Interface buffer layer assisted laser scribe defect mitigation method and structure based thereon

Abstract

The application discloses an interface buffer layer assisted laser scribing defect inhibition method and a structure based on the same, and belongs to the technical field of laser scribing process. The method disclosed by the application comprises the following steps: preparing a buffer layer between a layer to be scribed and an underlying functional layer; or preparing a buffer layer between the layer to be scribed and an upper functional layer; then performing laser scribing, so that laser acts on the buffer layer and the layer to be scribed; the buffer layer absorbs laser energy and produces physical or chemical changes in the laser scribing process, thereby inhibiting the generation of scribing defects; after the laser scribing is completed, the part of the buffer layer in the un-scribed area remains and serves as part of the functional layer; and the buffer layer is a thermal buffer layer, a spatter inhibition layer or a double-layer composite buffer layer. The technical problems of single function of the buffer layer, irreversible scribing damage, increased process steps and no consideration of subsequent covering in the prior art are solved.

Description

Technical Field

[0001] This invention belongs to the field of laser scribing technology, specifically relating to a laser scribing defect suppression method assisted by an interface buffer layer and a structure based thereon. Background Technology

[0002] Perovskite solar cells have emerged as a rising star in the photovoltaic field in recent years. The key to their widespread attention lies in their ability to be processed using an all-solution method, resulting in low production costs, minimal material usage, and the ability to be fabricated into flexible devices. This has demonstrated enormous potential in emerging applications such as building-integrated photovoltaics, wearable devices, and portable power supplies. Laser scribing technology is an indispensable step in achieving the leap from small-area laboratory devices to large-area industrial modules. Simply put, a large-area perovskite solar cell needs to be divided into multiple interconnected sub-cells, much like cutting a large battery into several smaller cells and then connecting them end-to-end. This ensures voltage stability while minimizing current loss. Laser scribing is the tool used to perform this precise division: scribing P1 first cuts away the bottom transparent conductive electrode, scribing P2 (perovskite layer scribing) peels away the middle perovskite light-absorbing layer, and scribing P3 (back electrode scribing) processes the top back electrode. Among them, marking lines on P2 and P3 is the most troublesome part, because perovskite materials are particularly sensitive to heat and mechanical shock, and laser marking can easily cause a series of problems.

[0003] In actual mass production, the edge morphology quality after scribing P2 and P3 is a key factor determining the series resistance between sub-cells and the device aging rate. When a laser acts on the perovskite layer or the back electrode metal layer, the instantaneous high temperature and shock wave-induced material spatter will redeposit on both sides of the scribing channel, causing the electrical isolation between adjacent sub-cells to fail. Edge curling and material decomposition introduce microcracks and pores between layers, making it impossible to achieve conformal coverage of functional layers subsequently prepared by physical vapor deposition or atomic layer deposition. These microstructural defects accelerate ion migration and electrode corrosion during damp heat aging tests, ultimately causing irreversible power decay of the module. Therefore, how to suppress laser-induced thermal-mechanical damage while ensuring scribing efficiency and accuracy has become one of the core challenges in the current industrialization of perovskite photovoltaics.

[0004] To address the aforementioned laser scribing damage problem, several solutions have been proposed in existing research and patents. The first type of solution focuses on optimizing laser parameters, including reducing output power, compressing pulse width to the picosecond or femtosecond range, and optimizing repetition frequency and scanning speed to minimize the heat-affected zone. However, limited by the low thermal decomposition threshold of perovskite materials and the rigid requirements of production lines for scribing throughput, the adjustable window for laser parameters is extremely narrow, making it difficult to balance cutting quality and production efficiency solely through parameter optimization. The second type of solution introduces an interface buffer layer to assist scribing. For example, Chinese patent application CN121510847A discloses a technical solution of pre-preparing an interface buffer layer before depositing a metal back electrode, aiming to alleviate film spatter and edge curling during P3 scribing. The third type of solution originates from academic research, constructing a two-dimensional / three-dimensional heterojunction encapsulation structure at the grain boundaries of the perovskite polycrystalline thin film. Utilizing the hydrophobicity and defect passivation function of two-dimensional perovskite, it suppresses non-radiative recombination and enhances the material's resistance to laser irradiation.

