve the signal detection accuracy.

[0038] In some embodiments, the digital micromirror device 710 is composed of a number of tiny mirrors arranged in an array with dimensions between a few micrometers and dozens of micrometers to achieve precise optical control. The mirrors are electrostatically driven to quickly change the tilt angles of a number of mirrors. The structure of the digital micromirror device 710 has a mechanical structure to support the mirrors, ensuring stability. The digital micromirror device 710 is used to generate a flexible and controllable non-uniform illumination pattern. By adjusting the angles of the micromirror elements, the digital micromirror device 710 can form alternating illuminated and non-illuminated regions on the surface of the perovskite solar cell, thereby achieving precise detection of the target high-resistance region.

[0039] Specifically, the size of a single mirror is between 5 - 20 micrometers, the gap between the mirrors is 1 micrometer, and the reflective mirrors on the digital micromirror device chip are distributed in a rectangular array with a resolution between 640×480 and 7680×4320, corresponding to batteries or battery modules with different effective areas.

[0040] The perovskite tandem solar cell carried on the sample stage 910 is a series-connected battery structure obtained by laminating a crystalline silicon sub-cell and a perovskite sub-cell. The light source is injected into the perovskite sub-cell to generate electroluminescence, and the interference light is filtered out by the cold mirror 810 and the filter, so as to form an image on the imaging module 520.

[0041] The cold mirror 810 is an optical lens that can reflect the excitation light signal in the ultraviolet and visible light bands and allow the long-wavelength near-infrared light generated by the perovskite emission to pass through, with a reflection efficiency (short wave) and transmission efficiency (long wave) of >90%.

[0042] During use, the surface of the lens of the cold mirror 810 forms a 45° angle with the optical path of the light source module 510, effectively separating the interference light and improving the detection efficiency of the signal.

[0043] The imaging module 520 uses a complementary metal oxide semiconductor (sCMOS) camera to synchronously capture the photoluminescence images and electroluminescence images of the illuminated and non-illuminated regions. The camera resolution is not less than 10 million pixels to ensure imaging clarity.

[0044] Please refer to Figure 2 , an embodiment of the present invention provides a detection method for a perovskite tandem solar cell, including the following steps:

[0045] S1: The light source module 510 emits a light source that sequentially passes through the first filter 610, the cold mirror 810, the digital micromirror device 710, and the perovskite tandem solar cell on the sample stage 910. The digital micromirror device 710 generates a non-uniform illumination pattern to form alternating illuminated and non-illuminated regions on the surface of the battery;

[0046] S2: The electroluminescence generated by the battery sequentially passes through the cold mirror 810, the second filter 620, and the imaging module 520;

[0047] S3: The imaging module 520 synchronously captures the photoluminescence images of the illuminated and non-illuminated regions, and transmits the image information to the image processing module;

[0048] S4: The image processing module analyzes the images, and generates a high-contrast series resistance distribution map by calculating the ratio of the photoluminescence signals.

[0049] In the method for detecting a perovskite tandem solar cell by the device of the present invention, the excitation light is generated by the light source module, and is changed into monochromatic ultraviolet excitation light through the first filter. The monochromatic ultraviolet excitation light is reflected by the cold mirror and non-uniform illumination is generated on the battery surface by the digital micromirror device. The photons of the excitation light excite the battery illumination area to generate radiative transitions. Among them, some electrons and holes recombine radiatively to generate photoluminescence, and the un-recombined electrons are collected by the electrode (complete battery) or the charge transport layer (semi-finished battery) and transmitted to the non-illuminated area of the battery to form an injection current. Electroluminescence is generated when the injection current, that is, electrons and holes, recombine in the non-illuminated area. The generated near-infrared photoluminescence and electroluminescence are transmitted through the cold mirror and received by the imaging module, and output as a mapped image. As shown in Figure 3 In the perovskite semi-finished battery image, the left part is the photoluminescence of the illuminated area, and the right part is the electroluminescence image generated by recombination. The above process is repeated by alternately changing the illuminated and non-illuminated regions to obtain the electroluminescence image of the entire effective area of the battery.

[0050] The directly emitted light intensity ø detected in the solar cell is positively correlated with its diode voltage V,

[0051] ,

[0052] In the diode model of the solar cell, the voltage drop V s of the equivalent series resistance is

[0053] ,

[0054] ,

[0055] where R s is the series resistance of the battery, J is related to the injection current density and the PL intensity, k is the Boltzmann constant, and T is the thermodynamic temperature. The formula shows that the final electroluminescence intensity is positively correlated with the series resistance of the battery. The image processing module analyzes and calculates the image to obtain the spatial coordinate-related distribution information of the series resistance.

[0056] In some embodiments, the present device and method are also capable of adjusting illumination conditions, including information such as illumination mode, exposure time, and image acquisition parameters.

[0057] By adjusting the optical power density and illumination area of the illumination mode, at least two spatial position distribution maps of the series resistance are obtained. The illuminated and non-illuminated areas of the multiple spatial position distribution maps of the series resistance are complementary. By analyzing the illuminated and non-illuminated areas of all regions on the battery surface, it is possible to focus on analyzing the high-series regions and identify defects such as material inhomogeneity, local short circuits, and carrier transport barriers.

