- 标题
- 摘要
- 关键词
- 实验方案
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Ethanol-Precipitable Silica-Passivated Perovskite Nanocrystals Incorporated into Polystyrene Microspheres for Long-Term Storage and Re-Usage
摘要： Perovskite nanocrystals (PNCs) are emerging luminescent materials due to their fascinating physic-optical properties. However, their sensitive surface chemistry with organic polar solvents, oxygen and moisture greatly hinders their developments towards practical applications. Herein we promote silica-passivated PNCs (SP-PNCs) by in situ hydrolyzing the surface ligands of (3-aminopropyl) triethoxysilane. The resultant SP-PNCs possesses a high quantum yield (QY) of 80% and are precipitable by polar solvents, such as ethanol and acetone, without destroying their surface chemistry or losing QY, which offers an eco-friendly and efficient method for separation, purification and phase transfer of PNCs compared with the traditional solvent evaporation technique. Moreover, we further promoted a swelling-deswelling encapsulation process to incorporate the as-made SP-PNCs into polystyrene microspheres (PMs), which can largely increase the stability of the SP-PNCs against moisture for long-term storage. Besides, the embedded SP-PNCs can also be reused and mono-dispersed by totally dissolving the PMs in suitable solvents for making all-solution-processed devices. We thereby believe this work should open new avenues for greener synthesis, scalable production, and long-term storage of PNCs towards the emerging practical applications.
关键词： stability,perovskite nanocrystals,surface engineering,encapsulation,polar environment
更新于2025-09-23 15:23:52
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Surface engineering of a titanium alloy for tribological applications by nanosecond-pulsed laser
摘要： In many applications, surface engineering is needed in order to overcome the poor wear properties of titanium alloys. A fiber laser was used in different operation modes for remelting a Ti6Al4V surface and subsequently smoothing it again, resulting in a smooth, glossy and crack-free surface. The laser treated surface was characterized by tribological experiments, nanoindentation and (transmission) electron microscopy and compared to samples treated by plasma nitridation and thermal oxidation. All surface treatments improved the tribological behavior of Ti6Al4V to different extents. Nanoindentation measurements showed no strict correlation of mechanical properties and tribological behavior. It is hypothesized that apart from mechanical properties, binding of titanium electrons by interstitials plays a role in the occurrence or absence of adhesive wear.
关键词： Titanium alloys,Surface engineering,Adhesive wear,Ti6Al4V
更新于2025-09-23 15:21:01
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A Review: Crystal Growth for High-Performance All-inorganic Perovskite Solar Cells
摘要： Recently, halide perovskites have become one of the most promising materials for solar cells owing to their outstanding photoelectric performance. Among them, metal halide all-inorganic perovskites (CsPbX3; where X denotes a halogen) show superior thermal and light stability. In particular, the power conversion efficiency (PCE) of perovskite solar cells (pero-SCs) based on a CsPbX3 active layer has shown a steady increase from 2.7% to 19.03% with the improvement of the CsPbX3 crystal quality. In this review, we summarize methodologies that have been employed for controlling the growth of all-inorganic perovskite films so far, including precursor solution deposition, substrate modification, composition doping, and surface engineering. Furthermore, we discuss the effect of perovskite crystal characteristics on defects and perovskite film morphology, both of which are closely related to device performance. Finally, conclusions and perspectives are presented along with useful guidelines for developing all-inorganic pero-SCs with high PCE and robust stability.
关键词： light stability,halide perovskites,precursor solution deposition,all-inorganic perovskites,surface engineering,substrate modification,thermal stability,power conversion efficiency,CsPbX3,composition doping,solar cells,crystal growth
更新于2025-09-23 15:21:01
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The interaction between the osteosarcoma cell and stainless steel surface, modified by high-fluence, nanosecond laser pulses
摘要： The irradiation of metallic surfaces by high-fluence laser pulses in an oxygen-containing atmosphere inevitably modifies the surface topography, chemistry, and wettability. These modifications significantly influence cell-surface interactions and, consequently, surface biocompatibility. We investigate how surface texturing by high-fluence nanosecond laser pulses from a Nd:YAG laser (wavelength of 1064 nm) influences cell adhesion and morphology with the aim of assessing its impact on initial cell behaviour. Quantitative and qualitative analysis of osteosarcoma cell adhesion, viability, and cell morphology were evaluated after 24-hour exposure to non-treated and laser-textured stainless-steel (AISI 316L) surfaces by fluorescent and scanning electron microscopy. The results reveal that this, initial interaction between the cells and the laser-textured surfaces leads to round shaped cells with a smaller footprint. Contrarily, on the non-processed stainless-steel and control-glass surfaces the polygonal, highly elongated, and flattened cells are observed. The cells on the laser-textured surfaces are less dendritic, with short tubular protrusions and an overexpression of extracellular vesicles, which are rarely found on non-treated and control samples. This likely happens due to the formation of nanostructured, high-temperature oxides that are induced by laser ablation. The analysis by X-ray photoelectron spectroscopy reveals that the laser-textured stainless-steel surfaces contain Cr hexavalent oxide, which is more toxic than the native oxide layer on the non-processed samples.
