Diameter-dependent nanojoint formation and grain refinement in femtosecond laser nanojoining of AgNWs

Diameter-dependent nanojoint formation and grain refinement in femtosecond laser nanojoining of AgNWs | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Diameter-dependent nanojoint formation and grain refinement in femtosecond laser nanojoining of AgNWs Qiang Zhao, Xuewei Li, Minglu Chi, Xiao Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7917317/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Femtosecond (fs) laser has emerged as an effective technique for nanojoining. However, the role of nanowire diameter and the associated electric field distribution under fs laser irradiation in nanojoint formation and polycrystalline evolution remains unclear. In this study, AgNW nanojoints were fabricated via fs laser irradiation, and the electric field intensity distribution was simulated using the three-dimensional finite-difference time-domain (FDTD) method. Nanojoint formation was examined across nanowires of different diameters under consistent laser processing conditions. High-resolution transmission electron microscopy (TEM) revealed that smaller-diameter nanowires (e.g., 60 nm) facilitate nanojoint formation with a relative joint cross-sectional area reaching 653%, significantly exceeding those of 200 nm (81%) and 300 nm (39%) nanowires. Moreover, regions with higher electric field intensity exhibited refined polycrystalline grains, with an average size of 4.62 nm at the nanojoint interface—substantially smaller than that at non-bonded regions (16.38 nm and 36.14 nm). These findings provide new physical insights into the role of localized electromagnetic enhancement in joint morphology and grain structure regulation during fs laser nanojoining. Physical sciences/Materials science Physical sciences/Nanoscience and technology Physical sciences/Physics femtosecond laser nanojoint formation polycrystalline evolution electric field intensity distribution polycrystalline grains Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Owing to their excellent optical, electrical, and mechanical properties 1 – 5 , silver nanowire (AgNW) networks hold significant promise for numerous applications including flexible lighting 6 – 8 , artificial skin 9 , 10 , wearable devices 11 – 14 , and flexible energy storage devices 12 , 15 , 16 . As an important component of AgNW networks, Nanojoints have a significant impact on network performance 17 . Recently, methods for preparing AgNW nanojoints have primarily included solution processing 18 , mechanical pressing 19 , 20 , high-energy beam irradiation 21 – 23 , and intense light irradiation 24 – 26 , etc. Among these, femtosecond (fs) laser irradiation is considered an ideal method, offering high peak power, low thermal effects, and minimal collateral damage 27 , 28 . Liu et al. demonstrated that fs laser irradiation can initiate the formation of a nanojoints between two AgNWs, accompanied by the emergence of spherical-like nanostructures at their ends, highlighting the involvement of complex photothermal effects 29 . Liang et al. achieved welding of AgNWs by controlling the fs laser irradiation energy, revealing the low-damage ablation characteristic of fs laser 30 . Chen et al. investigated the melting behaviour and welding patterns of AgNW under fs irradiation during the formation of nanojoints 31 , demonstrating that the specific stacking and arrangement of silver nanowires constitutes the core mechanism for the disordered melting of AgNW networks. However, the influence of AgNW diameter on welded joint characteristics and the evolution of grain structure within these joints under fs laser irradiation remain unclear. In this study, the nanojoint were fabricated by using fs laser irradiation. Three-dimensional finite-difference time-domain (FDTD) method was employed to simulate the distribution of electric field intensity during the irradiation by fs laser. Nanojoint formation was observed in nanowires of different diameters under identical fs laser irradiation. Furthermore, polycrystalline grain size was analyzed across different regions of the same nanojoint. A high-resolution transmission electron microscopy (TEM) was utilized to analyze the change in crystalline structure of silver nanomaterials. It was found that under the identical fs laser irradiation, the smaller the diameter of the nanowires, the more readily nanojoints can be fabricated. Additionally, increased electric field intensity correlated with a decrease in polycrystalline grain size. Experiments Materials AgNWs suspension (20mg/ml) is purchased from XFNANO Materials (Jiangsu XFNANO Materials Tech Co., Ltd. Nanjing, China). The diameter of AgWNs ranges from 60 to 300 nm, and the length of AgNWs ranges from 7 to 13 µm. Silicon wafers are obtained from Shenshi materials (Shenshi Chemical Corporation Co.,LTD. Wuhan ,China). Sample Preparation To remove the polyvinylpyrrolidone (PVP) layers covering the AgNWs surfaces, the suspension was sonicated in 40 ℃ warm water for 20 s. Subsequently, the AgNWs suspension was concentrated via centrifugation at 4000 rpm. The clear supernatant was carefully decanted and discarded, leaving behind a high-concentration