Method for measuring P2 laser scribing introduced contact resistance in perovskite solar module

Abstract

The invention relates to a method for measuring contact resistance introduced by P2 laser scribing in a perovskite solar module, which can conveniently judge P2 scribing quality, and particularly, directly calculates the contact resistance introduced by P2 laser scribing by comparing resistance changes measured before and after P3 laser scribing. According to the method, the test process is simplified, the effects of different P2 parameters and the scribing effects of P2 with the same parameters on different positions can be compared on the same substrate at the same time, the experiment difficulty is greatly reduced, a reliable basis is provided for optimizing laser parameters, and the performance and reliability of the whole perovskite solar cell module are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and in particular relates to a method for measuring contact resistance introduced by P2 laser scribing in a perovskite solar module. Background Art

[0002] Laser scribing, a high-precision, non-contact processing technology, plays a crucial role in the fabrication and optimization of perovskite solar cell modules. By precisely controlling laser parameters (such as power, wavelength, and pulse width), micron-level patterning can be achieved. This technique not only ensures effective connectivity between subcells but also significantly improves the overall performance and stability of the module.

[0003] Especially in the P2 process, the role of laser scribing is particularly critical. The main purpose of P2 laser scribing is to connect the top electrode and the bottom electrode of adjacent sub-cells in series, thereby forming a complete current path. However, improper P2 laser scribing may cause a series of problems, such as excessive functional layer residue or severe damage to the bottom electrode, which will seriously affect the performance of the module. Specifically, it manifests as higher contact resistance, which usually leads to greater series resistance in IV testing, thereby reducing the fill factor and ultimately affecting the photoelectric conversion efficiency of the perovskite solar cell module.

[0004] Currently, evaluating P2 laser scribing performance is complex and time-consuming, often requiring sophisticated equipment and techniques, which presents a challenge for researchers. Furthermore, existing methods struggle to compare the effects of multiple P2 parameters simultaneously on the same substrate, complicating experimental design and data analysis.

[0005] Therefore, a simple and accurate method to measure the contact resistance generated by P2 laser scribing is urgently needed to quickly evaluate the effectiveness of laser parameters and provide a basis for subsequent process optimization. This method can not only help researchers better understand the various influencing factors in the laser scribing process, but also provide reliable technical support for large-scale production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention aims to provide a method for accurately measuring the contact resistance generated by P2 laser scribing in perovskite solar cell modules. This method allows for the evaluation and optimization of laser parameters, thereby improving the performance and reliability of the entire module. By comparing the resistance change before and after P3 scribing, the contact resistance introduced by P2 laser scribing can be directly assessed, which is crucial for optimizing laser parameters.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for measuring contact resistance introduced by P2 laser scribing in a perovskite solar module, the method comprising the following steps:

[0009] (1) Sample preparation: The perovskite device that has completed the P1 and P2 laser scribing processes is used as the measurement sample.

[0010] (2) Functional layer removal: Before evaporating the metal electrode, use laser to remove all functional layers on both sides of the laser-scribed area of ​​the sample to ensure that the metal electrode subsequently evaporated in the cleared area is in direct contact with the transparent conductive oxide layer TCO;

[0011] (3) Metal electrode evaporation: After completing the above functional layer removal step, a metal electrode is evaporated on the sample surface.

[0012] (4) Initial resistance measurement: Use a milliohm meter to measure the resistance on both sides of the laser-marked area and record the total resistance R t1 And mark the position of the milliohm meter pen contact.

[0013] (5) P3 scribing and secondary measurement: Perform the P3 laser scribing process so that the metal electrodes on both sides of the laser scribing area are only connected through the ohmic contact between the metal electrodes and the TCO at the P2 scribing location. After completing the above steps, use a high-precision milliohm meter to measure the resistance at the marked position and record the total resistance R t2 .

[0014] (6) Calculation of contact resistance: The contact resistance R caused by P2 laser scratching can be calculated by taking the difference between the resistance values ​​obtained from the two measurements. c .

[0015] Specifically, the milliohm meter in step (4) has an accuracy of 0.001Ω, which is used to measure the accuracy of contact resistance.

