Method, device, equipment and system for evaluating attenuation degree of thin film solar cell

Abstract

The invention relates to the technical field of thin film solar cell detection, and discloses a method, device, equipment and system for evaluating the attenuation degree of a thin film solar cell, and the method comprises the steps: continuously transmitting laser pulses to the same test point on the surface of a to-be-detected cell sample, and ablating and exciting the sample layer by layer, and obtaining laser-induced breakdown spectrums at different depths from the upper surface of the sample so as to obtain types and concentrations of elements contained at different depths of the sample. And evaluating the attenuation degree of the to-be-tested battery based on the quantitative distribution condition of the diffusible elements along the thickness direction of the sample battery. On the basis of the laser-induced breakdown spectroscopy technology, the attenuation condition of the battery can be rapidly evaluated from the microscopic mechanism level.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thin-film solar cell detection, and particularly relates to a method, device, equipment and system for evaluating the attenuation degree of a thin-film solar cell. BACKGROUND

[0002] A thin-film solar cell is a cell prepared from several layers of thin films. In a long-term use process, the performance of the thin-film solar cell gradually decreases due to a harsh use environment, material aging, thermal cycling and the like. In order to improve the service life and efficiency of the thin-film solar cell, the attenuation mechanism of the thin-film solar cell needs to be researched.

[0003] Currently, a commonly used detection method such as electrochemical impedance spectroscopy and photoluminescence can provide reference information for cell performance evaluation to a certain extent, but also has limitations that cannot be ignored. The main problem is that these traditional methods are difficult to quantitatively evaluate and carefully analyze the attenuation degree of the thin-film solar cell from the micro level of element diffusion. Element diffusion is the core inducement of the failure and shortened life of the thin-film solar cell, and has a very profound impact on the long-term stability of the thin-film solar cell. In view of this, it is urgent to develop a new method for accurately evaluating the attenuation of the thin-film solar cell based on the degree of element diffusion, and to fill the gap in the micro level evaluation of the existing detection means. SUMMARY

[0004] In view of this, the present application provides a method, device, equipment and system for evaluating the attenuation degree of a thin-film solar cell, to solve the problem that the prior art lacks a method for evaluating the attenuation of a thin-film solar cell based on the degree of element diffusion.

[0005] In a first aspect, the present application provides a method for evaluating the attenuation degree of a thin-film solar cell, comprising:

[0006] controlling a pulsed laser to continuously emit laser pulses, the laser pulses being transmitted to a test point on the surface of a battery sample to be tested, and the battery sample to be tested containing different functional layers, so as to perform layer-by-layer ablation and excitation, generate plasma, collect the plasma radiation generated by the battery to be tested, and transmit the plasma radiation to a spectrometer to obtain the spectrum of the battery sample to be tested at different depths along the thickness direction of the battery at the current test point, wherein the thickness direction of the battery is parallel to the stacking direction of the several functional layers in the battery sample to be tested;

[0007] controlling the sample table to move the battery sample to be tested to the next test point, again emitting the same number of laser pulses, and repeating the above steps until the spectrum collection of all test points is completed;

[0008] The attenuation degree of the battery sample to be measured is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample to be measured, wherein the easily diffusing element is an element outside the core functional layer of the thin-film solar cell and capable of migrating to cause a decrease in the battery efficiency.

[0009] In some optional real-time manners, the attenuation degree of the battery sample to be measured is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample to be measured, including:

[0010] The spectrum in which the characteristic spectral line of the characteristic element of the core functional layer first appears is found from the collected spectrum of the battery sample to be measured, and the corresponding pulse number is recorded, which is denoted as a node pulse number, and the spectrum corresponding to the node pulse number is denoted as a node spectrum;

[0011] According to the node spectrum of the battery sample to be measured, the ratio of the characteristic spectral line intensity of the easily diffusing element to the characteristic spectral line intensity of the characteristic element of the core functional layer is calculated, which is denoted as a first ratio;

[0012] The attenuation degree of the battery to be measured is evaluated based on the first ratio.

[0013] In some optional real-time manners, according to the node spectrum of the battery sample to be measured, the ratio of the characteristic spectral line intensity of the easily diffusing element to the characteristic spectral line intensity of the characteristic element of the core functional layer is calculated, which is denoted as a first ratio, including:

[0014] For a plurality of node spectra corresponding to a plurality of testing points on the surface of a plurality of battery samples to be measured, the node spectra are averaged to obtain an average intensity of the easily diffusing element and an average intensity of the characteristic element of the core functional layer, respectively;

[0015] The ratio of the average intensity of the easily diffusing element to the average intensity of the characteristic element of the core functional layer is calculated, which is denoted as a first ratio.

[0016] In some optional real-time manners, the attenuation degree of the battery to be measured is evaluated based on the first ratio, including:

[0017] The first ratio is divided by a second ratio to obtain an attenuation degree, wherein the second ratio is a ratio calculated by the same method as that for calculating the first ratio after the battery to be measured is replaced by a standard battery sample, wherein the battery sample to be measured and the standard battery sample are thin-film solar cells of the same batch and prepared by the same process and formula, the battery sample to be measured is subjected to normal use or placement, and the standard battery sample is stored in a light-proof manner in an environment conducive to the stability of the battery;

[0018] The attenuation degree of the battery to be measured is evaluated based on the attenuation degree, wherein the greater the attenuation degree, the more serious the performance degradation of the battery caused by element diffusion.

[0019] In some optional real-time manners, the degree of attenuation of the battery under test is evaluated based on the first ratio, including:

[0020] A plurality of first ratios of the battery sample under test are obtained, a plurality of second ratios of a standard battery sample are obtained, a statistical analysis is performed on the series of first ratios and second ratios, a numerical difference between the two groups of ratios is evaluated, and the attenuation of the battery sample under test is evaluated according to the numerical difference, wherein the battery sample under test and the standard battery sample are thin-film solar cells of the same batch and prepared by the same process and formula, the battery sample under test is used normally or placed, and the standard battery sample is stored in a light-proof environment to stabilize the battery.