AgNWs paste. This paste was washed with deionized (DI) water to remove residual organics, followed by repeating the sonication and centrifugation steps. The purified AgNWs paste was then diluted with DI water, deposited dropwise onto the substrate, and air-dried. Laser irradiation In this work, the fs laser with a central wavelength 1030 nm, a pulse duration 800 fs and a repetition rate 200K Hz was employed. The laser scanning speed was set at 1000 mm/s, the spot diameter was 10 µm, the scanning point centre spacing was 5µm, and the laser scanning path spacing was 10 µm. Samples were welded using fs laser irradiation at fluences ranging from approximately 6 to 10 mJ/cm² Characterizations Scanning electron microscopy (SEM, MIRA 3 LMH, Czech Republic) was used to measure the surface morphology of AgNWs during fs laser irradiation. A focused ion beam (FIB, FEI Super X, USA) was used to prepare Transmission electron microscope (TEM) specimens. A high-resolution TEM (HR-TEM, Titan G2 60–300, USA) was employed to observe crystalline transformations within AgNWs nanojoints. Results and Discussion The AgNW samples irradiated by fs laser are labelled as AgNW-P, where P stands for diameter of AgNW in nm (Table 1). Figure 1(a1) shows a schematic diagram of fs laser irradiation of AgNWs, and Fig. 1(a2) exhibits two AgNWs with adjacent ends and perpendicular to each other. FDTD software is performed to calculate the electric field intensity distribution on the surfaces of AgNWs with diameters of 60 nm, 200 nm, and 300 nm under identical fs laser irradiation (wavelength: 1030 nm). All AgNWs are modeled with a length of 2 µm. Figure 1(b) presents top views of the simulation models, with insets displaying the electric field intensity at the nanowire ends, AgNW-60 exhibits the strongest surface electric field enhancement compared to AgNW-200 and AgNW-300. The maximum electric field intensity occurs at the end junction of AgNW-60, as shown in Fig. 1(b). Figure 2 shows the specific values of the electric field intensity on the surface of nanowires with different diameters (60 nm, 200 nm, 300 nm). Owing to the local geometric discontinuity in the nanowire regions32, the electric field strengths of AgWN-60, AgNW-200 and AgNW-300 are all at their own maximum at the X-coordinate of 0 (where the nanowire ends junction). The maximum electric field strength at the end junction of AgNW-60 is 12.91V/m, which is 1.56 times the maximum electric field strength at the end junction of AgNW-200 (8.29V/m), and 1.71 times of that at the end junction of AgNW-300 (7.54V/m), respectively. Surface morphology characterization was conducted using a TESCAN MIRA 3 LMH field emission scanning electron microscope (SEM). Figure 3(a-c) shows the morphology of nanojoints of AgNW-60, AgNW-200, and AgNW-300, after irradiation at the same fs laser power, respectively, indicated by the light blue dashed rectangle. In Fig. 3(a), the red ellipse represents the cross-sectional area of the nanowire, while the yellow ellipse indicates the cross-sectional area of the nanojoint. Figure 3(d) shows the relative area (ratio of the nonojoint cross-sectional area to the nanowire cross-sectional area) for different nanowires. When the nanowire diameter is 300 nm, the relative area is 39%. This value increases to 81% for a nanowire diameter of 200 nm, and reaches an average of 653% for the two nanojoints shown in Fig. 3(c) when the diameter is reduced to 60 nm. It can be clearly observed that the smaller the diameter of nanowires, the more obvious the formation of nanojoints. This is because the electric field strength is greater at the end of the small nanowire. The experimental results are perfectly consistent with the simulation results in Fig. 1(b) and Fig. 2. Figure 4(a1) schematically illustrates the fs laser irradiation of AgNWs. A partial enlargement of the purple dashed box in Fig. 4(a1) is shown in Fig. 4(a2), revealing two vertically oriented silver nanowires intersecting at a junction. FDTD simulations (Fig. 4(b1)) clearly indicate a localized maximum in electric field strength at this nanowire intersection. Figure 4(b2) provides an enlarged view of the marked region in Fig. 4(b1). Three reference lines are defined in Fig. 4(b2): the red dashed line ("Gap") corresponds to the intersection between AgNW A and AgNW B, the gray dashed line ("Top") lies within nanowire A, and the cyan dashed line ("Bottom") is positioned within nanowire B. As evident from the inset, the electric field strength along the "Gap" line significantly exceeds that along both the "Top" and "Bottom" lines. Figure 5 illustrates the electric field intensity profiles along the dashed lines labeled Top, Gap, and Bottom. The electric field intensity along the dashed line Gap is significantly higher than those along Top and Bottom. The maximum intensity along Gap (peaking at 2.59 V/m) occurs at an X-coordinate of 0.048. In contrast, the intensities along the dashed lines Top and Bottom remain nearly constant, reaching their maximum values of only 0.05 V/m and 0.005 V/m, respectively, at an X-coordinate of 0.10. A FEI Titan G2 60–300 high-resolution transmission electron microscopy (TEM) was employed to observe crystal change. A FEI Super X focused ion