[0016] Furthermore, in step (6), multiple positions on the same substrate are selected for laser scribing, wherein the laser parameters for P2 scribing on the substrate are kept consistent, and the resistance at both ends of all laser-scribed areas is measured, and finally the difference is calculated to obtain the contact resistance R c The average value, specifically R c =(R t4 -R t3 ) / n, where R t3 is the resistance measured at both ends of P3 before scratching, where R t4 This is the resistance measured at both ends after P3 is scratched. This method reduces the measurement error caused by different contact positions.

[0017] Furthermore, in step (6), multiple positions on the same substrate are selected for laser scribing, wherein the laser parameters for P2 scribing on the substrate are different. By calculating the contact resistance corresponding to the P2 scribing with different laser parameters on the substrate, the P2 scribing effects with different laser parameters can be compared and the P2 laser parameters with the best scribing quality can be quickly screened out.

[0018] Specifically, during the measurement process, the ambient temperature was 20-25° C., the relative humidity was maintained between 20% and 60%, and the surface was kept clean.

[0019] Specifically, during the laser marking process, it is necessary to grasp the mark and position it to ensure the accuracy of the laser marking.

[0020] Specifically, a TCO conductive substrate with a square resistance of less than 20Ω / □ is selected for the conductive part resistance of the TCO layer below P3 to reduce the influence of the conductive part resistance of the TCO layer below P3.

[0021] The beneficial effects of the present invention are as follows:

[0022] Compared with the existing technology, the present invention provides a measurement method with a reasonable structure, simple operation and reliable results for evaluating the contact resistance at the P2 laser scribing site in perovskite solar cell modules. Through this method, not only can the evaluation process of the P2 laser scribing effect be significantly simplified, but also rapid feedback and optimization adjustment of process parameters can be achieved during scientific research and production, thereby improving R&D efficiency and process stability. In addition, this method helps to deeply analyze the key factors that lead to unqualified device performance or unstable operation, such as uneven laser energy distribution, inconsistent scribing depth or poor adhesion of the metal layer, providing strong support for improving laser processing technology and enhancing the overall performance of the device.

[0023] At the same time, the present invention overcomes the shortcomings of traditional evaluation methods, such as complex operations, long time consumption, and reliance on subjective judgment, and proposes a technical solution with strong repeatability, objective data, and applicability to standardized testing. While ensuring measurement accuracy, this method reduces experimental conditions and technical barriers, which is conducive to promotion and application on a larger scale. Therefore, the present invention not only has important guiding significance in the research and development and industrialization of perovskite solar cells, but also provides a feasible reference path for the process evaluation of other thin-film photovoltaic devices, with good application prospects and socioeconomic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of P2 laser and functional layer removal in the embodiment;

[0025] Figure 2 Schematic diagram of the initial resistance measurement in the embodiment;

[0026] Figure 3 This is a schematic diagram of the secondary resistance measurement in the embodiment;

[0027] Figure 4 Schematic diagram of measuring the contact resistance of multiple P2 laser scribing lines in the embodiment;

[0028] Figure 5 A graph comparing the primary resistance measurement results and secondary resistance measurement results of substrates processed by P2 laser scribing with different laser parameters in the embodiment;

[0029] Figure 6 This is a graph comparing the contact resistance results corresponding to different laser parameters in the example.