[0021] In some optional real-time manners, the degree of attenuation of the battery under test is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample under test, including:

[0022] The target spectrum when the characteristic spectral line intensity of the easily diffusing element disappears is obtained, wherein when the characteristic spectral line intensity is less than the preset intensity for the first time as the number of laser pulses increases, it is considered that the corresponding element disappears;

[0023] Whether the performance of the battery under test is attenuated is evaluated based on whether the characteristic spectral line of the characteristic element of the core functional layer appears in the target spectrum, wherein when the characteristic spectral line intensity is greater than or equal to the preset intensity for the first time as the number of laser pulses increases, it is considered that the corresponding element appears.

[0024] In some optional real-time manners, the degree of attenuation of the battery under test is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample under test, including:

[0025] The spectrum of the standard battery sample is obtained in the same way as the spectrum of the battery sample under test, the number of pulses at which the easily diffusing element disappears for the first time is determined based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the standard battery sample, and is recorded as the first node pulse number, when the characteristic spectral line intensity is less than the preset intensity for the first time as the number of laser pulses increases, it is considered that the corresponding element disappears; the number of pulses at which the easily diffusing element disappears for the first time is determined based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample under test, and is recorded as the second node pulse number;

[0026] The degree of attenuation of the battery sample under test is evaluated based on the first node pulse number and the second node pulse number.

[0027] In a second aspect, the application provides a device for evaluating the degree of attenuation of a thin-film solar cell, including:

[0028] The laser pulse control module is used for controlling the laser output unit to continuously emit laser pulses, and the laser pulses are transmitted to a test point on the surface of the battery sample to be tested, so as to ablate and excite the battery sample layer by layer, generate plasma, collect the plasma radiation generated by the battery to be tested, and transmit the plasma radiation to a spectrometer to obtain the spectrum of the battery sample to be tested at different depths of the current test point, wherein the thickness direction of the battery is parallel to the stacking direction of the plurality of functional layers in the battery sample to be tested (i.e., perpendicular to the interface direction of each functional layer).

[0029] The repeated collection module is used for controlling the sample stage to move the battery sample to be tested to a next test point, and emitting the same number of laser pulses again, so as to repeat the above steps until the spectrum collection of all test points is completed.

[0030] The attenuation evaluation module is used for evaluating the attenuation degree of the battery sample to be tested based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample to be tested, wherein the easily diffusing element is an element outside the core functional layer of the thin-film solar cell and is prone to migration to cause a decrease in the battery efficiency.

[0031] In a third aspect, the present application provides a computer device, comprising a memory and a processor, the memory and the processor are communicatively connected with each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the method for evaluating the attenuation degree of the thin-film solar cell according to the first aspect or any one of the corresponding embodiments thereof.

[0032] In a fourth aspect, the present application provides a system for evaluating the attenuation degree of the thin-film solar cell, comprising:

[0033] A pulse laser is used for outputting laser pulses; a sample stage is used for placing the battery sample to be tested and moving the battery sample; a spectrometer is used for dispersing the plasma radiation generated by the laser ablation of the battery sample into wavelength-discrete spectrum, so as to obtain the spectrum of the battery sample at different depths of the current test point; and a computer device is connected with the pulse laser and the spectrometer respectively, and is used for executing the method for evaluating the attenuation degree of the thin-film solar cell according to the first aspect or any one of the corresponding embodiments thereof.

[0034] The present application has the following beneficial effects:

[0035] The method for evaluating the attenuation degree of a thin-film solar cell of the present application can continuously emit laser pulses to a test point on the surface of the cell to be measured, move to the next test point, continuously emit laser pulses to several test points, collect the plasma radiation generated by the cell to be measured, transmit the plasma radiation to a spectrometer, and obtain the spectrum of the sample of the cell to be measured at different depths of the current test point. The diffusion degree of the easily diffusing element in the cell to be measured can be analyzed based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the cell to be measured, and then the attenuation degree of the cell is evaluated. The present application ingeniously relates the element diffusion at the microscopic level to the performance attenuation of the cell at the macroscopic level based on the laser-induced breakdown spectroscopy technology, and opens up a way to quantitatively evaluate the attenuation degree of the thin-film solar cell from the perspective of element diffusion. Compared with the traditional method, the present application can better reflect the attenuation of the cell from the mechanism level. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0037] Figure 1 is a flowchart of the method for evaluating the attenuation degree of a thin-film solar cell according to an embodiment of the present application;

[0038] Figure 2 is a structural schematic diagram of a perovskite thin-film solar cell according to an embodiment of the present application;

[0039] Figure 3 is a structural schematic diagram of a system for evaluating the attenuation degree of a thin-film solar cell according to an embodiment of the present application;

[0040] Figure 4 is a spectrum diagram of a cell to be measured corresponding to the first laser pulse according to an embodiment of the present application;

[0041] Figure 5 is a spectrum diagram of a cell to be measured corresponding to the fifth laser pulse according to an embodiment of the present application;

[0042] Figure 6 is a spectrum diagram of a cell to be measured corresponding to the sixth laser pulse according to an embodiment of the present application;

[0043] Figure 7 is a spectrum diagram of a cell to be measured corresponding to the seventh laser pulse according to an embodiment of the present application;

[0044] Figure 8 is a spectrum diagram of a cell to be measured corresponding to the eighth laser pulse according to an embodiment of the present application;

[0045] Figure 9 is a spectrum diagram corresponding to the 9th laser pulse of the battery to be measured in the embodiment of the present application;

[0046] Figure 10 is a diagram showing the change of the intensity of Ag spectral line and Pb spectral line with the number of laser pulses in the battery to be measured in the embodiment of the present application;

[0047] Figure 11 is a diagram showing the change of the intensity of Ag spectral line and Pb spectral line with the number of laser pulses in the standard battery in the embodiment of the present application;

[0048] Figure 12 is a structural block diagram of the device for evaluating the attenuation degree of the thin-film solar cell in the embodiment of the present application;

[0049] Figure 13 is a hardware structural diagram of the computer device in the embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0051] According to the embodiments of the present application, a method embodiment for evaluating the attenuation degree of the thin-film solar cell is provided. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0052] In the present embodiment, a method for evaluating the attenuation degree of the thin-film solar cell is provided, which can be used in a computer device, in combination with Figure 1 and Figure 2 as shown, the flow includes the following steps:

[0053] In step S101, the pulsed laser is controlled to emit laser pulses continuously, the laser pulses are transmitted to a test point on the surface of the battery sample to be measured, the battery sample to be measured containing different functional layers is ablated and excited layer by layer to generate plasma, the plasma radiation generated by the battery to be measured is collected and transmitted to a spectrometer to obtain the spectrum of the battery sample to be measured at different depths along the thickness direction of the battery at the current test point, wherein the thickness direction of the battery is parallel to the stacking direction of the several functional layers in the battery sample to be measured (i.e. perpendicular to the direction of the interface of each functional layer).