[0005] While the aforementioned solutions alleviate scribing damage to some extent, they still have significant shortcomings in mass production applications. First, existing buffer layer solutions have limited functionality: taking Yongjia Optoelectronics' patent as an example, its buffer layer primarily improves the film quality of the back electrode, offering limited thermal-mechanical buffering for the scribing process itself. Furthermore, it is only introduced before P3 scribing and does not cover the P2 scribing stage, failing to provide comprehensive protection throughout the entire process. Second, there is a lack of synergistic design between the buffer layer and the laser process. The material type, thickness, and preparation process (solution or vapor phase) of the buffer layer, along with laser parameters (power, pulse width, spot size), have not been jointly optimized. This results in the buffer layer being completely destroyed during scribing, or its own peeling fragments becoming new sources of contamination. Third, scribing damage is irreversible: even with a buffer layer, laser-induced localized heat accumulation and shock waves can still penetrate the buffer layer and damage the underlying perovskite or charge transport layer. Simultaneously, the buffer layer itself faces the risk of ablation and peeling. Furthermore, existing technologies do not address the geometric control of the edge morphology after scribing for subsequent coverage; that is, they do not consider how to guide the spatter to converge inward or form inclined sidewalls through the material and structural design of the buffer layer to facilitate conformal deposition of the back electrode. Finally, the additional introduction of a buffer layer inevitably increases the deposition process (e.g., adding a spin coating or evaporation step), reducing the production line's cycle efficiency, which contradicts the photovoltaic industry's core demands for low cost and high yield. In summary, existing solutions have significant shortcomings in terms of functional integration, synergistic optimization capabilities, damage suppression effects, and process compatibility. Summary of the Invention

[0006] The purpose of this invention is to provide a laser scribing defect suppression method assisted by an interface buffer layer and a structure based thereon, in order to solve the technical problems of existing methods such as the buffer layer having a single function, irreversible scribing damage, increased process steps, and lack of consideration for subsequent covering.

[0007] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a laser scribing defect suppression method assisted by an interface buffer layer, comprising the following steps: A buffer layer is prepared between the layer to be inscribed and the lower functional layer; or a buffer layer is prepared between the layer to be inscribed and the upper functional layer. Laser scribing is then performed, so that the laser acts on the buffer layer and the layer to be scribed. During the laser scribing process, the buffer layer absorbs laser energy and undergoes physical or chemical changes to suppress the generation of scribing defects. After the laser scribing is completed, the portion of the buffer layer located in the unscribed area is retained and serves as part of the functional layer. The buffer layer is a thermal buffer layer, a splash suppression layer, or a double-layer composite buffer layer.

[0008] Furthermore, when the buffer layer is a thermal buffer layer, the layer to be scribed is a perovskite layer, and the functional layer is an electron transport layer or a transparent conductive oxide layer located above or below the layer to be scribed. In this case, the laser scribing process is the P2 scribing process.

[0009] Furthermore, the material of the heat buffer layer is a wide-bandgap semiconductor material or a two-dimensional material; The wide bandgap semiconductor material includes NiO, SnO2, TiO2, MoO3, V2O5, or WO3; The two-dimensional material includes graphene or MoS2.

[0010] Furthermore, the thickness of the heat buffer layer is 5-20 nm; The thermal buffer layer has an absorption rate of 30-50% for the laser wavelength used in the P2 scribing process and a thermal conductivity of 5-20 W / m·K.

[0011] Furthermore, when the buffer layer is a sputter suppression layer, the layer to be scribed is a back electrode layer, and the functional layer is a perovskite layer or hole transport layer located above or below the layer to be scribed. In this case, the laser scribing process is the P3 scribing process.

[0012] Furthermore, the melting point of the material of the spatter suppression layer is lower than that of the material of the back electrode layer; The material of the splash suppression layer is a low-melting-point metal or alloy, or a conductive polymer; The low-melting-point metal or alloy includes Bi, Sn, In or alloys thereof; the conductive polymer includes PEDOT:PSS. The thickness of the sputtering suppression layer is 10-50 nm; the absorption rate of the sputtering suppression layer for the laser wavelength used for scribing P3 is greater than 80%.

[0013] Furthermore, the dual-layer composite buffer layer includes a lower thermal buffer layer and an upper splash suppression layer; The lower thermal buffer layer is located between the electron transport layer and the perovskite layer and is used to assist the P2 scribing process. The upper sputtering suppression layer is located between the perovskite layer and the back electrode layer and is used to assist the P3 scribing process. The P2 and P3 scribing processes use lasers of different wavelengths, enabling each layer to respond selectively to the corresponding wavelength.

[0014] Furthermore, the thickness of the lower thermal buffer layer is 5-10 nm, and the material is NiO; the thickness of the upper sputtering suppression layer is 10-20 nm, and the material is Bi; the P2 scribing process uses an ultraviolet laser with a wavelength of 355 nm; the P3 scribing process uses a green laser with a wavelength of 532 nm.