beam (FIB) was used for TEM sample preparation. Figure 6 shows the crystal structure of the AgNW material junction after fs laser irradiation. All Ag nanopolycrystals in Figs. 6(b-d) are marked with white wireframes, and the grain spacing of all the labelled polycrystals was calculated using Digital Micrograph software, and the grain size of all the polycrystals in Figs. 6–8(b-d) was measured using Nano Measurer software. Figure 6(a) shows the cross-section view of intersect AgNWs with laser irradiation. Figures 6(b-d) present TEM images showing different grain orientations within the Ag nanocrystals. Figure 6(b) is a magnified view of the region marked by the red circle in Fig. 6(a), with the corresponding selected area electron diffraction (SAED) pattern in the upper right corner. Well-defined Ag nanocrystalline grains are clearly observed in this magnified region. The average grain size was measured to be 16.38 nm. Measurements revealed that the lattice fringe spacings differed between grains, identifying two distinct values: 0.23 nm and 0.24 nm. Figure 6(c) shows a magnified view of the region marked by the light cyan circle in Fig. 6(a), with the corresponding SAED pattern displayed in the upper right corner. Distinct Ag nanocrystalline grains are also observable here, exhibiting an average grain size of 36.14 nm. Furthermore, Ag nanoparticles were also observed here with a grain size of 36.14 nm and a lattice spacing of 0.25 nm. Figure 6(d) corresponds to the magnified region marked by the purple circle in Fig. 6(a), featuring the corresponding SAED pattern in the upper right corner. The polycrystalline nature is more pronounced in this area, with multiple lattice fringe spacings appearing within the Ag nanocrystalline grains. The average grain size measured here is 4.62 nm, corresponding to 28.75% of the average grain size in Fig. 6(b) (16.38 nm) and 13.03% of that in Fig. 6(c) (36.14 nm). At the bonding interfaces of the Ag nanomaterials under fs laser irradiation, the grain size is smaller, while it is larger at the non-bonding interfaces. This phenomenon is attributed to the non-uniform distribution of electric field. Specifically, the electric field strength at the bonding interfaces is significantly higher than at the non-bonding interfaces under fs laser irradiation. This finding is highly consistent with the simulation results presented in Figs. 4 and 5. Conclusion In summary, AgNWs nanojoints were fabricated by fs laser irradiation. It was found that the electric field strength has a significant effect on the formation of nanojoints and the refinement of polycrystalline grains. AgNW-60, exhibiting the highest electric field strength at their ends, produced nanojoints with a relative area (ratio of the nonojoint cross-sectional area to the nanowire cross-sectional area) reaching 653%. This significantly exceeds the ratios observed for AgNW-200 (81%) and AgNW-300 (39%) nanojoints. In addition, at the nanojunction bonding interface exhibiting the highest electric field strength, the measured polycrystalline grain size is 4.62 nm. This is much smaller than the grain sizes measured at non-bonding interfaces (16.38 nm and 36.14 nm). This study provides new physical insights into the relationship between electric field strength at nanomaterial surfaces and the resulting nanojoint morphology and polycrystalline grain structure after fs laser irradiation. Declarations Author contributions Q.Z. designed and performed the experiments, collected the data, and wrote the manuscript. M.C. and X.L. helped in experimental data analysis. X. L. contributed to manuscript. All authors discussed the progress of the research and reviewed the manuscript. Funding This research was funded by Key Research Projects of Higher Education Institutions in Henan Province (Grant No. 24A460003), the General program of Henan Natural Science Foundation (Grant No. 252300420022), Central Guided Local Science and Technology Development Fund Program of Henan Province (Grant No. Z20241471072), and Henan Institute of Technology High-Level Talent Research Start-up Fund (Grant No. KQ2307). Competiing intersts The authors declare no competing interests. Data availability The data used to support the findings of this study are available from the corresponding author and first author upon request. References Bian, M. et al. Chemically Welding Silver Nanowires toward Transferable and Flexible Transparent Electrodes in Heaters and Double-Sided Perovskite Solar Cells. ACS Appl. Mater. Interfaces . 15 , 13307–13318 (2023). Patil, J. J. et al. Stability of Transparent Electrodes Based on Metal Nanowire Networks. Adv. Mater. 33 , e2004356 (2021). Duc, T. 