[0054] The battery sample to be measured is a battery sample randomly selected from a batch of thin-film solar cells. The thin-film solar cells are composed of a plurality of functional layers stacked in sequence. In an ideal thin-film solar cell, the internal composition of each layer is uniform and stable, the same element is uniformly distributed in the same layer, and different layers do not diffuse into each other. The thin-film solar cell can be a perovskite thin-film solar cell, a silicon-based thin-film solar cell, a copper-indium-gallium-selenium thin-film solar cell, a cadmium telluride thin-film solar cell, or the like.

[0055] The battery sample to be measured is placed on the sample stage, and the incident direction of the laser pulse is parallel to the stacking direction of the functional layers. For example, when the battery sample to be measured is placed horizontally, the functional layers are stacked in the vertical direction, and the laser is incident perpendicular to the surface of the sample. Therefore, the incident direction of the laser pulse and the thickness direction of the laser ablation are both vertical directions. With continuous pulse emission, the laser can be focused on different functional layers of the battery sample to be measured.

[0056] For a batch of newly prepared thin-film solar cells, a piece of battery sample is taken out and placed for a period of time, or used for a long time or aged, and the battery sample is used as the battery sample to be measured.

[0057] The pulsed laser is used to output laser pulses. The laser pulses are continuously output at a certain frequency and focused near the surface of the battery to be measured to generate plasma. The plasma radiation is collected and transmitted to the spectrometer through an optical fiber to form a spectrum.

[0058] In an example, the wavelength of the laser pulse is 1064 nm, the pulse width is 10 ns, the energy is 10 mJ, and the laser frequency is 1 Hz. The number of test points can be 2, 3, 5, or 10, etc. The test points are uniformly arranged at different positions on the surface of the battery to be measured. By setting multiple test points, accidental errors at a single test point can be avoided to ensure the accuracy of the results.

[0059] In step S102, the sample stage moves the battery sample to be measured to the next test point, and the same number of laser pulses are emitted again. The above steps are repeated until the spectrum collection of all test points is completed.

[0060] Specifically, in the steps S101 and S102, based on the laser-induced breakdown spectroscopy (LIBS) technology, the laser ablation excitation is used to obtain the spectrum of the sample at different depths from the sample surface. The LIBS technology is a method for analyzing the composition and concentration of a substance based on the emission spectrum generated by the interaction of laser and the substance. The process and principle are as follows: the emitted laser pulse is focused on the surface of the sample to be tested, the sample is ablated to generate plasma, the plasma radiation is collected by a lens and then transmitted to a spectrometer by an optical fiber, and the spectrum is dispersed into a series of wavelength discrete spectra. The analysis of the spectrum can obtain the elemental composition and content of the sample. This technology does not require sample preparation, can be micro-damaged (the ablation mass of a single pulse is in the nanogram level), fast, and in-situ multi-element simultaneous analysis. The sample to be tested can be solid, liquid or gaseous, and almost all elements will emit characteristic spectral lines after being excited to form plasma, so LIBS can analyze most elements.

[0061] It should be understood that after each laser pulse is emitted, the material at the test point of the sample to be tested is ablated to expose the next layer of material. By continuously emitting laser pulses at the same test point and collecting the spectrum, the quantitative distribution of different elements along the thickness direction of the battery (i.e., the functional layer stacking direction) can be obtained. According to the actual size of the sample to be tested, the laser energy is optimized to control the ablation depth of a single pulse. Generally, the ablation depth of a single laser pulse on the sample to be tested is between 10 nm and 100 nm, which can effectively remove the surface layer material of the battery, so that the characteristic spectral lines of the characteristic elements of the core functional layer can be quickly revealed to realize the element distribution analysis along the functional layer stacking direction. Moreover, it will not cause insufficient spatial resolution accuracy due to too fast ablation, thereby resulting in inaccurate test results.

[0062] In step S103, the degree of attenuation of the sample to be tested is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the sample to be tested. The easily diffusing element is an element outside the core functional layer of the thin-film solar cell and can migrate to cause a decrease in the efficiency of the battery.

[0063] The core functional layer of the thin-film solar cell refers to a functional layer in the thin-film solar cell that undergoes photoelectric conversion or has a greater impact on the conversion efficiency. The easily diffusing element is an element in the thin-film solar cell that can migrate under the action of external forces such as light and high temperature to cause a decrease in the efficiency of the battery. The core functional layer and the easily diffusing element can be selected according to the actual situation and the focus of measurement during use. For example, for a perovskite battery, Ag in the silver electrode layer is easy to diffuse to the perovskite layer, so the core functional layer is selected as the perovskite layer (its chemical structure is ABX3: where A ion usually refers to monovalent cation, commonly MA+, FA+ and Cs+; B ion refers to divalent metal cation, commonly Pb2+ and Sn 2+ ; X ion is a halogen anion, such as I - 、Cl - and Br - . For example, ABX3 can be FAxMAyCs(1-xy)PbzSn(1-z)(ImClnBr(1-mn))3, wherein x, y, z, m, and n are the stoichiometric ratios of the components, all greater than or equal to 0 and less than or equal to 1. A method for evaluating the attenuation degree of a thin-film solar cell according to an embodiment of the present invention guides a laser beam through a lens and focuses it on a test point on the surface of the sample, emits a laser pulse to ablate the battery sample to be tested to generate plasma, collects the plasma radiation and transmits it to a spectrometer to obtain a spectrum. The laser is controlled to continuously emit several laser pulses to obtain the spectrum of the battery sample to be tested at different depths of the current test point. Afterwards, the sample is moved to the next test point, and the above operation is repeated until all test points are collected. Based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum, the quantitative distribution and diffusion degree of the easily diffusible elements along the stacking direction of different functional layers of the battery to be tested (i.e., the direction perpendicular to the interface of each functional layer) are obtained, and then the attenuation degree of the battery is evaluated. Based on laser-induced breakdown spectroscopy, the present invention correlates the element diffusion at the microscopic level with the macroscopic battery performance attenuation. The method of quantitatively evaluating the attenuation degree of thin-film solar cells from the perspective of element diffusion can better reflect the battery attenuation at the mechanism level compared with traditional methods.

