Solar cell short-circuit current density test method, electronic equipment and storage medium

Abstract

The invention relates to the technical field of solar cells, and provides a solar cell short-circuit current density testing method, electronic equipment and a storage medium. The method comprises the following steps: determining external quantum efficiency values of a to-be-detected battery piece under the action of light sources with different wavelengths; the different wavelength light sources comprise a first wavelength light source and a second wavelength light source, and the external quantum efficiency value under the action of the first wavelength light source is determined according to a first electroluminescent image of the to-be-detected battery piece, a second electroluminescent image of the standard battery piece and an external quantum efficiency value of the standard battery piece; the external quantum efficiency value under the action of the second wavelength light source is determined according to the first electroluminescent image and the blackbody radiation spectrum; the first wavelength is smaller than the second wavelength; and determining the short-circuit current density of the to-be-detected battery piece according to the external quantum efficiency values under the action of the light sources with different wavelengths. Therefore, the accuracy of testing the short-circuit current density of the battery piece to be tested can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method for testing the short-circuit current density of solar cells, an electronic device, and a storage medium. Background Technology

[0002] Currently, when testing the short-circuit current density of a solar cell under test, it is necessary to test its external quantum efficiency (EQE), which is usually measured using an external quantum efficiency meter.

[0003] However, when using an external quantum efficiency meter for testing, the probe of the external quantum efficiency meter needs to contact the cell under test to form a circuit, which can easily cause the cell under test to break. In addition, gridless (OBB) cells are difficult to align with the metal electrodes and the test probe, resulting in poor test accuracy. Summary of the Invention

[0004] This application provides a method, electronic device, and storage medium for testing the short-circuit current density of solar cells, which can improve the accuracy of testing the external quantum efficiency of the solar cell under test.

[0005] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, a method for testing the short-circuit current density of a solar cell is provided, comprising: determining the external quantum efficiency value of the solar cell under test under the action of a light source of different wavelengths; the different wavelength light sources include a first wavelength light source and a second wavelength light source, the external quantum efficiency value under the action of the first wavelength light source is determined based on a first electroluminescence image of the solar cell under test, a second electroluminescence image of a standard solar cell, and the external quantum efficiency value of a standard solar cell; the external quantum efficiency value under the action of the second wavelength light source is determined based on the first electroluminescence image and a blackbody radiation spectrum; the first wavelength is shorter than the second wavelength; and the short-circuit current density of the solar cell under test is determined based on the external quantum efficiency values ​​under the action of the different wavelength light sources.

[0006] Based on this scheme, the short-circuit current density of the solar cell under test is determined according to the external quantum efficiency values ​​under different wavelength light sources. Since the different wavelength light sources include a first wavelength light source and a second wavelength light source, the external quantum efficiency value under the first wavelength light source is determined based on the first electroluminescence image of the solar cell under test, the second electroluminescence image of a standard solar cell, and the external quantum efficiency value of the standard solar cell; the external quantum efficiency value under the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum. Therefore, by comparing the two images and combining them with the external quantum efficiency value and blackbody radiation spectrum of the standard solar cell, the short-circuit current density of the solar cell under test can be determined without the probe contacting the metal electrode of the solar cell under test. This eliminates the problem of poor test accuracy caused by inaccurate alignment between the metal electrode and the test probe, enabling non-contact determination of the short-circuit current density of the solar cell under test. Furthermore, since the external quantum efficiency spectrum fluctuates differently in different wavelength ranges, segmented testing of the external quantum efficiency values ​​under different wavelength light sources can further improve the accuracy of determining the short-circuit current density of the solar cell under test.

[0007] In conjunction with the first aspect, in certain embodiments of the first aspect, determining the external quantum efficiency value of the battery cell under test under the action of a light source of different wavelengths includes: determining a first gray value and a second gray value under the action of a first wavelength light source; the first gray value is the average gray value corresponding to a first electroluminescent image, and the second gray value is the average gray value corresponding to a second electroluminescent image; and determining the external quantum efficiency value of the battery cell under test under the action of a first wavelength light source based on the first gray value, the second gray value, and the external quantum efficiency value of a standard battery cell.

[0008] In conjunction with the first aspect, in certain embodiments of the first aspect, the external quantum efficiency value under the action of the first wavelength light source satisfies the following relationship: in, For external quantum efficiency, The first grayscale value, This is the external quantum efficiency value for a standard solar cell. This is the second grayscale value. The wavelength of the light source is denoted as .

[0009] In conjunction with the first aspect, in some embodiments of the first aspect, the battery cell under test includes a first region and a second region, the first region and the second region being arranged alternately. Determining a first grayscale value includes: acquiring a first partial image and a second partial image; the first partial image is an electroluminescent image captured under the condition that a light-receiving area is formed in the first region and an unlight-receiving area is formed in the second region; the second partial image is an electroluminescent image captured under the condition that an unlight-receiving area is formed in the first region and a light-receiving area is formed in the second region; combining the first partial image and the second partial image to obtain a first electroluminescent image; and determining the first grayscale value based on the average grayscale value of the first electroluminescent image.