[0015] Furthermore, the buffer layer is prepared using atomic layer deposition, molecular layer deposition, plasma-enhanced chemical vapor deposition, thermal evaporation, electron beam evaporation, or sputtering methods.

[0016] This invention also discloses an interface buffer layer-assisted laser scribing defect suppression structure, prepared using the method described in the claims, comprising: A substrate, wherein a first functional layer is disposed on the surface of the substrate; A buffer layer is provided on the surface of the first functional layer; The buffer layer is provided with a layer to be marked; The buffer layer is used to absorb laser energy and generate physical changes during the laser scribing process to suppress scribing defects. After scribing is completed, the portion of the buffer layer located in the un-scibed area is retained and serves as part of the functional layer.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a laser scribing defect suppression method assisted by an interface buffer layer. By preparing a buffer layer between the layer to be scribed and the lower or upper functional layer, the controllable optical absorption characteristics of the buffer layer are used to achieve active redistribution of laser energy. During the laser scribing process, the buffer layer actively absorbs laser energy and undergoes physical changes (such as thermal dispersion or melting). This fundamentally suppresses irreversible damage such as film spatter, edge curling, and material decomposition caused by thermal effects and shock waves in traditional laser scribing. It systematically solves the technical problems of existing buffer layers having single function, irreversible scribing damage, increased process steps, and lack of consideration for subsequent covering.

[0018] Furthermore, this invention prepares a buffer layer with specific photothermal, mechanical, and chemical properties below or above the layer to be scribed. During the laser scribing process, the buffer layer simultaneously performs three functions: photothermal regulation (absorbing and dispersing laser energy), mechanical buffering (absorbing shock waves to reduce edge curling), and chemical modification (improving interface contact). This allows the improvement of scribing quality and subsequent functional optimization to be completed simultaneously in the same structural layer without the need for additional functional layers or post-processing steps. From the perspective of structural integration, this invention solves the technical defects of traditional buffer layers that have only a single function and passively bear damage.

[0019] Furthermore, this invention incorporates a buffer layer beneath the perovskite layer, which possesses moderate light absorption and heat dissipation capabilities, reducing the heat-affected zone, and can also be converted into a passivation layer. In other words, the buffer layer material (such as NiO) itself is a hole transport / passivation material required for perovskite solar cells. After scribing, it remains in the un-scribbed area, enabling in-situ passivation of defects at the perovskite bottom interface and reducing carrier recombination losses. This approach achieves a temporal rearrangement of "scribation assistance" and interface passivation. The passivation layer, which originally needed to be deposited after scribing, is now deposited before scribing, thus assisting the scribing process while retaining the passivation function without adding any net process steps.

[0020] Furthermore, the buffer layer disposed below the back electrode in this invention has a low melting point and good wettability with the electrode material. Under laser irradiation, it melts and encapsulates the spatter, while simultaneously reducing contact resistance. During P3 scribing, it preferentially absorbs laser energy (absorption rate >80%) and melts rapidly. The molten, low-viscosity material spontaneously encapsulates the spatter particles of the back electrode material through surface tension, increasing their mass and causing them to fall back or be captured. The spatter particle density is reduced by approximately 80%, and the spatter diffusion distance is reduced by approximately 87%. Simultaneously, the molten material flows into the microcracks at the scribing edge and solidifies to fill them, achieving in-situ passivation of edge defects and reducing edge roughness. After scribing is completed, the spatter suppression layer in the un-scibing area remains between the back electrode and the lower layer, which can reduce electrode contact resistance and reduce series resistance loss. This scheme allows the sacrificial layer, originally used only for spatter suppression, to also perform electrode modification functions, achieving the dual benefits of spatter suppression and performance improvement.

[0021] Furthermore, the dual-layer composite buffer layer structure of this invention includes both a thermal buffer layer and a sputtering suppression layer, which optimize the scribing quality of P2 and P3 respectively. Each layer selectively responds to different wavelengths of laser light. P2 scribing uses ultraviolet laser (355nm), with its energy primarily absorbed by the lower thermal buffer layer for heat dispersion. P3 scribing switches to green laser (532nm), with its energy primarily absorbed by the upper sputtering suppression layer for melting and encapsulation. This wavelength-layer matching design allows the two buffer layers to play a dominant role in their respective scribing processes without interfering with each other or being prematurely consumed.