关键词： MG63 cells,cell adhesion,Laser surface engineering,laser texturing,nanosecond-laser ablation
更新于2025-09-23 15:21:01
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Surface functionalization by nanosecond-laser texturing for controlling hydrodynamic cavitation dynamics
摘要： The interaction between liquid flow and solid boundary can result in cavitation formation when the local pressure drops below vaporization threshold. The cavitation dynamics does not depend only on basic geometry, but also on surface roughness, chemistry and wettability. From application point of view, controlling cavitation in fluid flows by surface functionalization is of great importance to avoid the unwanted effects of hydrodynamic cavitation (erosion, noise and vibrations). However, it could be also used for intensification of various physical and chemical processes. In this work, the surfaces of 10-mm stainless steel cylinders are laser textured in order to demonstrate how hydrodynamic cavitation behavior can be controlled by surface modification. The surface properties are modified by using a nanosecond (10–28 ns) fiber laser (wavelength of 1060 nm). In such a way, surfaces with different topographies and wettability were produced and tested in a cavitation tunnel at different cavitation numbers (1.0–2.6). Cavitation characteristics behind functionalized cylindrical surfaces were monitored simultaneously by high-speed visualization (20,000 fps) and high frequency pressure transducers. The results clearly show that cavitation characteristics differ significantly between different micro-structured surfaces. On some surfaces incipient cavitation is delayed and cavitation extent decreased in comparison with the reference – a highly polished cylinder. It is also shown that the increased surface wettability (i.e., hydrophilicity) delays the incipient cavitation.
关键词： Surface engineering,Laser texturing,Hydrodynamic cavitation,Fluid dynamics,Hydrophobic/hydrophilic surface
更新于2025-09-23 15:19:57
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Ethanol-Precipitable Silica-Passivated Perovskite Nanocrystals Incorporated into Polystyrene Microspheres for Long-Term Storage and Re-Usage
摘要： Perovskite nanocrystals (PNCs) are emerging luminescent materials due to their fascinating physic-optical properties. However, their sensitive surface chemistry with organic polar solvents, oxygen and moisture greatly hinders their developments towards practical applications. Herein we promote silica-passivated PNCs (SP-PNCs) by in situ hydrolyzing the surface ligands of (3-aminopropyl) triethoxysilane. The resultant SP-PNCs possesses a high quantum yield (QY) of 80% and are precipitable by polar solvents, such as ethanol and acetone, without destroying their surface chemistry or losing QY, which offers an eco-friendly and efficient method for separation, purification and phase transfer of PNCs compared with the traditional solvent evaporation technique. Moreover, we further promoted a swelling-deswelling encapsulation process to incorporate the as-made SP-PNCs into polystyrene microspheres (PMs), which can largely increase the stability of the SP-PNCs against moisture for long-term storage. Besides, the embedded SP-PNCs can also be reused and mono-dispersed by totally dissolving the PMs in suitable solvents for making all-solution-processed devices. We thereby believe this work should open new avenues for greener synthesis, scalable production, and long-term storage of PNCs towards the emerging practical applications.