[0030] Figure numerals: 1-glass substrate; 2-transparent conductive oxide layer; 3-functional layer; 4-functional layer to be removed; 5-silver electrode, 6-laser scribing processing area, 7-first contact, 8-second contact, 9-third contact, 10-fourth contact, 11-fifth contact. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] Sample Preparation: A 5cm x 5cm glass substrate coated with a fluorine-doped tin oxide (FTO) layer was prepared and laser-scribed and marked with P1. The substrate was then ultrasonically cleaned in deionized water, acetone, and ethanol, dried with nitrogen, and then treated in a UV-ozone cleaner for 15 minutes. Following UV oxidation, a 1mg / mL self-assembled monolayer (SAM) solution was spin-coated onto the cleaned FTO conductive glass substrate at 5000 rpm for 30 seconds, followed by annealing at 100°C for 10 minutes. Next, a 1.4M perovskite solution was spin-coated onto the substrate at 1000 rpm for 10 seconds, followed by an additional 30 seconds at 5000 rpm. During the final 5 seconds of the spin-coating process, 600 μL of the antisolvent CB was added dropwise. After spin coating, the substrate was annealed at 100°C for 30 minutes. Next, 300 μL of a 2 mg / mL PEAI solution was dynamically spin-coated at 4000 rpm for 30 seconds. Next, a 20 mg / mL PCBM solution was spin-coated at 1500 rpm for 60 seconds. Finally, 300 μL of a 0.5 mg / mL BCP solution was dynamically spin-coated at 4500 rpm for 25 seconds.

[0033] P2 Scribing and clearing of functional layer: Figure 1As shown, P2 laser scribing is performed using positioning and grabbing, where the parameters of the P2 laser scribing are the parameters to be tested. Laser positioning and grabbing are then used to precisely remove the functional layer 4 to ensure that the subsequently deposited silver electrode 5 can fully contact the FTO in this area. This area of ​​the functional layer 3 is retained for subsequent P3 laser scribing.

[0034] Evaporation of silver electrode 5 and initial resistance measurement: Figure 2 As shown, a layer of 80nm silver electrode 5 is evaporated on the surface of the device, and then the resistance R is measured at the marked "contact 1" and "contact 2" respectively using the two test leads of the milliohm meter. t1 , which represents the resistance of the silver electrode between "Contact 1" and "Contact 2".

[0035] P3 scratching and secondary resistance measurement: Figure 3 As shown, laser marking P3 is performed by positioning the mark, so that the metal electrodes on both sides of the laser-marked area 6 are connected only through the P2 marking area, where the metal electrodes and the transparent conductive oxide layer 2 (Transparent Conductive Oxide, abbreviated as TCO) are in ohmic contact. The resistance R is then measured at the marked contact points 1 and 2 using the two probes of a milliohmmeter. t2 , which represents the sum of the resistance of the silver electrode 5 between "contact 1" and "contact 2", the resistance of the FTO under P3, and the contact resistance between the silver and FTO at P2. The resistance of the FTO under P3 is calculated according to the resistance calculation formula:

[0036]

[0037] The square resistance Rsh of FTO is 10Ω / □, the transmission length L is 50μm, and the transmission width W is 50mm. It can be calculated that the resistance is only 0.01Ω, which is much smaller than the contact resistance Rc and can be ignored.

[0038] Calculate the contact resistance: The contact resistance value R introduced by P2 laser scribing can be obtained by taking the difference between the two resistance measurement results. c , the calculation formula is:

[0039] R c =R t2 -R t1 (2)

[0040] Furthermore, the above idea can be used to introduce multiple sets of P1-P3 with the same parameters on the same substrate, such as Figure 4As shown, the P1-P3 laser-scribed areas and the areas not laser-cleared nearby are considered as the laser-scribed processing area 6 (in order to highlight this area, the proportion in the figure is a little larger than the actual situation). After the functional layers are prepared, the substrate is laser-scribed with P2 and the functional layer 4 is precisely cleared. After the silver vapor deposition is completed, the two probes of the milliohm meter are placed at the marked first contact 7 and the second contact 8 to perform the initial resistance measurement, and the measured result is recorded as R t3 Then, perform P3 marking on the laser-marked area 6, so that the silver and TCO are in ohmic contact and conductive only through the P2 marking portion on both sides of each laser-marked area 6. Use the two probes of the milliohmmeter to place the marked first contact 7 and second contact 8 for a second measurement, and record the measured results as R t4 Finally, the difference between the two measured resistances is divided by the number n of laser-scribing processing areas 6, which is the average contact resistance R introduced by the processing parameter P2. c ,Right now:

[0041] R c =(R t4 -R t3 ) / n (3)