[0022] Furthermore, this invention utilizes the spontaneous flow behavior of the buffer layer material after melting during the laser scribing process to achieve in-situ passivation of scribing edge defects. Under the influence of surface tension and capillary action, the molten buffer layer material automatically flows to the microcracks and uneven areas at the edge of the laser scribing, and after solidification, forms a smooth sloping transition zone (slope angle <30°) from the bottom to the top surface of the scribing, fundamentally solving the industry problem of difficult post-processing of scribing edge defects. Attached Figure Description

[0023] Figure 1 The diagram shows the structure obtained by performing the P2 scribing process using the laser scribing defect suppression method of the present invention. Figure 2 This is a structural diagram of the double-layer composite buffer layer of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0025] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0026] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0027] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0028] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0029] This invention provides a method for suppressing laser scribing defects with an interface buffer layer. A multifunctional sacrificial / conversion buffer layer is prepared below (or above) the layer to be scribed. This buffer layer has the following characteristics: Tunable photothermal conversion: The absorption coefficient of the laser wavelength is adjustable, allowing for selective absorption or reflection of laser energy; Thermal buffering capacity: It has appropriate thermal conductivity and can absorb and disperse local heat; Mechanical buffering capacity: It has a certain degree of toughness, can absorb shock waves, and reduce edge curling; Convertibility: After scribing, the buffer layer material can be converted into part of the functional layer (such as passivation layer, charge carrier transport layer) without removal.

[0030] This method designs different buffer layer schemes for the P2 and P3 line-drawing processes respectively: The P2 scribing process is performed after the perovskite layer is deposited. The goal is to locally remove the perovskite layer to expose the underlying electron transport layer or TCO. In the traditional P2 scribing process, the laser acts directly on the perovskite, and the heat-affected zone leads to perovskite decomposition, PbI2 residue, and edge defects. When performing the P2 line drawing process, the following steps are included: Before depositing the perovskite layer, a thermal buffer layer (5-20 nm thick) is prepared in advance. Step 1: The material of the heat buffer layer is a wide bandgap semiconductor material (such as NiO, SnO2, TiO2) or a two-dimensional material (such as graphene, MoS2); the heat buffer layer is prepared by atomic layer deposition or molecular layer deposition to ensure precise and controllable thickness; and the position of the heat buffer layer is located between the electron transport layer and the perovskite layer. Step 2: The P2 scribing process is then performed. The laser wavelength used in the P2 scribing process is (e.g., 355nm or 532nm). The heat buffer layer has a moderate absorption coefficient (absorption rate 30-50%), which can absorb some energy to generate local heating without excessive absorption and damaging the underlying layer. The heat buffer layer has a moderate thermal conductivity (5-20 W / m·K), which can quickly disperse local heat and avoid heat accumulation. It also matches the lattice of the perovskite material and does not affect the crystal quality of the perovskite. During the P2 scribing process, when the laser irradiates, some of the energy is absorbed by the heat buffer layer and converted into heat energy, causing the upper perovskite layer to decompose due to heat. At the same time, the buffer layer disperses the heat laterally, reducing the width of the heat-affected zone. The mechanical toughness of the buffer layer itself can absorb the laser shock wave and reduce edge curling. Step 3: After scribing, the surface of the thermal buffer layer in the exposed area can be used for subsequent functional layer deposition. The buffer layer in the un-scribbed area is retained and participates in device operation (e.g., as part of a hole / electron transport layer). The resulting structure is as follows: Figure 1 As shown.

[0031] The P3 scribing process is performed after the back electrode deposition, with the goal of locally removing the back electrode and perovskite layer to expose the underlying TCO. In traditional P3 scribing, sputtering and edge curling of the metal electrode are particularly severe problems.

[0032] When performing the P3 line drawing process, the following steps are included: Step 1: Before depositing the back electrode layer, prepare a sputtering suppression layer (10-50 nm thick). The material of the spatter suppression layer is a low-melting-point metal or alloy (such as Bi, Sn, In), or a conductive polymer (such as PEDOT:PSS); the preparation method of the spatter suppression layer is thermal evaporation, sputtering, or solution method. More importantly, the sputtering suppression layer has a lower melting point than the back electrode material (e.g., Ag has a melting point of 961°C, and Bi has a melting point of 271°C); it has good wettability with the back electrode material, can form a continuous thin film, and has a high absorption rate (>80%) for laser wavelength, ensuring that laser energy is mainly absorbed by this layer; Step 2: Then, the P3 scribing process is performed. During the P3 scribing process, when the laser is irradiated, the spatter suppression layer preferentially absorbs energy and melts rapidly. The molten suppression layer material wraps around the spatter particles of the upper back electrode material, causing them to re-coagulate and preventing spatter diffusion. At the same time, the molten material flows into the micro-cracks at the edge of the scribing, blunting edge defects. Since the suppression layer has a low melting point, scribing can be achieved at a lower energy, reducing thermal damage to the underlying perovskite layer. Step 3: After the P3 scribing process, the inhibition layer material in the scribing area is removed. The inhibition layer material remaining at the scribing edge forms a smooth transition area, which improves the coverage of the subsequent encapsulation layer. The inhibition layer in the unscribing area is retained, which can reduce the electrode contact resistance.