[0010] In conjunction with the first aspect, in certain embodiments of the first aspect, when the wavelength light source is a second wavelength light source, determining the external quantum efficiency value of the battery cell under test under the action of different wavelength light sources includes: determining the electroluminescence intensity spectrum of the first electroluminescence image under the action of the second wavelength light source; determining the blackbody radiation value under the action of the second wavelength light source based on the blackbody radiation spectrum; and determining the external quantum efficiency value of the battery cell under test under the action of the second wavelength light source based on the electroluminescence intensity spectrum and the blackbody radiation value.

[0011] In conjunction with the first aspect, in certain embodiments of the first aspect, the external quantum efficiency value under the action of the second wavelength light source satisfies the following relationship: in, This is the external quantum efficiency value. This is an electroluminescence intensity spectrum. This represents the blackbody radiation value at a temperature of 300K. The wavelength of the light source is denoted as .

[0012] In conjunction with the first aspect, in some embodiments of the first aspect, the first wavelength ranges from 300 nm to 1000 nm.

[0013] In conjunction with the first aspect, in some embodiments of the first aspect, the second wavelength ranges from 1000 nm to 1200 nm.

[0014] In conjunction with the first aspect, in certain embodiments of the first aspect, determining the short-circuit current density of the solar cell under test based on the external quantum efficiency values ​​under different wavelength light sources includes: The short-circuit current density of the cell under test is determined based on the external quantum efficiency value and short-circuit current density formula under different wavelength light sources. The formula for short-circuit current density satisfies the following relationship: in, Let ρ be the short-circuit current density of the cell under test, and q be the electron charge. The incident photon flux density is 1.5 atmospheres. This is the external quantum efficiency value. The wavelength of the light source is denoted as .

[0015] Secondly, an electronic device is provided for implementing the solar cell short-circuit current density testing method described in the first aspect. This electronic device includes modules, units, or means corresponding to the above method, which can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0016] In conjunction with the second aspect, in some embodiments of the second aspect, the electronic device includes: a determining module and a processing module; The determination module is used to determine the external quantum efficiency value of the battery cell under test under different wavelength light sources; the external quantum efficiency value under the first wavelength light source is determined based on the first electroluminescence image of the battery cell under test, the second electroluminescence image of the standard battery cell, and the external quantum efficiency value of the standard battery cell; the external quantum efficiency value under the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum; the first wavelength is shorter than the second wavelength; the processing module is used to determine the short-circuit current density of the battery cell under test based on the external quantum efficiency values ​​under different wavelength light sources.

[0017] In conjunction with the second aspect, in some embodiments of the second aspect, the determining module is specifically used to: determine a first grayscale value and a second grayscale value under the action of a first wavelength light source; the first grayscale value is the average grayscale value corresponding to the first electroluminescent image, and the second grayscale value is the average grayscale value corresponding to the second electroluminescent image; and determine the external quantum efficiency value of the battery under test under the action of the first wavelength light source based on the first grayscale value, the second grayscale value, and the external quantum efficiency value of a standard battery cell.

[0018] In conjunction with the second aspect, in some embodiments of the second aspect, the external quantum efficiency value under the action of the first wavelength light source satisfies the following relationship: in, For external quantum efficiency, The first grayscale value, This is the external quantum efficiency value for a standard solar cell. This is the second grayscale value. The wavelength of the light source is denoted as .

[0019] In conjunction with the second aspect, in some embodiments of the second aspect, the battery cell under test includes a first region and a second region, which are arranged alternately. The determining module is specifically used for: acquiring a first partial image and a second partial image; the first partial image is an electroluminescent image taken under the condition that the first region forms a light-receiving area and the second region forms an unlight-receiving area; the second partial image is an electroluminescent image taken under the condition that the first region forms an unlight-receiving area and the second region forms a light-receiving area; combining the first partial image and the second partial image to obtain a first electroluminescent image; and determining a first grayscale value based on the average grayscale value of the first electroluminescent image.

[0020] In conjunction with the second aspect, in some embodiments of the second aspect, when the wavelength light source is a second wavelength light source, the determining module is specifically used for: determining the electroluminescence intensity spectrum of the first electroluminescence image under the action of the second wavelength light source; determining the blackbody radiation value under the action of the second wavelength light source based on the blackbody radiation spectrum; and determining the external quantum efficiency value of the battery cell under test under the action of the second wavelength light source based on the electroluminescence intensity spectrum and the blackbody radiation value.

[0021] In conjunction with the second aspect, in some embodiments of the second aspect, the external quantum efficiency value under the action of the second wavelength light source satisfies the following relationship: in, This is the external quantum efficiency value. This is an electroluminescence intensity spectrum. This represents the blackbody radiation value at a temperature of 300K. The wavelength of the light source is denoted as .

[0022] In conjunction with the second aspect, in some embodiments of the second aspect, the first wavelength ranges from 300 nm to 1000 nm.

[0023] In conjunction with the second aspect, in some embodiments of the second aspect, the range of the second wavelength is 1000nm-1200nm.

[0024] In conjunction with the second aspect, in some embodiments of the second aspect, the processing module is specifically used for: The short-circuit current density of the cell under test is determined based on the external quantum efficiency value and short-circuit current density formula under different wavelength light sources. The formula for short-circuit current density satisfies the following relationship: in, Let ρ be the short-circuit current density of the cell under test, and q be the electron charge. The incident photon flux density is 1.5 atmospheres. This is the external quantum efficiency value. The wavelength of the light source is denoted as .

[0025] Thirdly, an electronic device is provided, comprising: at least one processor and a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the methods provided by the first aspect and any possible implementation thereof.

