94,379 results match your criteria silicon substrates

CKAP4 Antibody-Conjugated Si Quantum Dot Micelles for Targeted Imaging of Lung Cancer.

Nanoscale Res Lett 2021 Jul 31;16(1):124. Epub 2021 Jul 31.

Shanghai East Hospital, The Institute for Biomedical Engineering and Nano Science, Tongji University School of Medicine, Shanghai, 200120, China.

At present, various fluorescent nanomaterials have been designed and synthesized as optical contrast agents for surgical navigation. However, there have been no reports on the preparation of fluorescent contrast agents for lung cancer surgery navigation using silicon quantum dots (Si QDs). This study improved and modified the water-dispersible Si QD micelles reported by Pi et al. Read More

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Fe-Ni Alloy Nanoclusters Anchored on Carbon Aerogels as High-Efficiency Oxygen Electrocatalysts in Rechargeable Zn-Air Batteries.

Small 2021 Jul 30:e2102002. Epub 2021 Jul 30.

State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P. R. China.

In this work, Fe-Ni alloy nanoclusters (Fe-Ni ANCs) anchored on N, S co-doped carbon aerogel (Fe-Ni [email protected] catalysts) are successfully prepared by the optimal pyrolysis of polyaniline (PANI) aerogels derived from the freeze-drying of PANI hydrogel obtained by the polymerization of aniline monomers in the co-presence of tannic acid (TA), Fe , and Ni ions. In addition, the optimal molar ratio of the TA, Fe , and Ni ions for synthesis of Fe-Ni [email protected] catalysts are 1:2:5, which can guarantee the formation of carbon aerogel composed of quasi-2D porous carbon sheets and the formation of high-density Fe-Ni ANCs with an ultrasmall size between 2 to 2.8 nm. Read More

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Over 30% efficiency bifacial 4-terminal perovskite-heterojunction silicon tandem solar cells with spectral albedo.

Sci Rep 2021 Jul 30;11(1):15524. Epub 2021 Jul 30.

College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.

We developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. Read More

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Structural evidence for extracellular silica formation by diatoms.

Nat Commun 2021 Jul 30;12(1):4639. Epub 2021 Jul 30.

Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.

The silica cell wall of diatoms, a widespread group of unicellular microalgae, is an exquisite example for the ability of organisms to finely sculpt minerals under strict biological control. The prevailing paradigm for diatom silicification is that this is invariably an intracellular process, occurring inside specialized silica deposition vesicles that are responsible for silica precipitation and morphogenesis. Here, we study the formation of long silicified extensions that characterize many diatom species. Read More

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Unveiling structure-performance relationships from multi-scales in non-fullerene organic photovoltaics.

Nat Commun 2021 Jul 30;12(1):4627. Epub 2021 Jul 30.

State Key Laboratory of Silicon Materials, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, P. R. China.

Unveiling the correlations among molecular structures, morphological characteristics, macroscopic properties and device performances is crucial for developing better photovoltaic materials and achieving higher efficiencies. To achieve this goal, a comprehensive study is performed based on four state-of-the-art non-fullerene acceptors (NFAs), which allows to systematically examine the above-mentioned correlations from different scales. It's found that extending conjugation of NFA shows positive effects on charge separation promotion and non-radiative loss reduction, while asymmetric terminals can maximize benefits from both terminals. Read More

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Amorphous NiS and FeOOH as bifunctional co-catalysts for oxygen reduction and phenol (water) oxidation over BiVO under visible light.

J Hazard Mater 2021 Jul 21;421:126650. Epub 2021 Jul 21.

State Key Laboratory of Silicon Materials and Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China. Electronic address:

Monoclinic BiVO (BiV) has been widely used as a photoanode for water oxidation, but rarely as a photocatalyst for organic oxidation due to slow reaction of O. In this work, BiV has been modified with poorly crystallized sFe and sNi, where sFe is FeOOH, and sNi is a mixture of Ni(OH) and polysulfide. Under light, sFe/BiV and sNi/BiV in aqueous solution were more active than BiV, respectively, not only for phenol oxidation but also for O reduction. Read More

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Silicon-coupled tantalum pentoxide microresonators with broadband low thermo-optic coefficient.