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Flash-induced nanowelding of silver nanowire networks for transparent stretchable electrochromic devices. Sci. Rep. 8 , 2763 (2018). Wu, Z. et al. Flexible Transparent Electrode Based on Ag Nanowires: Ag Nanoparticles Co-Doped System for Organic Light-Emitting Diodes. Materials (Basel) 17 , (2024). Hu, Y. et al. Femtosecond-Laser-Ablated Porous Silver Nanowire Heater with Ultralow Driven-Voltage and Ultrafast Sensitivity for Highly Efficient Crude Oil Remedy. Nano Lett. 25 , 1520–1527 (2025). Hu, Y. et al. Enhancement of the Conductivity and Uniformity of Silver Nanowire Flexible Transparent Conductive Films by Femtosecond Laser-Induced Nanowelding. Nanomaterials (Basel) 9 , (2019). Liu, L. et al. Highly localized heat generation by femtosecond laser induced plasmon excitation in Ag nanowires. Applied Phys. Letters 102 , (2013). Liang, C. et al. Surface ablation thresholds of femtosecond laser micropatterning silver nanowires network on flexible substrate. Microelectronic Engineering 232 , (2020). Chen, C. et al. Welding Mechanisms in Silver Nanowires under Femtosecond Laser Irradiation for Reduced Sheet Resistance Electrode Fabrication. ACS Appl. Nano Mater. 8 , 4885–4898 (2025). Kuppe, C., Rusimova, K. R., Ohnoutek, L., Slavov, D. & Valev, V. K. Hot in Plasmonics: Temperature-Related Concepts and Applications of Metal Nanostructures. Advanced Opt. Materials 8 , (2019). Tables Table 1 The diameter and label of silver materials. Sample diameter and length are also listed. Category a b c Diameter (nm) 60 200 300 Label/AgNW-P AgNW-60 AgNW-200 AgNW-300 Additional Declarations No competing interests reported. Supplementary Files supplementaryinformation.pdf Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 28 Oct, 2025 Editor assigned by journal 26 Oct, 2025 Submission checks completed at journal 26 Oct, 2025 First submitted to journal 21 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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18:15:48","extension":"html","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":76647,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/275dd04021a530b4fc12fcc4.html"},{"id":94584557,"identity":"56d19fbb-8dca-46da-b44d-7ffa075ffda6","added_by":"auto","created_at":"2025-10-28 18:15:22","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":366601,"visible":true,"origin":"","legend":"\u003cp\u003e(a1) Schematic illustration of fs laser irradiation of Ag nanowires. (a2) Local enlargement of the purple dashed box in Fig. 1(a1). Distribution of electric vector in two vertical AgNWs with diameters of 60 nm (b1), 200 nm(b2), and 300 nm(b3).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/9f51a84cf52cf63d814cfaf2.png"},{"id":94584567,"identity":"eaae2c33-824d-4014-adc7-9b6f34824538","added_by":"auto","created_at":"2025-10-28 18:15:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":181754,"visible":true,"origin":"","legend":"\u003cp\u003eElectric vector intensity of AgNWs with diameters of 60 nm, 200 nm, and 300 nm.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/82717346c4d4ca51f7f11d94.png"},{"id":94584799,"identity":"774b437d-6c41-4b5a-a947-1e099e75383d","added_by":"auto","created_at":"2025-10-28 18:15:39","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":483484,"visible":true,"origin":"","legend":"\u003cp\u003eMorphology of nanojoints connected to the ends of the vertical nanowires with diameters of (a) 300 nm, (b) 200 nm, and (c) 60 nm. (d) Relative area of nanojoints of nanowire with diameters of 300 nm, 200 nm, and 60 nm. 653% represents the average relative area of the two nanojoints in AgNW-60.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/38a33de37bca84fc115e056c.png"},{"id":94584807,"identity":"23a2566f-f317-4c3f-b984-d1167aa3eeed","added_by":"auto","created_at":"2025-10-28 18:15:39","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":312314,"visible":true,"origin":"","legend":"\u003cp\u003e(a1) Schematic of fs laser irradiation of AgNWs. (a2) A partial enlargement of the purple dashed box in Fig. 4(a1). (b1) Cross-sectional electric field distribution at nanowires nanojoint calculated by FDTD. (b2) A partial enlargement of the purple dashed box in Fig.4 (b1) .\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/9ca5c7836a423930c86d6c51.png"},{"id":94585424,"identity":"b87f7b6a-043b-4ff9-8840-17e28e60602a","added_by":"auto","created_at":"2025-10-28 18:16:09","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":164402,"visible":true,"origin":"","legend":"\u003cp\u003eElectric field strength at the three dashed lines Top, Gap, Bottom.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/2073cee481b16d90c7cf7185.png"},{"id":94584810,"identity":"9bb1be67-d7c5-41b2-98bb-78f4021a3c32","added_by":"auto","created_at":"2025-10-28 18:15:40","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":632117,"visible":true,"origin":"","legend":"\u003cp\u003eTEM image of Ag nanowire material after fs laser irradiation. White squares indicate polycrystalline grains of the nanomaterials. (a) TEM image of the interconnections of Ag nanowire materials. (b) TEM image corresponding to the red circle in Fig. (a), with the corresponding SAED image in the upper right corner. (c) TEM image corresponding to the light cyan circle in Fig. 6(a), with the corresponding SAED image in the upper right corner. (d) TEM image corresponding to the purple circle in Figs. 6(a), with the corresponding SAED image in the upper right corner.