[0033] When the buffer layer is a double-layer composite buffer layer, the specific structure is as follows: Figure 2 As shown: Lower layer (adjacent to perovskite): thermal buffer / passivation layer, 5-10 nm thick, material such as NiO; Upper layer (adjacent to back electrode): sputter suppression layer, 10-20 nm thick, material such as Bi; When drawing lines with P2, the laser penetrates the upper layer (which is transparent to the P2 wavelength) and mainly acts on the lower layer and perovskite.

[0034] When scribing lines on P3, the laser wavelength is adjusted (e.g., switching from 355nm to 532nm). The upper layer has high absorption of the P3 wavelength, which plays a role in splatter suppression.

[0035] Buffer layer material alternatives: In addition to NiO, transition metal oxides such as MoO3, V2O5, and WO3 can be used; in addition to Bi, low-melting-point metals such as Sn, In, and Ga or their alloys can be used.

[0036] Alternative preparation methods: In addition to atomic layer deposition, molecular layer deposition and plasma-enhanced chemical vapor deposition can be used; in addition to thermal evaporation, electron beam evaporation and sputtering can be used.

[0037] Multi-layer structure alternative: A gradient component buffer layer can be used, with the material composition gradually changing from the bottom layer to the top layer, to achieve a better match of thermal and mechanical properties.

[0038] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0039] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0040] Example 1 A method for suppressing laser scribing defects assisted by an interface buffer layer (the buffer layer is a double-layer composite buffer layer) includes the following steps: Step 1: Substrate preparation and TCO (Transparent Conductive Oxide) deposition TCO (such as FTO or ITO) is deposited on a glass substrate, and P1 lines are scribed. Step 2: Deposit the lower thermal buffer layer (thermal buffer / passivation layer) Atomic layer deposition was used to deposit a 5 nm NiO layer on the TCO surface. The deposition parameters were: temperature 200 °C, precursors Ni(acac)2 and O3, and number of cycles 50. Step 3: Deposit electron transport layer A SnO2 electron transport layer (20 nm) was deposited on the NiO layer. Step 4: Deposit perovskite layer A perovskite layer (500 nm) with a composition of FA was deposited using a two-step or co-evaporation method. 0.95 Cs 0.05 PbI3; Step 5: P2 scribing (perovskite layer scribing) The laser parameters are: wavelength 355nm, power 1.5W, scanning speed 1m / s, and repetition frequency 100kHz. The scribing process involves the laser penetrating the perovskite layer, with some energy being absorbed by the underlying NiO buffer layer, thus dispersing the heat laterally and reducing the heat-affected zone. A patented multi-modal monitoring system is used to ensure that the scribing depth is precisely controlled at the bottom of the perovskite layer. Step 6: Deposit the upper splash suppression layer A 15 nm Bi layer was deposited by thermal evaporation with the following parameters: evaporation rate of 0.1 nm / s and substrate temperature of room temperature. Step 7: Deposit hole transport layer and back electrode Spiro-OMeTAD hole transport layer (150 nm) was deposited, followed by thermal evaporation deposition of Ag back electrode (100 nm). Step 8: P3 scribing (back electrode + perovskite layer scribing) Laser parameters: wavelength 532nm, power 0.8W, scanning speed 0.8m / s, repetition rate 50kHz. The scribing process: The laser energy is mainly absorbed by the Bi layer, which melts rapidly, encapsulates the Ag sputtering particles, and simultaneously flows into the passivation defects at the scribing edge. After marking, the marked area exposes the underlying TCO, completing the sub-cell isolation. Step 9: Packaging Then proceed with the subsequent packaging process.

[0041] The structure obtained in this embodiment was subjected to performance testing, and the following test data was obtained: 1) The Bi buffer layer can reduce the number of sputtering particles on the Ag electrode by more than 80%, and reduce the sputtering diffusion distance from the conventional 200μm to less than 30μm, indicating that the sputtering suppression rate of this structure is improved. 2) The NiO thermal buffer layer reduced the width of the heat-affected zone (HAZ) of the P2 scribing from 25 μm to 12 μm, decreasing the degree of perovskite decomposition by 60%. This structure reduces the HAZ size. 3) The mechanical buffering effect of the buffer layer reduces the curling height of the scribing edge from 150nm to 40nm, improving the continuity of the subsequent functional layer coverage and alleviating the edge curling.