[0026] Fourthly, a computer-readable storage medium is provided, wherein when instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to perform the methods provided in the first aspect and any possible embodiments thereof.

[0027] Fifthly, a computer program product containing instructions is provided that, when run on a computer, enables the computer to perform the methods provided in the first aspect and any possible implementation thereof.

[0028] The technical effects of any one of the second to fifth aspects can be found in the technical effects of the different embodiments of the first aspect described above, and will not be repeated here. Attached Figure Description

[0029] Figure 1 A schematic diagram of a solar cell short-circuit current density testing system provided in this application; Figure 2 A top view of a metal bracket provided in this application; Figure 3 A flowchart illustrating a method for testing the short-circuit current density of a solar cell provided in this application; Figure 4 A schematic diagram of an external quantum efficiency value spectrum provided in this application; Figure 5 A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application; Figure 6 A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application; Figure 7 A schematic diagram of another solar cell short-circuit current density testing system provided in this application; Figure 8 A schematic diagram of another solar cell short-circuit current density testing system provided in this application; Figure 9 A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application; Figure 10 A schematic diagram of the structure of an electronic device provided in this application; Figure 11 A schematic diagram of the structure of another electronic device provided in this application. Detailed Implementation

[0030] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0031] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0032] In this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being better or more advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0033] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0034] It is understood that in this application, "when," "if," and "if" all refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require that there must be a judgment action when implemented, nor do they imply any other limitations.

[0035] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the electronic devices given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0036] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments and implementation methods of the various embodiments in this application, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the implementation methods of the various embodiments are consistent and can be mutually referenced. The technical features in different embodiments and between the implementation methods of the various embodiments can be combined according to their inherent logical relationships to form new embodiments, implementation methods, implementation methods, or implementation approaches. The following embodiments of this application do not constitute a limitation on the scope of protection of this application.

[0037] Currently, when testing the short-circuit current density of a solar cell under test, it is necessary to test the external quantum efficiency of the solar cell under test, which usually needs to be tested with the help of an external quantum efficiency meter.

[0038] However, when using an external quantum efficiency meter for testing, the probe of the external quantum efficiency meter needs to contact the cell under test to form a circuit, which can easily cause the cell under test to break. In addition, gridless (OBB) cells are difficult to align with the metal electrodes and the test probe, resulting in poor test accuracy.

[0039] To address the aforementioned problems, this application provides a method for testing the short-circuit current density of solar cells. Figure 1 This application provides a schematic diagram of a solar cell short-circuit current density testing system. The method can be applied to… Figure 1 The solar cell short-circuit current density testing system is shown. Figure 1 As shown, the solar cell short-circuit current density testing system may include electronic device 101, image acquisition device 102, EL spectrum acquisition device 103, light source controller 104, light source 105, dark compartment 106, drive motor 107 and metal bracket 108.

[0040] The electronic device 101 is used to perform the solar cell short-circuit current density test method provided in this application. The electronic device 101 is connected to the image acquisition device 102, the EL spectrum acquisition device 103, the light source controller 104, and the drive motor 107.

[0041] Image acquisition device 102 is used to acquire a first electroluminescent image value image of the battery cell under test and a second electroluminescent image of a standard battery cell, and send the first electroluminescent image value image and the second electroluminescent image to electronic device 101, or send a first grayscale value determined based on the first electroluminescent image value image and a first grayscale value determined based on the second electroluminescent image value image.

[0042] Optionally, the image acquisition device 102 may be equipped with a CCD camera (InGaAs) with a 1000nm long-pass filter mounted on the lens.

[0043] The EL spectrum acquisition device 103 is used to acquire the EL spectrum of the battery cell under test, that is, the electroluminescence intensity of the first electroluminescence image under the action of different wavelength light sources, and send the EL spectrum to the electronic device 101.

[0044] Optionally, the EL spectrum acquisition device 103 can be a spectrometer with optical fiber.

[0045] The light source controller 104 is used to control the light source 105 to generate monochromatic light of a specific wavelength.

[0046] The external light source controller 104 of the control light source 105 is used to emit monochromatic light of a specific wavelength to the cell under test so that the cell under test emits light.

[0047] Optionally, the control light source 105 can be an LED light bar with R, G, and B three-color light strips, a laser light source, etc.

[0048] Optionally, the control light source 105 can emit monochromatic light with a wavelength range of 300 nm to 1200 nm.

[0049] The hidden compartment 106 is fixed on a square metal bracket, and its size, number, and spacing can be set according to actual needs. A light source 105 is installed in the hidden compartment.

[0050] Figure 2 A top view of a metal bracket 108 is shown. A drive motor 107 is connected to the metal bracket 108 by bolts. The drive electrode 107 can drive the metal bracket 108 to adjust the relative position of the dark compartment 106 and the battery cell under test.

[0051] The standard solar cell is a solar cell of the same type with known external quantum efficiency, and uses the same test light source and dark grid as the solar cell under test.

[0052] Optional, Figure 1In the solar cell short-circuit current density test system shown, the type of cell under test can include 0BB, MBB IBC, ABC, HPBC, PERC, TBC, TOPcon, HJT or perovskite tandem cells, and this application does not impose specific restrictions on this.

[0053] Optional, Figure 1 In the solar cell short-circuit current density testing system shown, the cell under test can be a non-metallized cell.