Opt Lett 2021 Aug;46(15):3813-3816

Stable microresonators are important integrated photonics components but are difficult to achieve on silicon-on-insulator due to silicon intrinsic properties. In this work, we demonstrate broadband thermally stable tantalum pentoxide microresonators directly coupled to silicon waveguides using a micro-trench co-integration method. The method combines in-foundry silicon processing with a single step backend thin-film deposition. Read More

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Robust broadband athermal 2 × 2 Mach-Zehnder interferometer with sub-wavelength grating adiabatic couplers.

Opt Lett 2021 Aug;46(15):3781-3784

We report an all-silicon thermally insensitive (-1.5/) 2×2 Mach-Zehnder interferometer (MZI) over a spectral range from 1540 to 1620 nm. Additionally, the proposed MZI exhibits no imbalance in its extinction ratio with temperature. Read More

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Polymer-coated moth-eye hybrid structure for broadband antireflection in the terahertz region.

Opt Lett 2021 Aug;46(15):3761-3764

A hybrid antireflective structure (ARS) is proposed for enhancing the transmittance of terahertz (THz) waves. This hybrid ARS was made by attaching a polymer-based two-layer coating onto a moth-eye structure on a silicon (Si) substrate. The measured power reflectance of this hybrid ARS remained below 6% in the frequency range of 0. Read More

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Millimeter-long metamaterial surface-emitting antenna in the silicon photonics platform.

Opt Lett 2021 Aug;46(15):3733-3736

Integrated optical antennas are key components for on-chip light detection and ranging technology (LIDAR). In order to achieve a highly collimated far field with reduced beam divergence, antenna lengths on the order of several millimeters are required. In the high-index contrast silicon photonics platform, achieving such long antennas typically demands weakly modulated gratings with lithographic minimum feature sizes below 10 nm. Read More

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Anti-reflection subwavelength gratings for InP-based waveguide facets.

Opt Lett 2021 Aug;46(15):3701-3704

We demonstrate the anti-reflection properties of lithographically defined subwavelength gratings applied to the facets of integrated waveguides realized in the InP membrane-on-silicon platform. The subwavelength gratings are based on the gradient index effect to create a smooth index transition between the core material and air, making it possible to obtain reflections below -30 at a wavelength of 1550 nm for both TE and TM polarized modes, as shown by 3D finite-difference time-domain simulations. Characterizations performed using Mach-Zehnder interferometers as test structures show relative reflections as low as -25, confirming the effectiveness of the technique. Read More

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Laboratory X-ray interferometry imaging with a fan-shaped source grating.

Opt Lett 2021 Aug;46(15):3693-3696

The orientation mismatch between the cone beam of an X-ray tube and the grating lines in a flat substrate remains a big challenge for laboratory grating-based X-ray interferometry, since it severely limits the imaging field of view. Here, we fabricated fan-shaped source gratings by modulating the electric field during the deep reactive ion etching of silicon. The gold electroplated fan-shaped grating (3. Read More

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Compact dual-polarization silicon integrated couplers for multicore fibers.

Opt Lett 2021 Aug;46(15):3649-3652

Compact fiber-to-chip couplers play an important role in optical interconnections, especially in data centers. However, the development of couplers has been mostly limited to standard single-mode fibers, with few devices compatible with multicore and multimode fibers. Through the use of state-of-the-art optimization algorithms, we designed a compact dual-polarization coupler to interface chips and dense multicore fibers, demonstrating, for the first time, coupling to both polarizations of all the cores, with measured coupling efficiency of -4. Read More

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Temperature-dependent characteristics of GeSn/Ge multiple-quantum-well photoconductors on silicon.

Opt Lett 2021 Aug;46(15):3604-3607

Temperature-dependent characteristics of GeSn/Ge multiple-quantum-well (MQW) photoconductors (PCs) on silicon substrate were investigated. The high quality GeSn/Ge MQW epitaxial structure was grown on a silicon substrate using low temperature molecular beam epitaxy techniques with atomically precise thickness control. Surface-illuminated GeSn/Ge MQW PCs were fabricated using complementary metal-oxide-semiconductor-compatible processing and characterized in a wide temperature range of 55-320 K. Read More

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Fabrication of nanogap structures through spatially shaped femtosecond laser modification with the assistance of wet chemical etching.

Opt Lett 2021 Aug;46(15):3560-3563

Fabricating nanostructures with an extremely small feature size through a near-infrared femtosecond laser is a considerable challenge. In this Letter, we report a flexible, facile, and mask-free method that enables the formation of nanogap structures with a controllable size on silicon. This method involves spatially shaped femtosecond laser single-pulse modification assisted with chemical etching. Read More

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Characterizing ammonia emissions from water bodies using dynamic floating chambers.