[0058] Specifically, by adjusting the digital micromirror device, the optical power density and illumination area of the illumination mode can be adjusted. The optical power density can be adjusted to 0.1 - 50 mW / cm 2 , and the area ratio of the illumination area in the entire battery area ranges from 110 - 99%.

[0059] Furthermore, by reducing the illumination area and increasing the illumination intensity, more accurate analysis of the high-resistance regions can be carried out, providing more detailed data for defect detection. Since the imaging module only captures the electroluminescence generated in the non-illuminated area, reducing the illumination area and increasing the illumination intensity can further improve the electron lateral transport efficiency and electroluminescence stability. Specifically, by adjusting the light source module and the digital micromirror device, the illumination area and illumination intensity are adjusted. The area ratio of the illumination area in the entire battery area is adjusted to 1 - 10%, and the illumination intensity is adjusted to 50 - 100 mW / cm 2 .

[0060] The present invention provides a perovskite tandem solar cell detection device and detection method. By generating alternating illuminated and non-illuminated areas through a digital micromirror device, combined with a high-resolution sCMOS camera and a multi-layer filter system, precise non-contact detection of the series resistance distribution of perovskite solar cells is achieved. The light source module generates short-wave excitation light, and interference signals are filtered through a cold mirror and a filter system to ensure the purity of capturing target photoluminescence and electroluminescence signals. The device uses a ratio analysis algorithm in the image processing module to generate a high-contrast series resistance distribution map, which can quickly identify defects such as local short circuits, material inhomogeneity, and carrier transport barriers in the battery.

[0061] The dynamic illumination mode and non-contact detection technology of the present invention are particularly suitable for the online quality control of complete cells and uncompleted metallized cells, can provide precise data support in the early production stage, significantly improve the battery detection efficiency and yield, and promote the large-scale industrial application of perovskite solar cells.

Claims

1. A perovskite tandem solar cell detection device, characterized in that Including: A light source module, a first filter, a cold mirror, a digital micromirror device, a sample stage, a second filter, an imaging module, and an image processing module. The sample stage is used to carry a perovskite tandem solar cell. The light source emitted by the light source module passes through the first filter, the cold mirror, the digital micromirror device, and the perovskite tandem solar cell on the sample stage in sequence. After the battery is excited to form electroluminescence, it passes through the cold mirror, the second filter, and the imaging module in sequence. The imaging module captures image information and transmits it to the image processing module.

2. The perovskite tandem solar cell detection device according to claim 1, wherein The light source module can emit short-wavelength light with a wavelength range of 300 nm to 675 nm, and filters out the long-wavelength components with wavelengths exceeding 675 nm through a short-pass filter.

3. The perovskite tandem solar cell detection device according to claim 1, wherein The first filter is a short-pass filter, which is used to filter out the long-wavelength components of the excitation light.

4. The perovskite tandem solar cell detection device according to claim 1, characterized in that, The cold mirror can separate the excitation light and the emission signal. It is an optical lens that can reflect the excitation light signal in the ultraviolet and visible light bands and allow the long-wavelength near-infrared light generated by the perovskite emission to pass through. During use, the surface of the lens of the cold mirror forms a 45° angle with the optical path of the light source module.

5. The perovskite tandem solar cell detection device according to claim 1, wherein The digital micromirror device is composed of a number of tiny mirrors arranged in an array with sizes between a few micrometers and dozens of micrometers, and realizes rapid changes in the tilt angles of a number of mirrors through electrostatic drive.

6. The perovskite tandem solar cell detection device according to claim 1, wherein, The second filter is a long-pass filter, and the long-pass filter only captures the photoluminescence signal of the perovskite solar cell.

7. The perovskite tandem solar cell detection device according to claim 1, characterized in that, The imaging module uses a complementary metal oxide semiconductor camera.

8. The perovskite tandem solar cell detection device according to claim 1, characterized in that, The image processing module includes: a signal enhancement module, which is used to enhance the contrast of the photoluminescence signal; a noise filtering module, which is used to remove random noise and environmental interference; and an image analysis module, which is used to generate a high-contrast series resistance distribution map through ratio calculation.

9. A method for detecting a perovskite tandem solar cell, which is applied to the perovskite tandem solar cell detection device described in any one of the above claims 1-8, and is characterized in that, Including the following steps: (1) The light source module emits light that passes through the first filter, the cold mirror, the digital micromirror device, and the perovskite tandem solar cell in sequence. A non-uniform illumination pattern is generated by the digital micromirror device, forming alternating illuminated and non-illuminated regions on the surface of the battery. (2) The photoluminescence generated by the radiative recombination of some carriers excited in the illuminated region of the battery and the electroluminescence generated by the diffusion of the un-recombined carriers to the non-illuminated region through the battery electrodes or charge transport layers pass through the cold mirror, the second filter, and the imaging module in sequence. (3) The imaging module synchronously captures the photoluminescence image of the illuminated region and the electroluminescence image of the non-illuminated region, and transmits the image information to the image processing module. (4) The image processing module analyzes the image, and generates a high-contrast series resistance spatial position distribution map by calculating the ratio of the photoluminescence and electroluminescence spatial position coordinate signals.

Images