[0054] Optional, Figure 1 In the solar cell short-circuit current density testing system shown, the image acquisition device 102 can also be an image acquisition device that can detect the luminescence characteristics of Si-based photovoltaic cells, such as InGaAs, InSb, or HgCdTd. Alternatively, the image acquisition device can also be an image acquisition device that can acquire radiation from other types of semiconductors (e.g., perovskite semiconductors). This application does not impose any specific limitations on this.

[0055] In some embodiments, Figure 1 In the solar cell short-circuit current density testing system shown, the electronic equipment and the image acquisition equipment can be integrated into the same device, or the electronic equipment and the image acquisition equipment can be independent devices. This application does not impose any specific restrictions on this.

[0056] The following description, with reference to the accompanying drawings, uses the application of the solar cell short-circuit current density testing method to electronic devices as an example to illustrate the solar cell short-circuit current density testing method provided in this application.

[0057] Figure 3 A flowchart illustrating a method for testing the short-circuit current density of a solar cell provided in this application is shown below. Figure 3 As shown, the method includes the following steps: S301. Determine the external quantum efficiency value of the battery cell under test under different wavelength light sources.

[0058] Among them, the different wavelength light sources include a first wavelength light source and a second wavelength light source. The external quantum efficiency value under the action of the first wavelength light source is determined based on the first electroluminescence image of the battery cell under test, the second electroluminescence image of the standard battery cell, and the external quantum efficiency value of the standard battery cell. The external quantum efficiency value under the action of the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum. The first wavelength is shorter than the second wavelength.

[0059] It should be noted that the first wavelength light source and the second wavelength light source can be light emitted by the same light source device according to wavelength requirements. This light source device can be... Figure 1 The light source in it is 105.

[0060] It should be noted that the first wavelength range is 300nm-1000nm. The second wavelength range is 1000nm-1200nm. That is, Figure 1 The light source 105 in the light source can emit light with a wavelength range of at least 300nm-1200nm.

[0061] It should be noted that the light source 105 can be set as needed, and this application does not impose specific restrictions on it.

[0062] Light intensity, also known as luminous intensity or radiant intensity, is a physical quantity used to describe the luminous flux radiated by a light source within a unit solid angle. It measures the strength of the light emitted by a light source.

[0063] For example, the light intensity value can be the light intensity value that makes the battery cell under test reach its maximum power. Of course, the light intensity value can also have other values, and this application does not make any specific restrictions on this.

[0064] As one possible implementation, the light source device can be controlled to emit several representative first wavelength light sources with wavelengths in the range of 300nm-1000nm, and the light source device can be controlled to emit several representative second wavelength light sources with wavelengths in the range of 1000nm-1200nm. The electroluminescence image of the battery cell under test under the action of each different wavelength light source can be acquired by the image acquisition device and used as the first electroluminescence image. Correspondingly, the electroluminescence images of the standard solar cell under the action of each different wavelength light source are acquired by the image acquisition device and used as the second electroluminescence image; Furthermore, under the action of the first wavelength light source (300nm-1000nm), the external quantum efficiency value of the battery under test is calculated based on the first electroluminescence image, the second electroluminescence image and the external quantum efficiency value of the standard battery cell. Under the influence of a second wavelength light source (1000nm-1200nm), the external quantum efficiency value of the tested solar cell is calculated based on the first electroluminescence image and blackbody radiation spectrum.

[0065] It should be noted that several representative first-wavelength light sources can be pre-set.

[0066] Optionally, the first wavelength can be 365nm, 395nm, 420nm, 435nm, 455nm, 505nm, 590nm, 660nm, 760nm, 860nm, 950nm, etc.

[0067] Optionally, based on the external quantum efficiency values ​​of the cell under test under the action of the first wavelength light source (300nm-1000nm) and the external quantum efficiency values ​​of the cell under test under the action of the second wavelength light source (1000nm-1200nm), a graph of the external quantum efficiency values ​​of the cell under test can be obtained by stitching together the graphs.

[0068] In one example, the spliced ​​external quantum efficiency spectrum of the solar cell under test can be... Figure 4 As shown in the figure, the horizontal axis of the external quantum efficiency spectrum represents wavelength, and the vertical axis represents the external quantum efficiency value (EQE).

[0069] It should be noted that the specific details of this step can be found in the following sections, and will not be repeated here.

[0070] S302. Determine the short-circuit current density of the cell under test based on the external quantum efficiency value under different wavelength light sources.

[0071] It should be noted that short-circuit current density can also be called integral current density.

[0072] As one possible approach, electronic devices can determine the short-circuit current density of the cell under test based on the external quantum efficiency value and the short-circuit current density formula under different wavelength light sources. The formula for short-circuit current density satisfies the following relationship: in, Let q be the short-circuit current density of the cell under test, and q be the electron charge (1.6 × 10⁻⁶). -19 C), Incident photon flux density at 1.5 atmospheres (unit: photon number·m) -2 ·s -1 ·nm -1 ), This is the external quantum efficiency value. The wavelength of the light source is denoted as .

[0073] It needs to be explained that, in When the first wavelength is 300nm-1000nm The calculation method, and When the second wavelength is 1000nm-1200nm The calculation methods differ, and you can refer to the explanation in the following sections for details, which will not be elaborated here.