关键词： surface engineering,polar environment,perovskite nanocrystals,encapsulation,stability
更新于2025-09-19 17:15:36
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Surface plasma Ag-decorated single-crystalline TiO2?x(B) nanorod/defect-rich g-C3N4 nanosheet ternary superstructure 3D heterojunctions as enhanced visible-light-driven photocatalyst
摘要： Ag-TiO2-x(B)/g-C3N4 ternary heterojunctions photocatalysts are fabricated by hydrothermal-calcination, photo-deposition procedure, and followed by in-situ solid-state chemical reduction procedure. As-obtained photocatalysts are consisted with heterojunctions between 2D g-C3N4 sheets and 1D TiO2(B) single-crystalline nanorods. The band gap of Ag-TiO2-x(B)/g-C3N4 ternary heterojunctions photocatalysts is reduced to ~2.23 eV due to plasma Ag and surface engineering. Under visible light irradiation, it has an optimal photocatalytic property for the reduction of Cr6+ (95%) and degradation of NH4+ (93%). The apparent reaction rate constants (k) of ternary heterojunctions photocatalysts for NH4+ and Cr6+ are 25 and 12 folds higher than that of original TiO2(B). Furthermore, Ag-TiO2-x(B)/g-C3N4 also has excellent hydrogen production efficiency, which is up to 410 mmol h-1 g-1. This enhancement can be attributed to the unique heterojunction formed by 1D single-crystalline TiO2(B) nanorods and 2D g-C3N4 sheets, surface plasma resonance effect of plasma Ag nanoparticle, and surface engineering. A possible photocatalytic mechanism is also proposed by analysizing the XPS valence-band spectra and the Mott-Schottky.
关键词： Surface engineering,g-C3N4 sheet,Visible-light-driven photocatalysis,Single-crystalline TiO2(B) nanorod,Heterojunction
更新于2025-09-19 17:15:36
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Ultra-fast laser-based surface engineering of conductive thin films
摘要： Modern electronics facilitate the need for fast, efficient, and reliable methods for direct laser-based surface engineering of conductive thin film materials on flexible substrates. Recent advances in pulsed laser source development only incrementally increased the processing speeds, as those are limited by the available scanning systems. Our goal was to combine a high pulse repetition frequency high-power pulse-on-demand fiber laser source with an ultra-fast resonant scanner to achieve high throughput surface engineering. The enabling factor to compensate a resonant scanner’s sinusoidal movement were the laser’s intrinsic pulse-on-demand capabilities beyond simple pulse picking solutions. The high temporal resolution at full laser power was exploited for spatially controlled surface texturing, allowing a minimally 3 μm positioning accuracy throughout the scanner’s range at up to 60 m/s scan speed with a 10 μm laser spot size. We applied the setup to processing of ITO and metallic films on flexible substrates for touchscreens, position sensors, or EM shielding. Surface modification and patterning of the conductive layer was successfully demonstrated while keeping the underlying surface intact. We employed a simple laser ablation model in comparison to the experimental data to improve the understanding of the ablation process. The resulting surface topography was observed and analysed.
关键词： ultra-fast laser processing,resonant scanning,intrinsic pulse-on-demand,surface engineering
更新于2025-09-12 10:27:22
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Toward Broadband Imaging: Surface Engineered PbS Quantum Dot/Perovskite Composite Integrated Ultrasensitive Photodetectors
摘要： PbS colloidal quantum dots (CQDs) passivated by thiocyanate anion (SCN-) are developed to combine with perovskite (CH3NH3PbI3) as building blocks for UV-vis-NIR broadband photodetectors. Both high electrical conductivity and appropriate energy level alignment are obtained by the in situ ligand exchange with SCN-. The PbS-SCN/CH3NH3PbI3 composite photodetectors are sensitive to a broad wavelength range covering the UV-vis-NIR region (365-1550 nm), possessing an excellent responsivity of 255 AW-1 at 365 nm and 1.58 AW-1 at 940 nm, remarkably high detectivity of 4.9×1013 Jones at 365 nm and 3.0×1011 Jones at 940 nm, and a fast response time ≤ 42 ms. Furthermore, a 10×10 photodetector array is fabricated and integrated, which constitutes a high-performance broadband image sensor. Our approach paves a way for the development of highly sensitive broadband photodetectors/imagers that can be easily integrated.
关键词： PbS colloidal quantum dot,surface engineering,perovskite,broadband imaging,photodetectors
更新于2025-09-12 10:27:22
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Nanowire Quantum Dot Surface Engineering for High Temperature Single Photon Emission
摘要： Generating single photons at high temperature remains a major challenge, particularly for group III-As and III-P materials widely used in optical communication. Here, we report a high temperature single photon emitter based on a “surface-free” GaAs quantum dot in a GaAsP nanowire. By using self-catalyzed vapor-liquid-solid growth and simple surface engineering, we can significantly enhance the optical signal from the QDs with a highly polarized photoluminescence at 750 nm. The “surface-free” nanowire quantum dots show photon antibunching up to 160 K and well resolved exciton lines as high as 220 K.
关键词： surface engineering,photon antibunching,quantum dot,single photon source,nanowire
更新于2025-09-12 10:27:22