- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Ultraviolet Nanosecond Laser Annealing for Low Temperature 3D-Sequential Integration Gate Stack
摘要： For the top tier in a 3D sequential integration, we propose a low temperature gate first approach in which an in-situ doped amorphous silicon layer is deposited at 475°C then subsequently converted into a polycrystalline film using ultraviolet nanosecond laser annealing. We demonstrate the ability to obtain a low resistance poly-Si gate for the top transistors within a thermal budget expected to preserve the bottom devices electrical performance.
关键词： Ultraviolet Nanosecond Laser Annealing,Polycrystalline Silicon,3D-Sequential Integration,Low Temperature Gate Stack
更新于2025-09-16 10:30:52
-
Recrystallization and activation of ultra-high-dose phosphorus-implanted silicon using multi-pulse nanosecond laser annealing
摘要： Highly phosphorus-doped silicon source/drains are investigated to improve the performance of N-type metal-oxide-semiconductor field-effect transistors by decreasing their resistance and imparting strain to their channels. To find effective high temperature annealing for the activation of phosphorus in the source/drains, we apply single- and multi-pulse nanosecond laser annealing on highly phosphorus-doped silicon. The microstructure, strain, and electrical properties of highly phosphorus-doped silicon before and after laser annealing are analyzed. Our results demonstrate that the defects in both the recrystallized silicon and the end of range are decreased with 600 mJ cm?2 10-pulse annealing while considerable increase in phosphorus activation is achieved.
关键词： nanosecond laser annealing,strain engineering,activation,phosphorus-doped silicon,recrystallization
更新于2025-09-16 10:30:52
-
Nanosecond laser scribing for see‐through CIGS thin film solar cells
摘要： Building‐integrated photovoltaic (BIPV), especially in a semitransparent and/or see‐through configuration, has attracted significant attention because of the extended surfaces available for the photovoltaic (PV) installation including roofs, facades, and windows. In this study, we examine the P4 scribing process for fabricating see‐through cells on a new Cu (In,Ga)Se2 (CIGS) architecture with indium tin oxide (ITO) bottom contact, using a nanosecond laser beam of 532‐nm wavelength illuminated from glass substrate side. Through parametric studies with the variations of laser beam spot size and pulse energy, we have identified that enlarged laser beam with the pulse energy near scribing threshold could suppress both damage in ITO and electrical shunt induced by molten CIGS. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) analyses unveil that the molten CIGS mediated shunt mechanism, wetting the scribing edge and forming Cu‐rich metallic phase. The P4 scribing process operated near threshold fluence of enlarged laser beam clearly suppressed unwanted shunt, also minimizing the fluctuation in the desired film removal trend. Thermal analysis supports that enlarged laser beam enables scribing at reduced CIGS‐ITO interface temperature assisted by buckling‐based film delamination mechanism and also suppresses CIGS melting at scribing edge and its neighborhood. See‐through cells fabricated for the areal fraction of approximately 15% using the optimal laser scribing parameters exhibited the short circuit current reduction rate of 16.8% enabled by the low shunt resistance reduction rate of approximately 8%. Further studies are underway to elucidate precise shunt‐related scribing mechanism on the basis of the cross‐sectional analyses and time‐resolved diagnostics and to fabricate the module level see‐through PV architectures.
关键词： nanosecond laser,laser scribing,CIGS thin film solar cell,see‐through solar cell
更新于2025-09-12 10:27:22
-
Laser surface texturing of titanium with thermal post-processing for improved wettability properties
摘要： The use of lasers to create microstructures on metal surfaces in order to change the wettability properties a material has been widely explored, mainly using ultra-short pulsed lasers working in the femto and picosecond regime. In order to explore a more robust industrial method for the creation of super-hydrophobic surfaces, a fibre based nanosecond pulsed laser has been used to process polished Ti6Al4V samples to produce customised topography. The samples then received a low temperature annealing post-treatment. This, decrease the time needed for reaching the super-hydrophobic point considerably. The nanosecond pulsed laser provides a thermal component in the surface, helping with the creation of micro pillars in the surface morphology. The use of scanning electron microscopy (SEM) with energy dispersive X-Ray analysis (EDX), white light optical profiling, and contact angle measurements were used to characterize and quantify the effects of the surface modification on the wetting properties of the material.
关键词： laser surface texturing.,superhydrophobic,Nanosecond laser,thermal post-processing
更新于2025-09-12 10:27:22
-
Nanosecond laser ablation of the trapezoidal structures for turbomachinery applications
摘要： Correctly designed nature inspired micrometer size grooves i.e. riblets can be used to reduce drag. There exist several methods to manufacture these structures but all of them have their own problems and disadvantages, wherefore they are not perfectly suitable for all real industrial applications. Aim of this paper is to show how a short nanosecond pulse laser ablation can be applied in a micrometer size trapezoidal shape structures i.e. riblets manufacturing for a turbomachinery applications. It is shown that although the quality of the riblets, fabricated with this method, is not as good as with the best possible manufacturing methods, it is still enhancing the properties. Added to this, the processing speed is fast enough and acquisition costs of the system are economic so that method is suitable for the real industrial application. The wind tunnel studies indicate that the fabricated riblets on an airfoil reduce wall shear stress compared to a smooth airfoil without structuring.