[0042] 4) During the scribing process, molten Bi flows into the microcracks, achieving in-situ passivation of edge defects, reducing leakage current paths, and the buffer layer is transformed into part of the functional layer after scribing (NiO acts as a hole transport layer, and Bi reduces contact resistance), without the need for additional removal steps. 5) The overall effect improved the component yield from 85% to over 93%.

[0043] Example 2 A laser scribing defect suppression method assisted by an interface buffer layer (the buffer layer is a thermal buffer layer, assisting the P2 scribing process) includes the following steps: Step 1: Substrate preparation and TCO deposition A transparent conductive oxide TCO layer (FTO, 500 nm thick, sheet resistance 10 Ω / □) is deposited on a glass substrate, P1 lines are scribed, and part of the TCO is removed to form sub-cell spacers. Step 2: Deposit electron transport layer A SnO2 electron transport layer was deposited on the TCO surface using atomic layer deposition. The deposition parameters were as follows: precursor: tetra(dimethylamino)tin (TDMASn) and deionized water; deposition temperature: 120℃; number of cycles: 200; thickness: 20nm. Step 3: Deposit a thermal buffer layer A NiO thermal buffer layer was deposited on the surface of the SnO2 electron transport layer using atomic layer deposition. The deposition parameters were as follows: precursor: bis(ethylcyclopentadienyl)nickel (Ni(EtCp)2) and ozone (O3); deposition temperature: 200℃; number of cycles: 100; thickness: 8nm (allowable deviation ±1nm); thermal buffer layer characteristics: 42% absorption rate of 355nm ultraviolet laser and thermal conductivity of 12W / m·K. Step 4: Deposit perovskite layer Perovskite layers were deposited using a one-step solution coating method (FA). 0.85 Cs 0.15 PbI3), specific parameters are as follows: precursor solution: 1.5M FA 0.85 Cs 0.15 PbI3 was dissolved in a DMF:DMSO (volume ratio 4:1) mixed solvent; coating method: slot coating; wet film thickness: 15 μm; annealing conditions: anneal at 60℃ for 30 seconds, then anneal at 120℃ for 60 seconds; final perovskite layer thickness: 550 nm ± 20 nm. Step 5: P2 marking (heat buffer layer assisted marking) The P2 line was drawn using an ultraviolet laser with the following parameters: laser wavelength: 355nm; laser power: 1.8W; pulse width: 15ps; repetition rate: 100kHz; scanning speed: 1.2m / s; number of lines drawn: 1. The principle of scribing: When irradiated by 355nm ultraviolet laser, about 42% of the energy is absorbed by the 8nm NiO heat buffer layer below. NiO disperses the absorbed heat laterally, reducing the width of the heat-affected zone from the usual 30μm to 15μm. At the same time, the mechanical toughness of NiO absorbs the laser shock wave, reducing the curling height of the scribing edge of the perovskite layer from 160nm to 50nm. Step 6: Post-line processing After scribing, the scribed area exposes the underlying SnO2 electron transport layer, and the NiO thermal buffer layer in the exposed area is completely removed during the scribing process; the NiO thermal buffer layer in the un-scibbed area is retained and participates in device operation as a hole transport layer / passivation layer, which can reduce the defect density at the perovskite substrate interface (from 3×10⁻⁶). 16 cm -3 Reduced to 8×10 15 cm -3 ); Step 7: Subsequent functional layer deposition The following layers were deposited sequentially on the perovskite layer after scribing: hole transport layer: Spiro-OMeTAD (150 nm, spin coating); back electrode: Ag (100 nm, thermal evaporation, evaporation rate 0.2 nm / s). Step 8: Draw a line on P3 P3 lines were drawn using a green laser with the following parameters: wavelength 532nm, power 1.0W, and scanning speed 1.0m / s. Step 9: Packaging Then proceed with the subsequent packaging process.

[0044] Using a control group without a thermal buffer layer, and this embodiment using a thermal buffer layer, the test results obtained by comparing the two are shown in Table 1.

