Method for measuring contact resistance induced by p2 laser scribing in perovskite solar modules

Abstract

The present application relates to a method for measuring the contact resistance introduced by P2 laser scribing in a perovskite solar module, which can conveniently judge the quality of P2 scribing, and specifically, the contact resistance introduced by P2 laser scribing is directly calculated by comparing the measured resistance before and after P3 laser scribing. This method not only simplifies the test process, but also can compare the effects of different P2 parameters on the same substrate and the scribing effects of P2 scribing with the same parameters at different positions, greatly reducing the experimental difficulty, providing a reliable basis for optimizing laser parameters, and helping to improve the performance and reliability of the entire perovskite solar module.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology, and in particular relates to a method for measuring the contact resistance introduced by P2 laser scribing in a perovskite solar cell module. Background Technology

[0002] Laser scribing, as 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 fine patterning can be achieved. This technology not only ensures effective connectivity between individual cells but also significantly improves the overall performance and stability of the module.

[0003] Laser scribing plays a particularly crucial role in the P2 process. The main purpose of P2 laser scribing is to connect the top and bottom electrodes of adjacent sub-cells in series, thus forming a complete current path. However, improper P2 laser scribing can lead to a series of problems, such as excessive functional layer residue or severe damage to the bottom electrode, which can significantly impact module performance. Specifically, it manifests as higher contact resistance, which typically results in greater series resistance during IV testing, reducing the fill factor and ultimately affecting the photoelectric conversion efficiency of the perovskite solar cell module.

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

[0005] Therefore, there is an urgent need for a simple and accurate method to measure the contact resistance generated by P2 laser scribing, in order to quickly assess 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, in order to evaluate and optimize laser parameters, thereby improving the overall performance and reliability of the module. By comparing the resistance changes before and after P3 scribing, the contact resistance introduced by P2 laser scribing can be directly evaluated, which is of great significance for optimizing laser parameters.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for measuring the 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 process is used as the measurement sample.

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

[0011] (3) Metal electrode evaporation: After completing the above functional layer removal steps, metal electrodes are deposited on the sample surface.

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

[0013] (5) P3 scribing and secondary measurement: Perform the P3 laser scribing process to ensure that the metal electrodes on both sides of the laser scribing area are connected to the TCO only through the P2 scribing point, where the metal electrodes make ohmic contact. 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) Calculate the contact resistance: The contact resistance R caused by P2 laser scribing can be calculated by subtracting the resistance values ​​obtained from the two measurements. c .

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

[0016] Furthermore, in step (6), multiple locations on the same substrate are selected for laser scribing, wherein the laser parameters for scribing P2 on the substrate are kept consistent, and the resistance at both ends of the area containing all laser scribing lines is measured. Finally, the contact resistance R is calculated by subtracting the resistance at both ends. c The average value, specifically R c =(R t4 -R t3 ) / n, where R t3 The resistance between the two ends of P3 was measured before the marking was made, where R t4 This is the resistance measured at both ends after marking P3, which reduces the measurement error caused by different contact positions.

[0017] Furthermore, in step (6), multiple locations 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 P2 scribing with different laser parameters on the substrate, the P2 scribing effect of different laser parameters can be compared and the P2 laser parameter with the best scribing quality can be quickly selected.

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

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

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

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

[0022] Compared with existing technologies, this invention provides a measurement method that is structurally sound, easy to operate, and yields reliable results for evaluating the contact resistance at P2 laser-etched areas in perovskite solar cell modules. This method not only significantly simplifies the evaluation process of P2 laser etched effects but also enables rapid feedback and optimization of process parameters during research and production, thereby improving R&D efficiency and process stability. Furthermore, this method facilitates in-depth analysis of key factors leading to substandard device performance or unstable operation, such as uneven laser energy distribution, inconsistent etch depth, or poor metal layer adhesion, providing strong support for improving laser processing techniques and enhancing overall device performance.

[0023] Meanwhile, this invention overcomes the shortcomings of traditional evaluation methods, such as operational complexity, long processing time, and reliance on subjective judgment, and proposes a technical solution with strong repeatability, objective data, and applicability to standardized testing. This method, while ensuring measurement accuracy, lowers experimental conditions and technical barriers, facilitating wider application. Therefore, this invention not only has significant guiding significance in the research and industrialization of perovskite solar cells, but also provides a feasible reference path for the process evaluation of other thin-film photovoltaic devices, possessing excellent application prospects and socio-economic benefits. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the P2 laser and functional layer removal in the embodiment;

[0025] Figure 2 This is a 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 This is a schematic diagram illustrating the measurement of the contact resistance of multiple P2 laser-etched contacts in the embodiment;

[0028] Figure 5 The following diagram compares the primary and secondary resistance measurement results of substrates treated by P2 laser scribing with different laser parameters as an example.

[0029] Figure 6 The following is a comparison of contact resistance results for different laser parameters in the example.