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/07baa0aa6404400552b259fe.png"},{"id":94545493,"identity":"4666fbe6-5bb3-4358-97c6-cc51642a3f9b","added_by":"auto","created_at":"2025-10-28 17:37:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":392103,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/a4a3d975-094a-48a5-8cab-cd1bcae5dd3c.pdf"},{"id":94586347,"identity":"0b2fb968-033b-42ff-a71f-c7c5b61b1efd","added_by":"auto","created_at":"2025-10-28 18:16:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":215925,"visible":true,"origin":"","legend":"","description":"","filename":"supplementaryinformation.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7917317/v1/72ed28482f981ef8c969d858.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Diameter-dependent nanojoint formation and grain refinement in femtosecond laser nanojoining of AgNWs","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOwing to their excellent optical, electrical, and mechanical properties\u003csup\u003e\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e, silver nanowire (AgNW) networks hold significant promise for numerous applications including flexible lighting\u003csup\u003e\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e, artificial skin\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e, wearable devices\u003csup\u003e\u003cspan additionalcitationids=\"CR12 CR13\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e, and flexible energy storage devices\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. As an important component of AgNW networks, Nanojoints have a significant impact on network performance\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Recently, methods for preparing AgNW nanojoints have primarily included solution processing\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e, mechanical pressing\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e, high-energy beam irradiation\u003csup\u003e\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e, and intense light irradiation\u003csup\u003e\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e, etc. Among these, femtosecond (fs) laser irradiation is considered an ideal method, offering high peak power, low thermal effects, and minimal collateral damage\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eLiu et al. demonstrated that fs laser irradiation can initiate the formation of a nanojoints between two AgNWs, accompanied by the emergence of spherical-like nanostructures at their ends, highlighting the involvement of complex photothermal effects\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. Liang et al. achieved welding of AgNWs by controlling the fs laser irradiation energy, revealing the low-damage ablation characteristic of fs laser\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. Chen et al. investigated the melting behaviour and welding patterns of AgNW under fs irradiation during the formation of nanojoints\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e, demonstrating that the specific stacking and arrangement of silver nanowires constitutes the core mechanism for the disordered melting of AgNW networks. However, the influence of AgNW diameter on welded joint characteristics and the evolution of grain structure within these joints under fs laser irradiation remain unclear.\u003c/p\u003e\u003cp\u003eIn this study, the nanojoint were fabricated by using fs laser irradiation. Three-dimensional finite-difference time-domain (FDTD) method was employed to simulate the distribution of electric field intensity during the irradiation by fs laser. Nanojoint formation was observed in nanowires of different diameters under identical fs laser irradiation. Furthermore, polycrystalline grain size was analyzed across different regions of the same nanojoint. A high-resolution transmission electron microscopy (TEM) was utilized to analyze the change in crystalline structure of silver nanomaterials. It was found that under the identical fs laser irradiation, the smaller the diameter of the nanowires, the more readily nanojoints can be fabricated. Additionally, increased electric field intensity correlated with a decrease in polycrystalline grain size.\u003c/p\u003e"},{"header":"Experiments","content":"\u003cp\u003e\u003cb\u003eMaterials\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAgNWs suspension (20mg/ml) is purchased from XFNANO Materials (Jiangsu XFNANO Materials Tech Co., Ltd. Nanjing, China). The diameter of AgWNs ranges from 60 to 300 nm, and the length of AgNWs ranges from 7 to 13 \u0026micro;m. Silicon wafers are obtained from Shenshi materials (Shenshi Chemical Corporation Co.,LTD. Wuhan ,China).\u003c/p\u003e\u003cp\u003e\u003cb\u003eSample Preparation\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eTo remove the polyvinylpyrrolidone (PVP) layers covering the AgNWs surfaces, the suspension was sonicated in 40 ℃ warm water for 20 s. Subsequently, the AgNWs suspension was concentrated via centrifugation at 4000 rpm. The clear supernatant was carefully decanted and discarded, leaving behind a high-concentration AgNWs paste. This paste was washed with deionized (DI) water to remove residual organics, followed by repeating the sonication and centrifugation steps. The purified AgNWs paste was then diluted with DI water, deposited dropwise onto the substrate, and air-dried.