[0064] In some embodiments, step S103, based on the intensity of characteristic spectral lines of easily diffusible elements in the spectrum of the battery sample to be tested, assessing the attenuation degree of the battery sample to be tested includes:

[0065] Step S1031, finding the spectrum where the characteristic line of the characteristic element of the core functional layer first appears from the collected spectrum of the battery sample to be tested, recording the corresponding pulse number, which is recorded as the node pulse number, and recording the spectrum corresponding to the node pulse number as the node spectrum;

[0066] Step S1032, calculating the ratio of the characteristic line intensity of the easily diffusible element to the characteristic line intensity of the core functional layer characteristic element based on the node spectrum of the battery sample to be tested, and recording it as a first ratio;

[0067] Step S1033 : Evaluate the attenuation degree of the battery to be tested based on the first ratio.

[0068] The core functional layer characteristic element is an element of the core functional layer of the battery to be tested, the easily diffusing element is an element that can diffuse to the core functional layer from other layers of the battery to be tested and affect the performance of the battery, and the easily diffusing element and the core functional layer characteristic element are related to the type of the thin-film solar cell. When the laser pulse is continuously focused and ablated on the surface layer of the battery to be tested, the core functional layer characteristic element is reached after ablation to a certain depth, so that the characteristic spectrum of the core functional layer characteristic element appears in the spectrum. As shown in FIG. 2, Figure 2 the easily diffusing element of the perovskite thin-film solar cell is the silver (Ag) layer on the surface, the core functional layer is the perovskite (ABX3) layer, and the characteristic element of the core functional layer is lead (Pb). The thickness of the Ag layer is about 100 nm, and the distance between the Ag layer and the ABX3 layer is about 40 nm. When the laser pulse is ablated to a thickness of about 140 nm, the ABX3 layer is ablated, and thus the characteristic spectrum of the core functional layer characteristic element can be detected.

[0069] Specifically, the first ratio is calculated as follows:

[0070] For a plurality of test points on the surface of the battery sample to be tested, the average intensity of the easily diffusing element and the average intensity of the core functional layer characteristic element are obtained by averaging the node spectrum intensity corresponding to each test point; and the ratio of the average intensity of the easily diffusing element to the average intensity of the core functional layer characteristic element is calculated, which is denoted as the first ratio. Alternatively, for each test point, the ratio of the intensity of the easily diffusing element characteristic spectrum to the intensity of the core functional layer characteristic spectrum is calculated, and then the intensity ratios of the various test points are averaged to obtain the first ratio.

[0071] For example, the number of test points is selected as M, M = 5, and 15 pulses are continuously emitted at each test point. For the Mth test point (m = 1, 2,..., M), the first n m pulses are ablated on the surface layer of the battery to be tested, and the spectrum of the core functional layer characteristic element appears in the n m th spectrum, i.e., the node pulse number n m is an integer and 1 < n m < 15, and the intensities of the characteristic spectrum of the easily diffusing element and the characteristic spectrum of the core functional layer characteristic element in the n m th spectrum (i.e., the node spectrum) are I and I , respectively. In this way, a series of characteristic spectrum intensities of the easily diffusing element at all test points are I , and the characteristic spectrum intensities of the core functional layer characteristic element are I , where n1, n2,..., n M are the node pulse numbers corresponding to the first to Mth test points. The average intensity of the characteristic spectrum of the easily diffusing element is I , and the average intensity of the characteristic spectrum of the core functional layer characteristic element is I The first ratio is Alternatively, according to the node spectrum of the mth test point, the spectral intensity ratio of the mth test point is obtained as The intensity ratios of the various test points are averaged to obtain the first ratio of the battery under test as

[0072] In some embodiments, step S1033, based on the first ratio, the attenuation degree of the battery under test is evaluated, including:

[0073] Step a1, the first ratio is divided by the second ratio to obtain the attenuation degree, wherein the second ratio is obtained by replacing the battery under test with a standard battery sample, and using the same method as the first ratio to calculate, wherein the battery under test sample and the standard battery sample are thin film solar cells of the same batch prepared by the same process and formula, the battery under test sample is used normally or placed, and the standard battery sample is stored in a light-proof environment to stabilize the battery. It can be considered that the standard battery sample has a lower degree of attenuation. The standard battery sample can be selected from several to reduce the accidental error caused by the abnormal situation of individual standard sample;

[0074] Step a2, based on the attenuation degree, the attenuation degree of the battery under test is evaluated, wherein the greater the attenuation degree, the more serious the performance degradation of the battery due to element diffusion.

[0075] Specifically, the standard battery sample is a thin film solar cell newly prepared in the same batch as the battery under test sample. For the thin film solar cells prepared in the same batch, one battery is extracted for normal use or placement as the battery under test sample F1; a plurality of batteries are randomly extracted for light-proof storage, which are considered to have a lower degree of attenuation and aging, and are used as standard battery samples F2. For the battery under test sample F1 and the standard battery sample F2, the first and second ratios obtained by using the same calculation method are respectively and

[0076] The attenuation degree is defined as R≥1. The attenuation degree R is calculated and output.

[0077] By taking the standard battery with a lower degree of attenuation as a reference, the user can quickly and intuitively understand the actual attenuation condition of the battery under test, which has practical value in the state evaluation in practical application.