[0042] Figure 5 The results of the initial and secondary resistance measurements using this method are shown. During the preparation process, multiple substrates were used. For the same substrate, ten laser scribing positions were selected for P2 scribing with the same laser power density. For different substrates, P2 scribing with different laser power densities was used, and P1 and P3 laser scribing were performed normally. According to formula (3), the contact resistance R corresponding to P2 scribing with different laser parameters can be obtained. c ,like Figure 6 As shown in the figure, it can be seen that when the laser power density is lower than 0.38μJ / cm 2 The contact resistance decreases with the increase of power density, indicating that within this parameter range, the insulating residues at the P2 laser scribe hinder the conduction of current. When the power density is higher than 0.38μJ / cm 2 When the contact resistance is about 0.08Ω, the contact resistance remains basically unchanged, indicating that the P2 laser scribing effect is better within this range.

[0043] Similarly, we can also introduce P2 scribing with different laser parameters on the same substrate to compare the resistance between adjacent contacts. Figure 4 In the embodiment, the P2 scribing effects of different laser parameters are compared by observing the secondary resistance measurement results between the third contact 9 and the fourth contact 10 and the secondary resistance measurement results between the fourth contact 10 and the fifth contact 11. This method can conveniently compare the P2 scribing effects of different laser parameters and quickly screen out the P2 laser parameters with the best scribing quality.

[0044] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this application.

[0045] It will be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for measuring the contact resistance introduced by P2 laser scribing in a perovskite solar module, characterized in that: The method comprises the following steps: (1) Sample preparation: The perovskite device that has completed the P1 and P2 laser scribing processes is used as the measurement sample. (2) Functional layer removal: Before evaporating the metal electrode, use laser to remove all functional layers on both sides of the laser-scribed area of ​​the sample to ensure that the metal electrode subsequently evaporated in the cleared area is in direct contact with the transparent conductive oxide layer TCO; (3) Metal electrode evaporation: After completing the above functional layer removal step, a metal electrode is evaporated on the sample surface. (4) Initial resistance measurement: Use a milliohmmeter to measure the resistance on both sides of the laser-marked area, record the total resistance Rt1 and mark the position of the milliohmmeter pen contact. (5) P3 scribing and secondary measurement: Perform the P3 laser scribing process so that the metal electrodes on both sides of the laser scribing area are only connected through the ohmic contact between the metal electrodes and the TCO at the P2 scribing location; and use a high-precision milliohm meter to measure the resistance at the marked position and record the total resistance Rt2. (6) Calculation of contact resistance: The contact resistance Rc caused by P2 laser scribing can be calculated by taking the difference between the resistance values ​​obtained from the two measurements.

2. The method according to claim 1, characterized in that The milliohm meter in step (4) has an accuracy of 0.001Ω, which is used to measure the accuracy of contact resistance.

3. The method according to claim 1, characterized in that The step (6) is specifically to select multiple positions on the same substrate for laser scribing, wherein the laser parameters of P2 scribing on the substrate are all kept consistent, and the resistance at both ends of all laser scribing areas is measured, and finally the average value of the contact resistance Rc is obtained by difference, specifically R c =(R t4 -R t3 ) / n, where Rt3 is the resistance measured at both ends of P3 before it is scratched, and Rt4 is the resistance measured at both ends of P3 after it is scratched. This method reduces the measurement error caused by different contact positions.

4. The method according to claim 3, characterized in that Multiple locations on the same substrate are selected for laser scribing, where the laser parameters for P2 scribing on the substrate are different. By calculating the contact resistance corresponding to P2 scribing with different laser parameters on the substrate, the P2 scribing effects with different laser parameters can be compared and the P2 laser parameters with the best scribing quality can be quickly screened out.

5. The method according to claim 3, characterized in that The conductive part resistance of the TCO layer below P3 adopts a TCO conductive substrate with a square resistance of less than 20Ω / □ to reduce the influence of the conductive part resistance of the TCO layer below P3.

6. The method according to claim 1, characterized in that During the measurement, the ambient temperature was kept at 20-25°C, the relative humidity was maintained between 20% and 60%, and the surface was kept clean.

7. The method according to claim 1, characterized in that During the laser marking process, it is necessary to grasp the mark and position it to ensure the accuracy of the laser marking.

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