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eLaser irradiation\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eIn this work, the fs laser with a central wavelength 1030 nm, a pulse duration 800 fs and a repetition rate 200K Hz was employed. The laser scanning speed was set at 1000 mm/s, the spot diameter was 10 \u0026micro;m, the scanning point centre spacing was 5\u0026micro;m, and the laser scanning path spacing was 10 \u0026micro;m. Samples were welded using fs laser irradiation at fluences ranging from approximately 6 to 10 mJ/cm\u0026sup2;\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eCharacterizations\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eScanning electron microscopy (SEM, MIRA 3 LMH, Czech Republic) was used to measure the surface morphology of AgNWs during fs laser irradiation. A focused ion beam (FIB, FEI Super X, USA) was used to prepare Transmission electron microscope (TEM) specimens. A high-resolution TEM (HR-TEM, Titan G2 60\u0026ndash;300, USA) was employed to observe crystalline transformations within AgNWs nanojoints.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eThe AgNW samples irradiated by fs laser are labelled as AgNW-P, where P stands for diameter of AgNW in nm (Table\u0026nbsp;1).\u003c/p\u003e\u003cp\u003eFigure 1(a1) shows a schematic diagram of fs laser irradiation of AgNWs, and Fig.\u0026nbsp;1(a2) exhibits two AgNWs with adjacent ends and perpendicular to each other. FDTD software is performed to calculate the electric field intensity distribution on the surfaces of AgNWs with diameters of 60 nm, 200 nm, and 300 nm under identical fs laser irradiation (wavelength: 1030 nm). All AgNWs are modeled with a length of 2 \u0026micro;m. Figure\u0026nbsp;1(b) presents top views of the simulation models, with insets displaying the electric field intensity at the nanowire ends, AgNW-60 exhibits the strongest surface electric field enhancement compared to AgNW-200 and AgNW-300. The maximum electric field intensity occurs at the end junction of AgNW-60, as shown in Fig.\u0026nbsp;1(b).\u003c/p\u003e\u003cp\u003eFigure 2 shows the specific values of the electric field intensity on the surface of nanowires with different diameters (60 nm, 200 nm, 300 nm). Owing to the local geometric discontinuity in the nanowire regions32, the electric field strengths of AgWN-60, AgNW-200 and AgNW-300 are all at their own maximum at the X-coordinate of 0 (where the nanowire ends junction). The maximum electric field strength at the end junction of AgNW-60 is 12.91V/m, which is 1.56 times the maximum electric field strength at the end junction of AgNW-200 (8.29V/m), and 1.71 times of that at the end junction of AgNW-300 (7.54V/m), respectively.\u003c/p\u003e\u003cp\u003eSurface morphology characterization was conducted using a TESCAN MIRA 3 LMH field emission scanning electron microscope (SEM). Figure\u0026nbsp;3(a-c) shows the morphology of nanojoints of AgNW-60, AgNW-200, and AgNW-300, after irradiation at the same fs laser power, respectively, indicated by the light blue dashed rectangle. In Fig.\u0026nbsp;3(a), the red ellipse represents the cross-sectional area of the nanowire, while the yellow ellipse indicates the cross-sectional area of the nanojoint. Figure\u0026nbsp;3(d) shows the relative area (ratio of the nonojoint cross-sectional area to the nanowire cross-sectional area) for different nanowires. When the nanowire diameter is 300 nm, the relative area is 39%. This value increases to 81% for a nanowire diameter of 200 nm, and reaches an average of 653% for the two nanojoints shown in Fig.\u0026nbsp;3(c) when the diameter is reduced to 60 nm.\u003c/p\u003e\u003cp\u003eIt can be clearly observed that the smaller the diameter of nanowires, the more obvious the formation of nanojoints. This is because the electric field strength is greater at the end of the small nanowire. The experimental results are perfectly consistent with the simulation results in Fig.\u0026nbsp;1(b) and Fig.\u0026nbsp;2.\u003c/p\u003e\u003cp\u003eFigure 4(a1) schematically illustrates the fs laser irradiation of AgNWs. A partial enlargement of the purple dashed box in Fig.\u0026nbsp;4(a1) is shown in Fig.\u0026nbsp;4(a2), revealing two vertically oriented silver nanowires intersecting at a junction. FDTD simulations (Fig.\u0026nbsp;4(b1)) clearly indicate a localized maximum in electric field strength at this nanowire intersection. Figure\u0026nbsp;4(b2) provides an enlarged view of the marked region in Fig.\u0026nbsp;4(b1). Three reference lines are defined in Fig.\u0026nbsp;4(b2): the red dashed line (\"Gap\") corresponds to the intersection between AgNW A and AgNW B, the gray dashed line (\"Top\") lies within nanowire A, and the cyan dashed line (\"Bottom\") is positioned within nanowire B. As evident from the inset, the electric field strength along the \"Gap\" line significantly exceeds that along both the \"Top\" and \"Bottom\" lines.\u003c/p\u003e\u003cp\u003eFigure\u0026nbsp;5 illustrates the electric field intensity profiles along the dashed lines labeled Top, Gap, and Bottom. The electric field intensity along the dashed line Gap is significantly higher than those along Top and Bottom. The maximum intensity along Gap (peaking at 2.59 V/m) occurs at an X-coordinate of 0.048. In contrast, the intensities along the dashed lines Top and Bottom remain nearly constant, reaching their maximum values of only 0.05 V/m and 0.005 V/m, respectively, at an X-coordinate of 0.10.