[0078] In some embodiments, step S1033, based on the first ratio, the attenuation degree of the battery under test is evaluated, including:

[0079] Step b1, obtaining a plurality of first ratios of the battery sample to be tested, obtaining a plurality of second ratios of the standard battery sample, performing statistical analysis on the series of first ratios and second ratios, evaluating the numerical difference between the two groups of ratios, and evaluating the degradation of the battery sample to be tested according to the numerical difference, wherein the battery sample to be tested and the standard battery sample are thin-film solar cells of the same batch prepared by the same process and formula, the battery sample to be tested is subjected to normal use or placement, and the standard battery sample is stored in a light-proof environment in a stable environment.

[0080] According to the node spectrum of all test points of the battery sample to be tested and all test points of the standard battery sample, a series of ratios of the characteristic spectrum line intensity of the easily diffusing element to the characteristic spectrum line intensity of the core functional layer characteristic element is obtained. Statistical analysis is performed on the series of ratios of the battery to be tested and the standard battery, and it is judged whether the two groups of values have overall differences.

[0081] Exemplarily, variance analysis is performed on the two groups of ratios: for the battery to be tested F1 and the standard battery F2, there are first ratio sequences and second ratio sequences Wherein is the ratio of the characteristic spectrum line intensity of the easily diffusing element to the characteristic spectrum line intensity of the core functional layer characteristic element corresponding to the node spectrum of the mth test point of the battery to be tested. m=1,2,……,M, M is the number of test points on the surface of the battery sample to be tested or the standard battery sample. The following is the variance analysis of the two groups of ratios:

[0082] The average of all ratios, i.e. the total mean, is calculated, denoted as

[0083]

[0084] The total variation of the two groups of ratios, i.e. the square sum of the difference between each ratio and the average is calculated, denoted as SS 总 :

[0085]

[0086] The inter-group variation of the two groups of ratios, i.e. the square sum of the deviation from the mean of the two groups of ratios and the total mean, is calculated, denoted as:

[0087]

[0088] Wherein, is the intra-group mean of the two groups of ratios, F is F1 or F2.

[0089] The intra-group variation of all ratios, i.e. the square sum of the difference between all ratios and the mean of the group The sum of squares of the deviations from the mean (F is F1 or F2) is recorded as:

[0090]

[0091] It can be proved that:

[0092] SS 总 =SS 组间 +SS 组内

[0093] The degrees of freedom for total variation, between-group variation, and within-group variation are:

[0094] f 总 =2M-1,f 组间 =g-1,f 组内 =2M-g

[0095] Wherein, g is the number of data groups, here g = 2.

[0096] Divide the between-group variation and within-group variation by their respective degrees of freedom to obtain the between-group mean square error and the within-group mean square error: The ratio of the mean square error between groups to the mean square error within groups is called the F statistic, that is, F = MS 组间 / MS 组内 The null hypothesis is that there is no significant difference between the two groups. Combined with the preset significance α, the F distribution table is searched to obtain F α (f 组间 , f 组内 ). If the calculated F>F α , the original hypothesis is rejected and it is considered that there is a significant difference between the two groups of ratios. That is, the performance of the battery under test has degraded compared to the standard battery sample.

[0097] In some embodiments, step S103, based on the intensity of characteristic spectral lines of easily diffusible elements in the spectrum of the battery sample to be tested, assessing the attenuation degree of the battery sample to be tested includes:

[0098] Step S1034 , obtaining the target spectrum when the characteristic line intensity of the easily diffusible element disappears, wherein when the characteristic line intensity first reaches a peak as the number of laser pulses increases and then becomes less than a preset intensity for the first time, it is considered that the corresponding element disappears.

[0099] Step S1035, based on whether the target spectrum shows the characteristic line of the core functional layer characteristic element, the performance of the battery to be tested is evaluated to see whether it has decayed. When the intensity of the characteristic line increases with the number of laser pulses and is greater than or equal to the preset intensity for the first time, it is considered that the corresponding element has appeared. Specifically, the preset intensity I Δ A custom intensity, such as I Δ =3σ, σ is the standard deviation of the spectral background intensity. When the spectral line intensity of the easily diffusible element first drops to the preset intensity IΔ When the easily diffusible element disappears, it is judged whether the spectrum of the current diffusion depth has the core functional layer characteristic element, that is, whether the spectral line intensity of the core functional layer characteristic element is greater than I Δ If the spectrum of the current diffusion depth shows characteristic spectral lines of characteristic elements of the core functional layer, it is determined that the performance of the battery under test has degraded.

[0100] In some embodiments, step S103, based on the intensity of characteristic spectral lines of easily diffusible elements in the spectrum of the battery sample to be tested, assessing the attenuation degree of the battery sample to be tested includes:

[0101] In step S1036, a spectrum of a standard battery sample is obtained in the same manner as the spectrum of the battery sample to be tested. Based on the intensity of the characteristic spectral line of the easily diffusible element in the spectrum of the standard battery sample, the number of pulses at which the easily diffusible element first disappears is determined, recorded as the first node pulse number P1. When the intensity of the characteristic spectral line increases with the number of laser pulses and first falls below a preset intensity, the corresponding element is considered to have disappeared.

[0102] Step S1037 : Based on the characteristic line intensity of the easily diffusible element in the spectrum of the battery sample to be tested, the number of pulses at which the easily diffusible element disappears for the first time is determined, and recorded as the second node pulse number P2 .

[0103] Step S1038: Evaluate the attenuation of the battery sample based on the first node pulse number P1 and the node pulse number P2. The attenuation R can be defined as: R = (P2-P1) / P1×100%.

[0104] The method for evaluating the degradation degree of thin-film solar cells according to an embodiment of the present invention will be described below with reference to a specific application.