[0074] Based on S301-S302, this scheme determines the short-circuit current density of the battery cell under test based on the external quantum efficiency values ​​under different wavelength light sources. Since the different wavelength light sources include a first wavelength light source and a second wavelength light source, the external quantum efficiency value under the first wavelength light source is determined based on the first electroluminescence image of the battery cell under test, the second electroluminescence image of a standard battery cell, and the external quantum efficiency value of the standard battery cell. The external quantum efficiency value under the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum. Therefore, by comparing the two images and combining them with the external quantum efficiency value and blackbody radiation spectrum of the standard battery cell, the short-circuit current density of the battery cell under test can be determined without the probe contacting the metal electrode of the battery cell under test. This eliminates the problem of poor test accuracy caused by inaccurate alignment between the metal electrode and the test probe, enabling non-contact determination of the short-circuit current density of the battery cell under test. Furthermore, since the external quantum efficiency spectrum fluctuates differently in different wavelength ranges, segmented testing of the external quantum efficiency values ​​under different wavelength light sources can further improve the accuracy of determining the short-circuit current density of the battery cell under test.

[0075] The above is a general description of the solar cell short-circuit current density testing method provided in this application. The following will provide a further description of the solar cell short-circuit current density testing method provided in this application with reference to the accompanying drawings.

[0076] In one design, Figure 5 A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application is shown below. Figure 5 As shown in the specific embodiment of this application, when the wavelength light source is a first wavelength light source, in order to determine the external quantum efficiency value of the battery cell under test under different wavelength light sources, the above-mentioned S301 specifically includes the following steps: S401. Determine the first grayscale value and the second grayscale value under the action of the first wavelength light source.

[0077] Wherein, the first gray value is the average gray value corresponding to the first electroluminescent image, and the second gray value is the average gray value corresponding to the second electroluminescent image.

[0078] As one possible implementation, the electronic device can determine the total number of pixels in the first electroluminescent image, the sum of the gray values ​​of each pixel, and determine the ratio of the sum of the gray values ​​of each pixel to the total number of pixels as the first gray value. Accordingly, the total number of pixels in the second electroluminescent image and the sum of the gray values ​​of each pixel are determined, and the ratio of the sum of the gray values ​​of each pixel to the total number of pixels is determined as the second gray value.

[0079] As another possible implementation, the electronic device can determine the total number of pixels in the first electroluminescent image after shielding the special area, as well as the sum of the gray values ​​of each pixel after shielding the special area, and determine the ratio of the sum of the gray values ​​of each pixel to the total number of pixels as the first gray value.

[0080] Accordingly, the total number of pixels in the second electroluminescent image after shielding the special area is determined, as well as the sum of the gray values ​​of each pixel after shielding the special area is determined, and the ratio of the sum of the gray values ​​of each pixel to the total number of pixels is determined as the second gray value.

[0081] For example, special areas may include one or more of the following: areas corresponding to pad points, mark points, cut lines, edge bus lines, IV test points, etc. of the cell under test.

[0082] S402. Determine the external quantum efficiency value of the cell under test under the action of the first wavelength light source based on the first gray value, the second gray value and the external quantum efficiency value of the standard cell.

[0083] It should be noted that the external quantum efficiency value under the action of the first wavelength light source satisfies the following relationship: in, For external quantum efficiency, The first grayscale value, This is the external quantum efficiency value for a standard solar cell. This is the second grayscale value. The wavelength of the light source is denoted as .

[0084] In one example, the first wavelength is 300nm-1000nm. The electronic device can calculate the external quantum efficiency value of the first wavelength light source at wavelengths of 365nm, 395nm, 420nm, 435nm, 455nm, 505nm, 590nm, 660nm, 760nm, 860nm, and 950nm, respectively, and then obtain the EQE spectrum of the cell under test in the 300nm-1000nm range.

[0085] Based on S401-S402, the external quantum efficiency value of the cell under test at that wavelength is determined by combining the average gray value of the two electroluminescent images with the external quantum efficiency value of the standard cell. In this way, there is no need for the probe to contact the metal electrode of the cell under test, and there is no problem of poor test accuracy caused by inaccurate alignment between the metal electrode and the test probe. It can realize non-contact determination of the short-circuit current density of the cell under test, thereby improving the accuracy of determining the short-circuit current density.

[0086] In one design, Figure 6A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application is shown below. Figure 6 As shown in the specific embodiment of this application, the battery cell under test includes a first region and a second region, which are arranged alternately. In order to determine the first grayscale value, this application may further include the following steps: S501, Obtain the first part image and the second part image.

[0087] The first image is an electroluminescent image taken under the condition that a light-receiving area is formed in the first region and an unlight-receiving area is formed in the second region; the second image is an electroluminescent image taken under the condition that an unlight-receiving area is formed in the first region and a light-receiving area is formed in the second region. As one possible implementation, when acquiring the first partial image, the second area can be blocked, and the battery cell under test can be illuminated to form an illuminated area in the first area and an unilluminated area in the second area. Then, the first partial image can be captured by taking a picture. Correspondingly, when acquiring the second partial image, the first area can be blocked, and the battery cell under test can be illuminated to form an unlit area in the first area and an illuminated area in the second area. Then, the second partial image can be captured by taking a picture.