\u003c/p\u003e\u003cp\u003eA FEI Titan G2 60\u0026ndash;300 high-resolution transmission electron microscopy (TEM) was employed to observe crystal change. A FEI Super X focused ion beam (FIB) was used for TEM sample preparation.\u003c/p\u003e\u003cp\u003eFigure 6 shows the crystal structure of the AgNW material junction after fs laser irradiation. All Ag nanopolycrystals in Figs.\u0026nbsp;6(b-d) are marked with white wireframes, and the grain spacing of all the labelled polycrystals was calculated using Digital Micrograph software, and the grain size of all the polycrystals in Figs.\u0026nbsp;6\u0026ndash;8(b-d) was measured using Nano Measurer software.\u003c/p\u003e\u003cp\u003eFigure\u0026nbsp;6(a) shows the cross-section view of intersect AgNWs with laser irradiation. Figures\u0026nbsp;6(b-d) present TEM images showing different grain orientations within the Ag nanocrystals. Figure\u0026nbsp;6(b) is a magnified view of the region marked by the red circle in Fig.\u0026nbsp;6(a), with the corresponding selected area electron diffraction (SAED) pattern in the upper right corner. Well-defined Ag nanocrystalline grains are clearly observed in this magnified region. The average grain size was measured to be 16.38 nm. Measurements revealed that the lattice fringe spacings differed between grains, identifying two distinct values: 0.23 nm and 0.24 nm. Figure\u0026nbsp;6(c) shows a magnified view of the region marked by the light cyan circle in Fig.\u0026nbsp;6(a), with the corresponding SAED pattern displayed in the upper right corner. Distinct Ag nanocrystalline grains are also observable here, exhibiting an average grain size of 36.14 nm. Furthermore, Ag nanoparticles were also observed here with a grain size of 36.14 nm and a lattice spacing of 0.25 nm. Figure\u0026nbsp;6(d) corresponds to the magnified region marked by the purple circle in Fig.\u0026nbsp;6(a), featuring the corresponding SAED pattern in the upper right corner. The polycrystalline nature is more pronounced in this area, with multiple lattice fringe spacings appearing within the Ag nanocrystalline grains. The average grain size measured here is 4.62 nm, corresponding to 28.75% of the average grain size in Fig.\u0026nbsp;6(b) (16.38 nm) and 13.03% of that in Fig.\u0026nbsp;6(c) (36.14 nm).\u003c/p\u003e\u003cp\u003eAt the bonding interfaces of the Ag nanomaterials under fs laser irradiation, the grain size is smaller, while it is larger at the non-bonding interfaces. This phenomenon is attributed to the non-uniform distribution of electric field. Specifically, the electric field strength at the bonding interfaces is significantly higher than at the non-bonding interfaces under fs laser irradiation. This finding is highly consistent with the simulation results presented in Figs.\u0026nbsp;4 and 5.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, AgNWs nanojoints were fabricated by fs laser irradiation. It was found that the electric field strength has a significant effect on the formation of nanojoints and the refinement of polycrystalline grains. AgNW-60, exhibiting the highest electric field strength at their ends, produced nanojoints with a relative area (ratio of the nonojoint cross-sectional area to the nanowire cross-sectional area) reaching 653%. This significantly exceeds the ratios observed for AgNW-200 (81%) and AgNW-300 (39%) nanojoints. In addition, at the nanojunction bonding interface exhibiting the highest electric field strength, the measured polycrystalline grain size is 4.62 nm. This is much smaller than the grain sizes measured at non-bonding interfaces (16.38 nm and 36.14 nm). This study provides new physical insights into the relationship between electric field strength at nanomaterial surfaces and the resulting nanojoint morphology and polycrystalline grain structure after fs laser irradiation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eQ.Z. designed and performed the experiments, collected the data, and wrote the manuscript. M.C. and X.L. helped in experimental data analysis. X. L. contributed to manuscript. All authors discussed the progress of the research and reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was funded by Key Research Projects of Higher Education Institutions in Henan Province (Grant No. 24A460003), the General program of Henan Natural Science Foundation (Grant No. 252300420022), Central Guided Local Science and Technology Development Fund Program of Henan Province (Grant No. Z20241471072), and Henan Institute of Technology High-Level Talent Research Start-up Fund (Grant No. KQ2307).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompetiing intersts\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used to support the findings of this study are available from the corresponding author and first author upon request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBian, M. et al. Chemically Welding Silver Nanowires toward Transferable and Flexible Transparent Electrodes in Heaters and Double-Sided Perovskite Solar Cells. \u003cem\u003eACS Appl. Mater. Interfaces\u003c/em\u003e. \u003cb\u003e15\u003c/b\u003e, 13307\u0026ndash;13318 (2023).