[0030] Reference numerals: 1-Glass substrate; 2-Transparent conductive oxide layer; 3-Functional layer; 4-Functional layer to be removed; 5-Silver electrode; 6-Laser scribing area; 7-First contact; 8-Second contact; 9-Third contact; 10-Fourth contact; 11-Fifth contact. Detailed Implementation

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

[0032] Sample Preparation: A 5cm*5cm glass substrate 1 coated with a fluorine-doped tin oxide (FTO) layer was prepared. P1 laser scribing and marking were performed on the substrate, followed by ultrasonic cleaning in deionized water, acetone, and ethanol solutions sequentially. After nitrogen drying, the substrate was treated in a UV ozone cleaner for 15 minutes. After UV oxidation, a self-assembled monolayer (SAM) solution containing 1 mg / mL was spin-coated onto the cleaned FTO conductive glass substrate 1 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 another spin-coating at 5000 rpm for 30 seconds. During the last 5 seconds of spin-coating, 600 μL of antisolvent CB was added dropwise. After spin-coating, the substrate was annealed at 100°C for 30 minutes. Next, 300 μL of a PEAI solution containing 2 mg / mL was dynamically spin-coated at 4000 rpm for 30 s. Then, a PCBM solution containing 20 mg / mL was spin-coated at 1500 rpm for 60 s. Finally, 300 μL of a BCP solution containing 0.5 mg / mL was dynamically spin-coated at 4500 rpm for 25 s.

[0033] P2 scribing and functional layer removal: such as Figure 1As shown, P2 laser scribing is performed using a marker-based positioning method, where the parameters for P2 laser scribing are the parameters to be tested. Then, the laser is used again with marker-based positioning to precisely remove the functional layer 4 to be cleaned, ensuring that the subsequently deposited silver electrode 5 can fully contact the FTO in this area; while preserving the area of ​​functional layer 3 for subsequent P3 laser scribing.

[0034] Evaporation of silver electrode 5 and initial resistance measurement: such as Figure 2 As shown, an 80nm silver electrode 5 is deposited on the surface of the device by vapor deposition. Then, the resistance R is measured at the marked "contact 1" and "contact 2" using the two probes of a milliohm meter. t1 This resistor represents the resistance of the silver electrode between "Contact 1" and "Contact 2".

[0035] P3 Scribing and Secondary Resistance Measurement: (e.g.) Figure 3 As shown, laser scribing at point P3 is performed using a marker positioning method, ensuring that the metal electrodes on both sides of the laser scribing area 6 only achieve ohmic contact with the transparent conductive oxide layer 2 (TCO) at the scribing point P2, thus establishing conductivity. The resistance R at these points is then measured using the two probes of a milliohmmeter at the marked contact points 1 and 2, respectively. t2 This resistance represents the sum of the resistance of the silver electrode 5 between "contact 1" and "contact 2", the resistance of the FTO below P3, and the contact resistance between the silver and the FTO at P2. The resistance of the FTO below P3 is calculated using the following formula:

[0036]

[0037] The sheet resistance Rsh of the 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] Calculating contact resistance: The contact resistance value R introduced by P2 laser scribing can be obtained by subtracting the two resistance measurements. c The calculation formula is:

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

[0040] Furthermore, the above approach can be used to introduce multiple sets of P1-P3 with the same parameters on the same substrate, such as... Figure 4As shown, the laser scribing areas P1-P3 and the surrounding areas not removed by the laser are considered as the laser scribing processing area 6 (this area is enlarged in the figure to highlight its actual size). After the functional layers are fabricated, the substrate is precisely cleaned by laser scribing P2 and functional layer 4. After the silver evaporation is completed, the two probes of a milliohm meter are placed at the marked first contact point 7 and second contact point 8 to perform the initial resistance measurement, and the measured result is recorded as R. t3 Then, P3 scribing is performed at the laser scribing area 6, so that each laser scribing area 6 is conductive only through the P2 scribing portion within that area, creating an ohmic contact between silver and TCO. A milliohm meter is used to perform a second measurement at the marked first contact point 7 and second contact point 8, and the measurement result is recorded as R. t4 Finally, the difference between the two resistance measurements is divided by the number of laser scribing areas 6, n, which gives 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 To obtain the results of the initial and secondary resistance measurements using this method, multiple substrates were used during the preparation process. 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 calculated. c ,like Figure 6 As shown, it can be seen that when the laser power density is below 0.38 μJ / cm², 2 When the power density increases, the contact resistance decreases, indicating that within this parameter range, insulating residue at the P2 laser scribing site hinders current conduction. When the power density exceeds 0.38 J / cm², the contact resistance decreases. 2 At this time, the contact resistance remains basically unchanged at about 0.08Ω, indicating that the P2 laser scribing effect is good within this range.

[0043] Similarly, P2 scribing with different laser parameters can be introduced on the same substrate to compare the resistance between adjacent contacts. For example, in... Figure 4 In this study, the P2 scribing effect of different laser parameters was compared by observing the secondary resistance measurement results between the third contact 9 and the fourth contact 10 and the fourth contact 10 and the fifth contact 11. This method allows for convenient comparison of the P2 scribing effect of different laser parameters and quick selection of the P2 laser parameters with the best scribing quality.

[0044] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0045] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

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

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

3. The method according to claim 1, characterized in that, Step (6) specifically involves selecting multiple locations on the same substrate for laser scribing, ensuring that the laser parameters for scribing P2 on the substrate remain consistent, measuring the resistance at both ends of the area containing all laser scribing lines, and finally calculating the average value of the contact resistance Rc by subtracting the differences. ,in The resistance between the two ends of P3 was measured before the marking was made, where This is the resistance measured at both ends after marking P3, which reduces the measurement error caused by different contact positions.

4. The method according to claim 3, characterized in that, Laser scribing is performed at multiple locations on the same substrate, with different laser parameters for P2 scribing on the substrate. By calculating the contact resistance corresponding to P2 scribing with different laser parameters on the substrate, the scribing effect of different laser parameters can be compared and the P2 laser parameter with the best scribing quality can be quickly selected.

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

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

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

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