[0088] In one example, combining Figure 7 The drive motor 107 first moves the metal bracket 108 to the first position, and the light source 105 illuminates the battery cell to be tested. At this time, a light-receiving area is formed in the first region and an unlight-receiving area is formed in the second region. The image acquisition device 102 captures an EL image of the first position to obtain the first part image. Next, combined Figure 8 The drive motor 107 moves the metal bracket 108 to the second position, the light source 105 illuminates the battery cell under test, and the image acquisition device 102 captures an EL image of the second position to obtain the second partial image. The dark areas or exposed battery cell areas of the first and second positions are complementary.

[0089] S502. Combine the first and second part images to obtain the first electroluminescent image.

[0090] As one possible implementation, the electronic device can align the first partial image and the second partial image, and then merge the first partial image and the second partial image to obtain the first electroluminescent image.

[0091] In some embodiments, after obtaining the first electroluminescent image, it is also possible to determine whether the battery cell has defects such as black spots or broken grids based on the first electroluminescent image.

[0092] The methods for determining whether solar cells have defects such as black spots or broken grids can be found in existing technologies and will not be elaborated here.

[0093] In this way, by using the combined first electroluminescent image, various defects in the solar cells can be accurately detected.

[0094] S503. Determine the first gray value based on the average gray value of the first electroluminescent image.

[0095] Understandably, by controlling the lighting conditions in different areas and capturing two partial images, the combined images eliminate the influence of uneven local illumination, resulting in a complete and uniform first electroluminescence image. This allows for the precise extraction of interference-free grayscale values, avoiding measurement deviations caused by local overexposure / underexposure, and improving the accuracy of external quantum efficiency calculations. Furthermore, it enables EQE data testing of the entire solar cell surface, overcoming the limitation of conventional EQE testing which can only test local areas, and comprehensively reflecting the cell's performance.

[0096] In one design, Figure 9 A flowchart illustrating another method for testing the short-circuit current density of solar cells provided in this application is shown below. Figure 9 As shown in the specific embodiment of this application, when the wavelength light source is a second wavelength light source, in order to determine the external quantum efficiency value of the battery cell under test under the action of different wavelength light sources, S301 of this application may specifically include the following multiple steps: S601. Determine the electroluminescence intensity of the first electroluminescent image under the action of the second wavelength light source.

[0097] As one possible approach, electroluminescence (EL) photons from the cell under test can be collected via an optical fiber connected to a spectrometer, and the EL spectrum can be obtained by analyzing the spectrometer. Based on the EL spectrum, the electroluminescence intensity of the first electroluminescence image under the action of a second wavelength light source can be determined.

[0098] It should be noted that the horizontal axis of the EL spectrum represents wavelength, and the vertical axis represents electroluminescence intensity.

[0099] The second wavelength is 1000nm-1200nm, which means that the electroluminescence intensity of the first electroluminescence image under the action of a light source with a wavelength of 1000nm-1200nm can be determined based on the EL spectrum.

[0100] S602. Determine the blackbody radiation value under the action of the second wavelength light source based on the blackbody radiation spectrum.

[0101] The blackbody radiation spectrum is the blackbody radiation spectrum at a temperature of 300K. The horizontal axis of the blackbody radiation spectrum represents wavelength, and the vertical axis represents the blackbody radiation value.

[0102] The second wavelength is 1000nm-1200nm, which means that the blackbody radiation value under the action of a light source with a wavelength of 1000nm-1200nm can be determined based on the blackbody radiation spectrum.

[0103] S603. Determine the external quantum efficiency value of the battery cell under test under the action of the second wavelength light source based on the electroluminescence intensity and blackbody radiation value.

[0104] It should be noted that the external quantum efficiency value under the action of the second wavelength light source satisfies the following relationship: in, This is the external quantum efficiency value. This is an electroluminescence intensity spectrum. This represents the blackbody radiation value at a temperature of 300K. The wavelength of the light source is denoted as .

[0105] The second wavelength is 1000nm-1200nm, that is, the external quantum efficiency value under the action of a light source with a wavelength of 1000nm-1200nm can be determined based on the above formula.

[0106] Understandably, by separating the electroluminescence intensity from the blackbody radiation value, eliminating environmental thermal radiation interference, and using the blackbody radiation spectrum as a reference for calibration, the anti-interference capability and accuracy of external quantum efficiency measurement can be significantly improved.

[0107] The above mainly describes the solution provided by the embodiments of this application from the perspective of an electronic device performing a method for testing the short-circuit current density of solar cells. To achieve the above functions, the electronic device includes corresponding hardware structures and / or software modules for performing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0108] This application embodiment can divide the electronic device into functional modules according to the above method example. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. Optionally, the module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. Furthermore, "module" here can refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, integrated logic circuits, and / or other devices that can provide the above functions.

[0109] When using functional module division Figure 10 A schematic diagram of the structure of an electronic device is shown. Figure 10 As shown, the electronic device 70 includes a determining module 701 and a processing module 702.

[0110] In some embodiments, the electronic device 70 may further include a storage module ( Figure 10 (not shown in the image) is used to store program instructions and data.

[0111] The determination module 701 is used to determine the external quantum efficiency value of the battery cell under test under different wavelength light sources; the external quantum efficiency value under the first wavelength light source is determined based on the first electroluminescence image of the battery cell under test, the second electroluminescence image of the standard battery cell, and the external quantum efficiency value of the standard battery cell; the external quantum efficiency value under the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum; the first wavelength is shorter than the second wavelength; the processing module 702 is also used to determine the short-circuit current density of the battery cell under test based on the external quantum efficiency values ​​under different wavelength light sources.