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePatil, J. J. et al. Stability of Transparent Electrodes Based on Metal Nanowire Networks. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e, e2004356 (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDuc, T. V., Nguyen, V. C. \u0026amp; Kim, H. C. Analysis of the characteristics of silver nanowires (AgNW) random network for transparent heater applications. \u003cem\u003eNanotechnology\u003c/em\u003e \u003cb\u003e35\u003c/b\u003e, (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQin, C. et al. 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Welding Mechanisms in Silver Nanowires under Femtosecond Laser Irradiation for Reduced Sheet Resistance Electrode Fabrication. \u003cem\u003eACS Appl. Nano Mater.\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e, 4885\u0026ndash;4898 (2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKuppe, C., Rusimova, K. R., Ohnoutek, L., Slavov, D. \u0026amp; Valev, V. K. Hot in Plasmonics: Temperature-Related Concepts and Applications of Metal Nanostructures. \u003cem\u003eAdvanced Opt. Materials\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e, (2019).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cdiv class=\"SimplePara\"\u003eThe diameter and label of silver materials. Sample diameter and length are also listed.\u003c/div\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eCategory\u003c/div\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003ea\u003c/div\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cdiv class=\"SimplePara\"\u003eb\u003c/div\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cdiv class=\"SimplePara\"\u003ec\u003c/div\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eDiameter (nm)\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003e60\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cdiv class=\"SimplePara\"\u003e200\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cdiv class=\"SimplePara\"\u003e300\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cdiv class=\"SimplePara\"\u003eLabel/AgNW-P\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cdiv class=\"SimplePara\"\u003eAgNW-60\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cdiv class=\"SimplePara\"\u003eAgNW-200\u003c/div\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cdiv class=\"SimplePara\"\u003eAgNW-300\u003c/div\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003cbr/\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"femtosecond laser, nanojoint formation, polycrystalline evolution, electric field intensity distribution, polycrystalline grains","lastPublishedDoi":"10.21203/rs.3.rs-7917317/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7917317/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFemtosecond (fs) laser has emerged as an effective technique for nanojoining. However, the role of nanowire diameter and the associated electric field distribution under fs laser irradiation in nanojoint formation and polycrystalline evolution remains unclear. In this study, AgNW nanojoints were fabricated via fs laser irradiation, and the electric field intensity distribution was simulated using the three-dimensional finite-difference time-domain (FDTD) method. Nanojoint formation was examined across nanowires of different diameters under consistent laser processing conditions. High-resolution transmission electron microscopy (TEM) revealed that smaller-diameter nanowires (e.g., 60 nm) facilitate nanojoint formation with a relative joint cross-sectional area reaching 653%, significantly exceeding those of 200 nm (81%) and 300 nm (39%) nanowires. Moreover, regions with higher electric field intensity exhibited refined polycrystalline grains, with an average size of 4.62 nm at the nanojoint interface\u0026mdash;substantially smaller than that at non-bonded regions (16.38 nm and 36.14 nm). These findings provide new physical insights into the role of localized electromagnetic enhancement in joint morphology and grain structure regulation during fs laser nanojoining.\u003c/p\u003e","manuscriptTitle":"Diameter-dependent nanojoint formation and grain refinement in femtosecond laser nanojoining of AgNWs","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-28 16:33:18","doi":"10.21203/rs.3.rs-7917317/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-28T20:51:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-27T02:21:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-27T02:21:06+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-10-21T14:35:10+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"55770884-e456-4529-8f65-1616c97dbab1","owner":[],"postedDate":"October 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":56899484,"name":"Physical sciences/Materials science"},{"id":56899485,"name":"Physical sciences/Nanoscience and technology"},{"id":56899486,"name":"Physical sciences/Physics"}],"tags":[],"updatedAt":"2026-05-20T06:40:53+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-28 16:33:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7917317","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7917317","identity":"rs-7917317","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}