[0105] This embodiment takes the perovskite thin film solar cell as an example, using a laser pulse with a wavelength of 1064nm, a pulse width of 10ns, and an energy of 10mJ. The breakdown depth of one pulse is about 25nm. The structure of the perovskite thin film solar cell is as follows: Figure 1 , from top to bottom are the Ag layer, the main element is Ag; BCP layer, the main elements are carbon (C), hydrogen (H) and nitrogen (N); C 60 The main elements of the ABX3 layer are C; the main elements of the ABX3 layer are lead (Pb), iodine (I), C, H, and N; the main elements of the PEACl layer are C, H, N, and chlorine (Cl); the main elements of the MeO-2PACZ layer are C, H, N, and oxygen (O); and the main elements of the ITO layer are indium (In), tin (Sn), and O. Ag intrusion into the ABX3 layer is a common cause of perovskite cell failure, so the change in the spectral intensity corresponding to the Ag element with depth is observed to assess the degree of cell aging.

[0106] After preparing the perovskite thin film solar cell sample, the specific implementation steps are as follows:

[0107] Two perovskite thin film solar cells were randomly selected from the same batch of perovskite thin film solar cells, one of which was subjected to accelerated aging treatment as the test cell sample F1, and the other was stored in the dark and was considered to be approximately not attenuated in the subsequent test as the standard cell sample F2.

[0108] (2) A laser pulse generator with a wavelength of 1064 nm and a pulse width of 10 ns was used to emit laser pulses, and the laser frequency was set to 1 Hz. The laser pulse was focused on the surface of the solar thin film solar cell sample, and the optimal laser energy was 10 mJ and the focused spot size was 200 μm, so that the ablation depth of a single laser pulse was about 25 nm. Laser pulse ablation excited the sample surface material to generate plasma, and the plasma radiation was guided to the entrance of the spectrometer through a plano-convex lens and an optical fiber in turn. The plasma radiation was dispersed by the spectrometer to obtain laser-induced breakdown spectroscopy, which was displayed on the computer software interface. The delay time for spectrometer acquisition was set to 500 ns, and the gate width was 1 ms.

[0109] (3) The test cell sample F1 and the standard cell sample F2 were used as samples respectively, and laser pulses were emitted on the surface of the samples at five positions A1, A2, A3, A4, and A5. Ten pulses were emitted continuously at each position to obtain the original spectral data sequence where X = A1, A2, A3, A4, A5; j = 1, …, 10. The average spectra corresponding to different sample surface positions and the same number of pulses were obtained by averaging where j = 1, …, 10. In this way, for the test cell sample F1 and the standard cell sample F2, 10 average spectra corresponding to pulse numbers 1 to 10 were obtained respectively and

[0110] (4) The average spectra corresponding to pulse numbers 1, 5, 6, 7, 8, and 9 of the test cell sample F1, i.e. as shown in Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 .

[0111] For the first pulse, the laser pulse was focused on the silver electrode layer on the surface of the cell sample, and the spectral peaks appeared were all Ag element spectral lines, Figure 4 where the representative spectral line Ag(I) 328.07 nm is marked. For the fifth pulse, the laser pulse was focused on the BCP layer and penetrated to the C 60 layer. Since Ag elements diffuse to this layer, the spectral peaks appearing contain Ag, C, H, and N spectral lines,Figure 5 The representative spectral lines are Ag(I) 328.07 nm and C(I) 247.86 nm. For the 6th to 8th pulses, the laser pulse focuses on the ABX3 layer, and the spectrum contains Ag, Pb, I, C, H, N spectral lines due to the diffusion of Ag element, Figure 6 The representative spectral lines are Ag(I) 328.07 nm and Pb(I) 405.78 nm. At the 9th pulse, the Ag spectral line completely disappears, and only the spectral lines of the ABX3 layer elements themselves remain. The Pb element appears at the 6th pulse, indicating that the 6th pulse focuses on the perovskite layer, and the intensity of Ag(I) 328.07 nm is still as high as 1.40 x 10 8 (which is much larger than 3 times the standard deviation of the background intensity), indicating that the Ag element has diffused into the ABX3 layer, which may affect the performance of the battery.

[0112] The intensity of Ag(I) 328.07 nm and Pb(I) 405.78 nm in the test battery F1 changes with the number of pulses as shown in Figure 10 At the 6th pulse, the ratio of the intensity of Ag(I) 328.07 nm to the intensity of Pb(I) 405.78 nm is The intensity of Ag(I) 328.07 nm and Pb(I) 405.78 nm in the standard battery sample F2 changes with the number of laser pulses as shown in Figure 11 It can be found that the intensity of Ag(I) 328.07 nm decreases rapidly after the 1st pulse; the intensity of Pb(I) 405.78 nm increases rapidly at the 6th pulse, indicating that the 6th pulse focuses on the perovskite layer, and the intensity of Ag(I) 328.07 nm is less than 3 times the standard deviation of the background intensity (about 1 x 10 4 ), and it is considered that Ag(I) 328.07 nm is approximately disappeared. The ratio of the intensity of Ag(I) 328.07 nm to the intensity of Pb(I) 405.78 nm at the 6th pulse of the standard battery sample F2 is

[0113] (5) For the test battery sample F1 and the standard battery sample F2, G F1 and G F2 are compared, and the attenuation degree of the test battery sample F1 is R = G F1 / G F2 = 1.417 / 0.047 = 30.14. The degree of degradation of the battery sample is quantitatively characterized.

[0114] On the other hand, the embodiment of the present application also provides a system for evaluating the attenuation degree of a thin-film solar cell, as shown in Figure 3As shown, the system comprises: a pulsed laser 1 for outputting laser pulses; a sample stage for placing and moving a battery sample to be tested; a spectrometer 9 for dispersing plasma radiation generated by laser ablation of the battery sample to be tested into wavelength-discrete spectra; a computer device 10 connected with the spectrometer 9 for executing the method for evaluating the attenuation degree of a thin-film solar cell in any of the above embodiments. The triggering of the pulsed laser 1 and the spectrometer 9 is synchronously controlled by a digital delay generator 12 to ensure accurate timing of laser emission and plasma radiation collection.