[0045] Table 1 Performance Comparison Data for No Thermal Buffer Layer and With Thermal Buffer Layer

[0046] Example 3 A laser scribing defect suppression method assisted by an interface buffer layer (the buffer layer is a spatter suppression layer, assisting the P3 scribing process) includes the following steps: Step 1: Substrate preparation and TCO deposition A TCO layer (ITO, 400 nm thick, sheet resistance 12 Ω / □) was deposited on a glass substrate, and P1 lines were scribed. Step 2: Deposit electron transport layer The SnO2 electron transport layer was deposited using a chemical bath deposition method, with the following specific parameters: precursor solution: 0.1 M MS nCl4·5H2O and 0.3 M thiourea dissolved in deionized water; deposition temperature: 70℃; deposition time: 120 minutes; thickness: 25 nm. Step 3: Deposit perovskite layer A two-step perovskite layer (MAPbI3) was deposited with the following parameters: Step 1: Spin-coating PbI2 solution (1.3 MPbI2 dissolved in DMF) at 2000 rpm for 30 seconds, followed by annealing at 100°C for 5 minutes, resulting in a thickness of 300 nm; Step 2: Immersion in MAI solution (10 mg / mL MAI dissolved in isopropanol) for 2 minutes, followed by annealing at 100°C for 15 minutes; Final perovskite layer thickness: 500 nm. Step 4: Draw a line on P2 P2 lines were drawn using an ultraviolet laser with the following parameters: wavelength 355nm, power 1.5W, and scanning speed 1.0m / s. Step 5: Deposit a splash suppression layer A Bi (bismuth) sputter suppression layer was deposited on the surface of a perovskite layer using a thermal evaporation method. The deposition parameters were as follows: evaporation source: Bi particles (99.999% purity); evaporation rate: 0.15 nm / s; substrate temperature: 25℃ (room temperature); vacuum degree: 5 × 10⁻⁶. -4 Pa; Thickness: 20nm (allowable deviation ±2nm); Sputtering suppression layer characteristics: 92% absorption rate of 532nm green laser, melting point 271℃, wetting angle with Ag electrode 25°; Step 6: Deposit back electrode An Ag back electrode was deposited on a Bi sputter suppression layer using a thermal evaporation method. The deposition parameters were as follows: evaporation source: Ag particles (99.99% purity); evaporation rate: 0.5 nm / s (first 10 nm), then accelerated to 1.0 nm / s; substrate temperature: 25℃ (room temperature); vacuum degree: 5 × 10⁻⁶ -4 Pa; Thickness: 120 nm; Step 7: P3 scribing (splatter suppression layer auxiliary scribing) P3 lines were drawn using a green laser with the following parameters: laser wavelength: 532nm; laser power: 0.9W; pulse width: 10ps; repetition rate: 50kHz; scanning speed: 0.9m / s; number of lines drawn: 1. The scribing principle is as follows: When irradiated with a 532nm green laser, about 92% of the energy is absorbed by the 20nm Bi sputtering suppression layer above. Bi melts rapidly (melting point 271℃, lower than Ag's 961℃). The molten Bi encapsulates the Ag sputtering particles, increasing the mass of the sputtering particles (from 0.5ng / particle to 2.3ng / particle). The particles fall back or are captured by the film below, reducing the sputtering diffusion distance from 200μm to 25μm. At the same time, under the action of surface tension, the molten Bi flows into the microcracks and uneven areas at the scribing edge, forming a smooth slope transition zone (slope angle 25°) after solidification, reducing the edge roughness from 85nm to 20nm. Step 8: Post-line processing After scribing, the Bi sputtering suppression layer and Ag back electrode within the scribed area are completely removed, exposing the underlying perovskite layer or electron transport layer; the Bi sputtering suppression layer in the unscribed area remains between the Ag back electrode and the perovskite layer, which can reduce the electrode contact resistance (from 0.8 Ω·cm). 2 Reduced to 0.3Ω·cm 2 ), reduce series resistance losses; Step 9: Packaging Then proceed with the subsequent packaging process.

[0047] Using a non-splatter suppression layer as a control group, this embodiment uses a Bi-splatter suppression layer. The test results obtained by comparing the two are shown in Table 2.

[0048] Table 2 Performance Comparison Data for No Splash Suppression Layer and With Splash Suppression Layer

[0049] The scribing quality was compared with that of control group A (without buffer layer) of conventional process, control group B (with only P3 front buffer layer) of Yongjia Optoelectronics scheme, and experimental group C of the present invention scheme (double-layer composite buffer layer - structure obtained in Example 1). The data are shown in Table 3 below.

[0050] Table 3 Comparison of P2 line quality

[0051] As can be seen from Table 3, when a double-layer composite buffer layer is used for protection, the fluctuation of P2 scribing depth is reduced by 50%, the degree of perovskite decomposition (PbI2 peak intensity) is reduced by 60%, the heat-affected zone of P2 is reduced by 50%, and the edge curling is reduced by 72%.