[0112] Optionally, the determining module 701 is specifically used to: determine a first gray value and a second gray value under the action of a first wavelength light source; the first gray value is the average gray value corresponding to the first electroluminescent image, and the second gray value is the average gray value corresponding to the second electroluminescent image; and determine the external quantum efficiency value of the battery under test under the action of a first wavelength light source based on the first gray value, the second gray value, and the external quantum efficiency value of a standard battery cell.

[0113] Optionally, the external quantum efficiency value under the action of the first wavelength light source satisfies the following relationship: in, For external quantum efficiency, The first grayscale value, This is the external quantum efficiency value for a standard solar cell. This is the second grayscale value. The wavelength of the light source is denoted as .

[0114] Optionally, the battery cell under test includes a first region and a second region, which are arranged alternately. The determining module 701 is specifically used for: acquiring a first partial image and a second partial image; the first partial image is an electroluminescent image taken under the condition that the first region forms a light-receiving area and the second region forms an unlight-receiving area; the second partial image is an electroluminescent image taken under the condition that the first region forms an unlight-receiving area and the second region forms a light-receiving area; combining the first partial image and the second partial image to obtain a first electroluminescent image; and determining a first gray value based on the average gray value of the first electroluminescent image.

[0115] Optionally, when the wavelength light source is a second wavelength light source, the determining module 701 is specifically used to: determine the electroluminescence intensity of the first electroluminescence image under the action of the second wavelength light source; determine the blackbody radiation value under the action of the second wavelength light source according to the blackbody radiation spectrum; and determine the external quantum efficiency value of the battery cell under test under the action of the second wavelength light source according to the electroluminescence intensity and the blackbody radiation value.

[0116] Optionally, the external quantum efficiency value under the action of the second wavelength light source satisfies the following relationship: in, This is the external quantum efficiency value. This is an electroluminescence intensity spectrum. This represents the blackbody radiation value at a temperature of 300K. The wavelength of the light source is denoted as .

[0117] Optionally, the first wavelength ranges from 300nm to 1000nm.

[0118] Optionally, the second wavelength ranges from 1000nm to 1200nm.

[0119] Optionally, the processing module 702 is specifically used to: determine the short-circuit current density of the cell under test based on the external quantum efficiency value and short-circuit current density formula under different wavelength light sources; The formula for short-circuit current density satisfies the following relationship: in, Let ρ be the short-circuit current density of the cell under test, and q be the electron charge. The incident photon flux density is 1.5 atmospheres. This is the external quantum efficiency value. The wavelength of the light source is denoted as .

[0120] All relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0121] When the functions of the above modules are implemented in hardware... Figure 11 A schematic diagram of the structure of yet another electronic device is shown. For example... Figure 11 As shown, the electronic device 80 includes a processor 801, a memory 802, and a bus 803. The processor 801 and the memory 802 can be connected via the bus 803.

[0122] Processor 801 is the control center of electronic device 80. It can be a single processor or a collective term for multiple processing elements. For example, processor 801 can be a general-purpose central processing unit (CPU) or other general-purpose processors. Among them, the general-purpose processor can be a microprocessor or any conventional processor.

[0123] As one embodiment, processor 801 may include one or more CPUs, for example Figure 11 CPU 0 and CPU 1 are shown in the diagram.

[0124] The memory 802 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0125] As one possible implementation, the memory 802 can exist independently of the processor 801. The memory 802 can be connected to the processor 801 via a bus 803 and is used to store instructions or program code. When the processor 801 calls and executes the instructions or program code stored in the memory 802, it can implement the solar cell short-circuit current density testing method provided in this application embodiment.

[0126] In another possible implementation, the memory 802 can also be integrated with the processor 801.

[0127] The 803 bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. This bus can be divided into address bus, data bus, and control bus, etc. For ease of representation, Figure 11 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0128] It should be pointed out that, Figure 11 The structure shown does not constitute a limitation on the electronic device 80. Except... Figure 11 In addition to the components shown, the electronic device 80 may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0129] As an example, combined Figure 4 The functions implemented by the acquisition module 501 and the processing module 502 in the electronic device 50 are the same as those of the acquisition module 501 and the processing module 502. Figure 11 The processor 801 in it has the same function.

[0130] Optional, such as Figure 11 As shown, the electronic device 80 provided in this application embodiment may further include a communication interface 804.

[0131] Communication interface 804 is used to connect to other devices via a communication network. This communication network can be Ethernet, a wireless access network, a wireless local area network (WLAN), etc. Communication interface 804 may include a receiving unit for receiving data and a transmitting unit for transmitting data.

[0132] In one possible implementation, the communication interface 804 in the electronic device 80 provided in this application embodiment can also be integrated into the processor 801, and this application embodiment does not specifically limit this.

[0133] As one possible product form, the electronic device of the present application embodiment can also be implemented using the following: one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing the various functions described throughout this application.

[0134] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0135] This application also provides a computer-readable storage medium storing a computer program or instructions thereon, which, when executed, causes a computer to perform the various steps in the method flow shown in the above method embodiments.

[0136] Embodiments of this application provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the various steps in the method flow shown in the above-described method embodiments.