关键词： micromachining,nanosecond laser,airfoil,riblet,microstructures,Laser ablation
更新于2025-09-12 10:27:22
-
Fabrication of surfaces with reduced friction using nanosecond laser
摘要： In this paper a short i.e. nanosecond pulse laser ablation is utilized to fabricate trapezoidal shaped microstructures i.e. riblets that are known to reduce friction. They can be applied for example in turbomachinery applications to make system more economical by reducing the wall shear stress on flow surfaces. Previously, these structures have been manufactured using different methods like grinding and ultrashort pulse lasers. The methods used before have their disadvantages and therefore they cannot be utilized in all applications. By using the nanosecond pulse laser instead of the shorter pulses, it is possible to manufacture riblets with a high fabrication speed and economically. Although a quality of the nanosecond pulse laser manufactured riblets is not as good as ones fabricated with the ultrashort pulse lasers, they are still able to reduce friction in the turbomachinery application.
关键词： micromachining,tubomachinery,nanosecond laser,airfoil,riblet,laser ablation,microstructures
更新于2025-09-12 10:27:22
-
Design and Fabrication of Dual-Scale Broadband Antireflective Structures on Metal Surfaces by Using Nanosecond and Femtosecond Lasers
摘要： Antire?ective surfaces, with their great potential applications, have attracted tremendous attention and have been the subject of extensive research in recent years. However, due to the signi?cant optical impedance mismatch between a metal surface and free space, it is still a challenging issue to realize ultralow re?ectance on a metal surface. To address this issue, we propose a two-step strategy for constructing antire?ective structures on a Ti-6Al-4V (TC4) surface using nanosecond and femtosecond pulsed lasers in combination. By controlling the parameters of the nanosecond laser, microgrooves are ?rst scratched on the TC4 surface to reduce the interface re?ection. Then, the femtosecond laser is focused onto the sample surface with orthogonal scanning to induce deep air holes and nanoscale structures, which e?ectively enhances the broadband absorption. The antire?ection mechanism of the dual-scale structures is discussed regarding morphological characterization and hemispherical re?ectance measurements. Finally, the modi?ed sample surface covered with micro-nano hybrid structures is characterized by an average re?ectance of 3.1% over the wavelengths ranging from 250 nm to 2250 nm.
关键词： nanosecond laser,broadband spectrum,femtosecond laser,micro-nano hybrid structures,antire?ective surfaces
更新于2025-09-12 10:27:22
-
Combination of Dual Wavelength Picosecond and Nanosecond Pulse Width Neodymium‐Doped Yttrium–Aluminum–Garnet Lasers for Tattoo Removal
摘要： Background and Objectives: Tattoo removal by laser has been mostly performed using Q‐switched laser, which has nanosecond pulse width. In recent years, the efficacy of treatment with picosecond pulse width laser has also been reported. Study Design/Materials and Methods: Using yttrium–aluminum–garnet laser with a potassium‐titanyl‐phosphate frequency‐doubling crystal, we performed a retrospective clinical study with combination treatment using pulse widths of 750 ps and 2 ns. The number of treatments was compared with the Kirby–Desai score. Tissue changes immediately after laser irradiation at 2 ns and 750 ps were compared using an electron microscope. Results: The combination treatment using pulse widths of 2 ns and 750 ps was safe and more effective than the Q‐switched neodymium‐doped yttrium–aluminum–garnet laser treatment. Tattoo removal was possible with significantly fewer treatment numbers than the Kirby–Desai score, without adverse events. The results from the scanning electron microscope revealed that ink particles irradiated by 750 ps were more dispersed than those by 2 ns. Conclusions: The combination treatment with pulse widths of 2 ns and 750 ps and 1064 nm and 532 nm wavelengths using the neodymium‐doped yttrium–aluminum–garnet laser was safe and effective and can be a useful option for tattoo removal.
关键词： tattoo removal,2 nanosecond,laser treatment,dual wavelength laser,750 picosecond
更新于2025-09-12 10:27:22
-
Effects of single- and multi-shape laser-textured surfaces on tribological properties under dry friction
摘要： Textural morphology is an important factor influencing dry friction, and few studies have been conducted regarding the effects of single- and multi-shape textures on dry tribological properties. In this work, six types of textures including single- and multi-shape textures were produced on 40Cr steel samples by using a nanosecond laser. Reciprocating sliding tests under dry friction were conducted using a pin-on-disc friction tester. The influences of textured surfaces with different textures on tribological properties were investigated. Results showed that tribological properties were affected by different textural morphologies. The dimple-textured surface had the highest friction coefficient, followed by the groove-textured surface. The sinusoidal-textured surface had the lowest friction coefficient. The friction coefficients of multi-shape textured surfaces were lower than those of non-textured surfaces but higher than those of sinusoidal-textured surfaces. The wear properties of the tested surfaces were consistent with the friction-coefficient results. The sinusoidal- and sinusoidal–groove-textured surfaces can be considered as the optimum choices for dry reciprocating friction.
关键词： textural morphology,dry friction,tribological properties,surface texturing,Nanosecond laser processing
更新于2025-09-12 10:27:22
-
From statistic to deterministic nanostructures in fused silica induced by nanosecond laser radiation
摘要： The production of structures by laser machining below the diffraction limit is still a challenge. However, self-organization processes can be useful. The laser-induced self-organized modification of the shape of photolithographic produced chromium structures on fused silica as well as the structuring of the fused silica surface by nanosecond UV laser radiation was studied, respectively. Low fluence single pulse laser irradiation (? > 300 mJ/cm2) cause the formation from chromium squares to droplets due to the mass transport in the molten chromium film. This process is governed by the instability of the molten metal due to the surface tension driven liquid phase mass transport. For a chromium pattern size similar to the instability length two specific droplet distributions were found which are single droplets with a determined position near the centre of the original pattern or random distributed smaller droplets arranged circularly. Each of the metal patterns can be transferred into the fused silica by a multi-pulse irradiation. The experimental results can be simulated well for low fluences by sequential solving the heat and Navier-Stokes equation.
关键词： fused silica,nanostructuring,nanosecond laser,IPSM-LIFE
更新于2025-09-12 10:27:22