[0052] Table 4 Comparison of P3 line quality

[0053] As can be seen from Table 4, when a double-layer composite buffer layer is used for protection, the P3 scribing spatter suppression rate is 80%, the spatter diffusion distance is reduced by 87%, the scribing edge roughness is reduced by 74%, and the leakage current after scribing is reduced by 78%.

[0054] Table 5 Component Performance Comparison

[0055] As shown in Table 5, when a double-layer composite buffer layer is used for protection, the module yield increases by 9 percentage points, the module efficiency increases by 1.3 percentage points (absolute value), the yield increases by 9%, the aging stability is significantly improved, and the efficiency retention rate increases by 14 percentage points.

[0056] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for suppressing laser scribing defects assisted by an interface buffer layer, characterized in that, Includes the following steps: A buffer layer is prepared between the layer to be inscribed and the lower functional layer; or a buffer layer is prepared between the layer to be inscribed and the upper functional layer. Laser scribing is then performed, so that the laser acts on the buffer layer and the layer to be scribed. During the laser scribing process, the buffer layer absorbs laser energy and undergoes physical or chemical changes to suppress the generation of scribing defects. After the laser scribing is completed, the portion of the buffer layer located in the unscribed area is retained and serves as part of the functional layer. The buffer layer is a thermal buffer layer, a splash suppression layer, or a double-layer composite buffer layer.

2. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 1, characterized in that, When the buffer layer is a thermal buffer layer, the layer to be scribed is a perovskite layer, and the functional layer is an electron transport layer or a transparent conductive oxide layer located above or below the layer to be scribed. In this case, the laser scribing process is the P2 scribing process.

3. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 2, characterized in that, The material of the heat buffer layer is a wide-bandgap semiconductor material or a two-dimensional material; The wide bandgap semiconductor material includes NiO, SnO2, TiO2, MoO3, V2O5, or WO3; The two-dimensional material includes graphene or MoS2.

4. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 2, characterized in that, The thickness of the heat buffer layer is 5-20 nm; The thermal buffer layer has an absorption rate of 30-50% for the laser wavelength used in the P2 scribing process and a thermal conductivity of 5-20 W / m·K.

5. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 1, characterized in that, When the buffer layer is a sputter suppression layer, the layer to be scribed is a back electrode layer, and the functional layer is a perovskite layer or hole transport layer located above or below the layer to be scribed, the laser scribing process is the P3 scribing process.

6. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 3, characterized in that, The melting point of the material in the spatter suppression layer is lower than that of the material in the back electrode layer; The material of the splash suppression layer is a low-melting-point metal or alloy, or a conductive polymer; The low-melting-point metal or alloy includes Bi, Sn, In or alloys thereof; the conductive polymer includes PEDOT:PSS. The thickness of the sputtering suppression layer is 10-50 nm; the absorption rate of the sputtering suppression layer for the laser wavelength used for scribing P3 is greater than 80%.

7. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 1, characterized in that, The dual-layer composite buffer layer includes a lower thermal buffer layer and an upper splash suppression layer; The lower thermal buffer layer is located between the electron transport layer and the perovskite layer and is used to assist the P2 scribing process. The upper sputtering suppression layer is located between the perovskite layer and the back electrode layer and is used to assist the P3 scribing process. The P2 and P3 scribing processes use lasers of different wavelengths, enabling each layer to respond selectively to the corresponding wavelength.

8. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 7, characterized in that, The thickness of the lower thermal buffer layer is 5-10 nm, and the material is NiO; the thickness of the upper sputtering suppression layer is 10-20 nm, and the material is Bi; the P2 scribing process uses an ultraviolet laser with a wavelength of 355 nm; the P3 scribing process uses a green laser with a wavelength of 532 nm.

9. The laser scribing defect suppression method assisted by an interface buffer layer according to claim 1, characterized in that, The buffer layer is prepared by atomic layer deposition, molecular layer deposition, plasma-enhanced chemical vapor deposition, thermal evaporation, electron beam evaporation or sputtering.

10. A laser scribing defect suppression structure assisted by an interface buffer layer, characterized in that, Prepared by the preparation method according to any one of claims 1 to 9, comprising: A substrate, wherein a first functional layer is disposed on the surface of the substrate; A buffer layer is provided on the surface of the first functional layer; The buffer layer is provided with a layer to be marked; The buffer layer is used to absorb laser energy and generate physical changes during the laser scribing process to suppress scribing defects. After scribing is completed, the portion of the buffer layer located in the un-scibed area is retained and serves as part of the functional layer.

Images