[0115] The laser pulses emitted by the pulsed laser are sequentially guided through the first mirror 2, the second mirror 3 and the third mirror 4, and then focused by the first plano-convex lens 5 to irradiate the battery sample 6 on the sample stage, which can be a battery sample to be tested or a standard battery sample. The battery sample 6 is placed on the sample stage, and the sample stage is moved so that the laser irradiates different test point positions on the surface of the battery sample 6. The material on the surface of the battery sample 6 is vaporized and partially ionized by heat to form a high-temperature plasma 11 composed of atoms, ions and electrons, which continuously emits radiation during its lifetime. The plasma radiation is collected by the second plano-convex lens 7, transmitted to the spectrometer 9 through the optical fiber 8, and dispersed into wavelength-discrete spectra by the spectrometer. The spectra contain information about the element composition at the test point, and the information about the element types and contents of the sample material is displayed in the relevant software of the computer device 10. The spectra are analyzed by the computer device 10.

[0116] The embodiment of the present application also provides a device for evaluating the attenuation degree of a thin-film solar cell, as shown in the accompanying drawings, comprising: Figure 12 As shown, comprising:

[0117] The laser pulse control module 201 is configured to control the pulsed laser to continuously emit laser pulses, and the laser pulses are transmitted to test points on the surface of the battery sample to be tested, so as to perform layer-by-layer ablation and excitation on the battery sample to be tested containing different functional layers, generate plasma, collect the plasma radiation generated by the battery sample to be tested, transmit the plasma radiation to the spectrometer, and obtain the spectra of the battery sample to be tested at different depths along the thickness direction of the battery at the current test point, wherein the thickness direction of the battery is parallel to the stacking direction of the plurality of functional layers in the battery sample to be tested, i.e., perpendicular to the direction of the interfaces of the functional layers.

[0118] The repeated collection module 202 is configured to control the sample stage to move the battery sample to be tested to the next test point, emit the same number of laser pulses again, and repeat the above steps until the spectra collection of all test points is completed.

[0119] The attenuation evaluation module 203 is configured to evaluate the attenuation degree of the battery sample based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery sample, wherein the easily diffusing element is an element outside the core functional layer of the thin-film solar cell and capable of migrating to cause the efficiency of the battery to decrease.

[0120] The device for evaluating the attenuation degree of the thin-film solar cell according to the application continuously emits laser pulses to the same position on the surface of the battery sample to be tested, performs layer-by-layer ablation and excitation on the sample, and obtains the spectrum at different depths of the sample, which contains the element type and concentration information of the battery to be tested. The attenuation degree of the battery to be tested is evaluated based on the characteristic spectral line intensity of the easily diffusing element in the spectrum of the battery to be tested. The application links the element diffusion at the microscopic level to the performance attenuation of the battery at the macroscopic level based on laser-induced breakdown spectroscopy, and opens up a way to quantitatively evaluate the attenuation degree of the thin-film solar cell from the perspective of element diffusion, which can reflect the attenuation of the battery from the mechanism level compared with the traditional method.

[0121] The embodiment of the application further provides a computer device, as shown in the figure, the computer device comprises one or more processors 110, a memory 120, and an interface for connecting components, including a high-speed interface and a low-speed interface. Various components are communicatively connected to each other by different buses, and can be installed on a common mainboard or in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display GUI graphical information on an external input / output device, such as a display device coupled to the interface. In some optional embodiments, multiple processors and / or multiple buses can be used with multiple memories and multiple memories, if necessary. Similarly, multiple computer devices can be connected, each providing part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 13 The figure shows an example of a processor 110. Figure 13

[0122] The processor 110 can be a central processor, a network processor, or a combination thereof. The processor 110 can further include a hardware chip. The hardware chip can be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device can be a complex programmable logic device, a field programmable logic gate array, a general array logic, or any combination thereof.

[0123] The memory 120 stores instructions executable by the at least one processor 110, so that the at least one processor 110 executes the method shown in the above embodiments.

[0124] ​The memory 120 can include a program storage area and a data storage area. The program storage area can store an operating system, application programs required for at least one function, and the like. The data storage area can store data created according to the use of the computer device, and the like. In addition, the memory 120 can include a high-speed random access memory, and can further include a non-transitory memory such as at least one of a magnetic disk storage device, a flash memory device, or other non-transitory solid state storage device. In some alternative embodiments, the memory 120 can optionally include a memory disposed remotely from the processor 110, which can be connected to the computer device through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0125] The memory 120 can include a volatile memory such as a random access memory, and can further include a non-volatile memory such as a flash memory, a hard disk, or a solid state disk. The memory 120 can further include a combination of the above-mentioned types of memories.

[0126] The computer device further includes an input device 130 and an output device 140. The processor 110, the memory 120, the input device 130, and the output device 140 can be connected through a bus or other means, Figure 13 The connection through the bus is taken as an example.

[0127] The input device 130 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touchpad, a pointing stick, one or more mouse buttons, a trackball, a joystick, and the like. The output device 140 can include a display device, an auxiliary lighting device (e.g., an LED), a tactile feedback device (e.g., a vibration motor), and the like. The display device includes, but is not limited to, a liquid crystal display, a light emitting diode, a display, and a plasma display. In some alternative embodiments, the display device can be a touch screen.

[0128] Although embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be suggested to one skilled in the art, and it is intended that the appended scope of the present application encompass all such modifications and changes.

Claims

1. A method for evaluating the degradation degree of thin film solar cells, characterized in that: include: Controlling a pulsed laser to continuously emit laser pulses, which are transmitted to a test point on the surface of a battery sample to be tested, ablating and exciting the battery sample to be tested containing different functional layers layer by layer to generate plasma, collecting the plasma radiation generated by the battery to be tested, and transmitting it to a spectrometer to obtain spectra of the battery sample to be tested at different depths along the battery thickness direction at the current test point, wherein the battery thickness direction is parallel to the stacking direction of the functional layers in the battery sample to be tested; Control the sample stage to move the battery sample to the next test point, emit the same number of laser pulses again, and repeat the above steps until the spectrum acquisition of all test points is completed; The attenuation degree of the battery sample to be tested is evaluated based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum of the battery sample to be tested, wherein the easily diffusible elements are elements outside the core functional layer of the thin-film solar cell and can migrate and cause a decrease in battery efficiency.