[0137] This application provides a chip system, including: a processor and an interface circuit; the interface circuit is used to receive computer programs or instructions and transmit them to the processor; the processor is used to execute the computer programs or instructions so that the chip system performs each step in the method flow shown in the above method embodiments.

[0138] The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), registers, hard disks, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing, or any other form of computer-readable storage medium in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may reside in a purpose-specific ASIC. In the embodiments of this application, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0139] Since the electronic device, computer-readable storage medium, and computer program product provided in this embodiment can be applied to the solar cell short-circuit current density testing method provided in this embodiment, the technical effects that can be obtained can also be referred to the above method embodiments. The embodiments of this application will not be repeated here.

[0140] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0141] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A method for testing the short-circuit current density of a solar cell, characterized in that, The method includes: The external quantum efficiency (EQE) values ​​of the tested solar cell under different wavelength light sources are determined. These different wavelength light sources include a first wavelength light source and a second wavelength light source. The EQE value under the first wavelength light source is determined based on a first electroluminescence image of the tested solar cell, a second electroluminescence image of a standard solar cell, and the EQE value of the standard solar cell. The EQE value under the second wavelength light source is determined based on the first electroluminescence image and a blackbody radiation spectrum. The first wavelength is shorter than the second wavelength. The short-circuit current density of the battery cell under test is determined based on the external quantum efficiency values ​​under the action of different wavelength light sources.

2. The method according to claim 1, characterized in that, When the wavelength light source is the first wavelength light source, determining the external quantum efficiency value of the battery cell under test under different wavelength light sources includes: Determine the first grayscale value and the second grayscale value under the action of the first wavelength light source; the first grayscale value is the average grayscale value corresponding to the first electroluminescent image, and the second grayscale value is the average grayscale value corresponding to the second electroluminescent image. The external quantum efficiency value of the battery under test under the first wavelength light source is determined based on the first gray value, the second gray value, and the external quantum efficiency value of the standard battery cell.

3. The method according to claim 2, characterized in that, The external quantum efficiency value under the action of the first wavelength light source satisfies the following relationship: in, The external quantum efficiency is given. The first grayscale value, The external quantum efficiency value of the standard solar cell is given. This is the second grayscale value. The wavelength of the light source is denoted as .

4. The method according to claim 2, characterized in that, The battery cell under test includes a first region and a second region, which are arranged alternately. Determining the first grayscale value includes: Acquire a first partial image and a second partial image; the first partial image is an electroluminescent image captured under the condition that a light-receiving area is formed in the first region and an unlight-receiving area is formed in the second region; the second partial image is an electroluminescent image captured under the condition that an unlight-receiving area is formed in the first region and a light-receiving area is formed in the second region. The first segment image and the second segment image are combined to obtain the first electroluminescent image; The first gray value is determined based on the average gray value of the first electroluminescent image.

5. The method according to claim 1, characterized in that, When the wavelength light source is the second wavelength light source, determining the external quantum efficiency value of the battery cell under test under different wavelength light sources includes: Determine the electroluminescence intensity spectrum of the first electroluminescence image under the action of the second wavelength light source; Based on the blackbody radiation spectrum, determine the blackbody radiation value under the action of the second wavelength light source; Based on the electroluminescence intensity spectrum and blackbody radiation value, the external quantum efficiency value of the battery cell under test under the action of the second wavelength light source is determined.

6. The method according to claim 5, characterized in that, The external quantum efficiency value under the second wavelength light source satisfies the following relationship: in, The external quantum efficiency value is given. The electroluminescence intensity spectrum is shown. The blackbody radiation value at a temperature of 300K. The wavelength of the light source is denoted as .

7. The method according to claim 1, characterized in that, The first wavelength ranges from 300nm to 1000nm.

8. The method according to claim 1, characterized in that, The second wavelength ranges from 1000nm to 1200nm.

9. The method according to claim 1, characterized in that, The step of determining the short-circuit current density of the battery cell under test based on the external quantum efficiency values ​​under the action of different wavelength light sources includes: Based on the external quantum efficiency values ​​under different wavelength light sources and the short-circuit current density formula, the short-circuit current density of the battery cell under test is determined. The formula for short-circuit current density satisfies the following relationship: in, Let q be the short-circuit current density of the battery cell under test, and q be the electron charge. The incident photon flux density is 1.5 atmospheres. The external quantum efficiency value is given. The wavelength of the light source is denoted as .

10. An electronic device, characterized in that, The electronic device includes: a determining module and a processing module; The determining module is used to determine the external quantum efficiency value of the battery cell under test under different wavelength light sources; the external quantum efficiency value under the first wavelength light source is determined based on the first electroluminescence image of the battery cell under test, the second electroluminescence image of the standard battery cell, and the external quantum efficiency value of the standard battery cell; the external quantum efficiency value under the second wavelength light source is determined based on the first electroluminescence image and the blackbody radiation spectrum; the first wavelength is less than the second wavelength; The processing module is used to determine the short-circuit current density of the battery cell under test based on the external quantum efficiency values ​​under the action of the different wavelength light sources.

11. An electronic device, characterized in that, The electronic device includes: a processor coupled to a memory for storing programs or instructions that, when executed by the processor, cause the electronic device to perform the method as described in any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, they cause the computer to perform the method as described in any one of claims 1 to 9.

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