2. The method for evaluating the attenuation degree of thin-film solar cells according to claim 1, characterized in that: Based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum of the battery sample to be tested, the attenuation degree of the battery sample to be tested is evaluated, including: Find the spectrum where the characteristic line of the characteristic element of the core functional layer first appears from the collected spectrum of the battery sample to be tested, record the corresponding pulse number, and record it as the node pulse number. The spectrum corresponding to the node pulse number is recorded as the node spectrum; According to the node spectrum of the battery sample to be tested, the ratio of the characteristic spectral line intensity of the easily diffusible element to the characteristic spectral line intensity of the core functional layer characteristic element is calculated, and recorded as the first ratio; The attenuation degree of the battery to be tested is evaluated based on the first ratio.

3. The method for evaluating the degradation degree of thin-film solar cells according to claim 2, characterized in that: According to the node spectrum of the battery sample to be tested, the ratio of the characteristic spectral line intensity of the easily diffusible element to the characteristic spectral line intensity of the core functional layer characteristic element is calculated, which is recorded as the first ratio, including: For several node spectra corresponding to the test points on the surface of several battery samples to be tested, the node spectra are averaged to obtain the average intensity of the easily diffusible elements and the average intensity of the characteristic elements of the core functional layer; The ratio of the average intensity of the easily diffusible elements to the average intensity of the characteristic elements of the core functional layer is calculated and recorded as the first ratio.

4. The method for evaluating the degradation degree of thin-film solar cells according to claim 3, characterized in that: The attenuation degree of the battery to be tested is evaluated based on the first ratio, including: Dividing the first ratio by the second ratio to obtain the attenuation degree, wherein the second ratio is a ratio calculated using the same method as the first ratio after replacing the battery to be tested with a standard battery sample, wherein the battery sample to be tested and the standard battery sample are thin-film solar cells produced from the same batch using the same process and formula, the battery sample to be tested has been subjected to normal use or storage, and the standard battery sample has been stored away from light in an environment conducive to battery stability; The attenuation degree of the battery to be tested is evaluated based on the attenuation degree, wherein a greater attenuation degree represents a more serious degradation of the battery performance due to element diffusion.

5. The method for evaluating the degradation degree of thin-film solar cells according to claim 3, characterized in that: The attenuation degree of the battery to be tested is evaluated based on the first ratio, including: A plurality of first ratios of the battery samples to be tested and a plurality of second ratios of the standard battery samples are obtained, a statistical analysis is performed on a series of the first ratios and the second ratios, the numerical difference between the two groups of ratios is evaluated, and the attenuation of the battery samples to be tested is evaluated based on the numerical difference, wherein the battery samples to be tested and the standard battery samples are thin-film solar cells prepared by the same process and formula from the same batch, the battery samples to be tested have been subjected to normal use or storage, and the standard battery samples have been stored away from light in an environment conducive to battery stability.

6. The method for evaluating the degradation degree of thin-film solar cells according to claim 1, characterized in that: Based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum of the battery sample to be tested, the attenuation degree of the battery sample to be tested is evaluated, including: Obtain the target spectrum when the characteristic line intensity of the easily diffusible element disappears, wherein when the characteristic line intensity first reaches a peak as the number of laser pulses increases and then becomes less than a preset intensity for the first time, the corresponding element is considered to have disappeared; Whether the performance of the battery under test has decayed is evaluated based on whether the characteristic spectral lines of the characteristic elements of the core functional layer appear in the target spectrum. When the intensity of the characteristic spectral line increases with the number of laser pulses and is greater than or equal to the preset intensity for the first time, it is considered that the corresponding element appears.

7. The method for evaluating the degradation degree of thin-film solar cells according to claim 1, characterized in that: Based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum of the battery sample to be tested, the attenuation degree of the battery sample to be tested is evaluated, including: The spectrum of the standard battery sample is obtained in the same manner as that of the battery sample to be tested. Based on the intensity of the characteristic spectral line of the easily diffusible element in the spectrum of the standard battery sample, the number of pulses at which the easily diffusible element disappears for the first time is determined, and recorded as the first node pulse number. When the intensity of the characteristic spectral line increases with the number of laser pulses and is less than the preset intensity for the first time, it is considered that the corresponding element disappears. Based on the intensity of the characteristic spectral line of the easily diffusible element in the spectrum of the battery sample to be tested, the number of pulses at which the easily diffusible element disappears for the first time is determined, and recorded as the second node pulse number. The attenuation degree of the battery sample to be tested is evaluated based on the first node pulse number and the second node pulse number.

8. A device for evaluating the degradation degree of thin-film solar cells, characterized in that: include: A laser pulse control module is used to control the pulsed laser to continuously emit laser pulses. The laser pulses are transmitted to the test point on the surface of the battery sample to be tested, and the battery sample to be tested containing different functional layers is ablated and excited layer by layer to generate plasma. The plasma radiation generated by the battery to be tested is collected and transmitted to the spectrometer to obtain the spectrum of the battery sample to be tested at different depths along the battery thickness direction at the current test point, wherein the battery thickness direction is parallel to the stacking direction of the multiple functional layers in the battery sample to be tested; The repeated acquisition module is used to control the sample stage to move the battery sample to the next test point, emit the same number of laser pulses again, and repeat the above steps until the spectrum acquisition of all test points is completed; The attenuation evaluation module is used to evaluate the attenuation degree of the battery sample to be tested based on the characteristic spectral line intensity of the easily diffusible elements in the spectrum of the battery sample to be tested, wherein the easily diffusible elements are elements outside the core functional layer of the thin-film solar cell and can migrate and cause the battery efficiency to decrease.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for evaluating the degree of degradation of a thin-film solar cell according to any one of claims 1 to 7 by executing the computer instructions.

10. A system for evaluating the degradation degree of thin-film solar cells, characterized in that: include: Pulsed laser, used to output laser pulses to ablate battery samples; The sample stage is used to place the battery sample and move the battery sample so that the laser beam can be focused on different test points on the sample surface; A spectrometer is used to disperse the plasma radiation generated by laser ablation of the battery sample into wavelength-discrete spectra, thereby obtaining spectra of the battery sample at different depths of the current test point; A computer device connected to the spectrometer, for executing the method for evaluating the degradation degree of a thin-film solar cell according to any one of claims 1 to 7.

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