Sci Total Environ 2021 Jul 10;796:148978. Epub 2021 Jul 10.

Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266200, Shandong, China; Sino-French Research Institute for Ecology and Environment (ISFREE), Shandong University, Qingdao 266200, Shandong, China. Electronic address:

Ammonia (NH) is the most important alkaline gas in the atmosphere and plays a central role in atmospheric pollution and the global N cycle. Water bodies receive increasing nitrogen inputs from effluents and atmospheric deposition due to anthropogenic activities and are regarded as the major natural NH and NH sinks. In this work, floating dynamic flux chambers were deployed at four types of freshwater (rivers, large reservoirs, medium-sized reservoirs and ponds) systems and a coastal seawater system to estimate the water-air NH emission fluxes. Read More

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Silicon-mediated growth promotion in maize (Zea mays L.) occurs via a mechanism that does not involve activation of the plasma membrane H-ATPase.

Plant Physiol Biochem 2021 Jul 16;166:1121-1130. Epub 2021 Jul 16.

Institute of Plant Nutrition (iFZ) Justus Liebig University Giessen, Heinrich Buff-Ring 26-32, 35392, Giessen, Germany.

Silicon (Si)-mediated growth promotion of various grasses is well documented. In the present study, Si-induced changes in maize shoot growth and its underlying mechanisms were studied. Maize plants were grown with various concentrations of Si (0-3 mM) in the nutrient solution. Read More

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Structural and Optical Properties of Textured Silicon Substrates by Three-Step Chemical Etching.

Langmuir 2021 Jul 30. Epub 2021 Jul 30.

Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.

We implemented the fabrication of hybrid structures, including pyramids, etching holes, and inverted pyramidal cavities on silicon substrates, by three-step chemical etching. To achieve this, we utilized anisotropic wet etching as the first-step etching to form pyramids of various sizes. Subsequently, metal-assisted chemical etching was performed to develop aligned etching holes on the pyramidal structure. Read More

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A General and Predictive Understanding of Thermal Transport from 1D- and 2D-Confined Nanostructures: Theory and Experiment.

ACS Nano 2021 Jul 30. Epub 2021 Jul 30.

Physics Department, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain.

Heat management is crucial in the design of nanoscale devices as the operating temperature determines their efficiency and lifetime. Past experimental and theoretical works exploring nanoscale heat transport in semiconductors addressed known deviations from Fourier's law modeling by including parameters, such as a size-dependent thermal conductivity. However, recent experiments have qualitatively shown behavior that cannot be modeled in this way. Read More

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Photon Upconversion for Photovoltaics and Photocatalysis: A Critical Review.

Chem Rev 2021 Jul 30. Epub 2021 Jul 30.

Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.

Opportunities for enhancing solar energy harvesting using photon upconversion are reviewed. The increasing prominence of bifacial solar cells is an enabling factor for the implementation of upconversion, however, when the realistic constraints of current best-performing silicon devices are considered, many challenges remain before silicon photovoltaics operating under nonconcentrated sunlight can be enhanced via lanthanide-based upconversion. A photophysical model reveals that >1-2 orders of magnitude increase in the intermediate state lifetime, energy transfer rate, or generation rate would be needed before such solar upconversion could start to become efficient. Read More

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Recurrent Auricular Pseudocyst: Successful Treatment Using a Dental Silicon Cast.

Case Rep Dermatol 2021 May-Aug;13(2):352-355. Epub 2021 Jul 9.

Department of Dermatology, Kameda Medical Center, Chiba, Japan.

Auricular pseudocysts (APs) are benign intercartilaginous cysts at the auricle. Various therapeutic options have been used to treat APs, but they frequently recur in usual clinical practice. Here, we report a case of AP successfully treated using a silicon cast. Read More

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Recording Strategies for High Channel Count, Densely Spaced Microelectrode Arrays.

Front Neurosci 2021 13;15:681085. Epub 2021 Jul 13.

Institute of Microelectronics of Seville (IMSE-Centro Nacional de Microelectrónica), Spanish National Research Council, Seville, Spain.

Neuroscience research into how complex brain functions are implemented at an extra-cellular level requires neural recording interfaces, including microelectrodes and read-out circuitry, with increased observability and spatial resolution. The trend in neural recording interfaces toward employing high-channel-count probes or 2D microelectrodes arrays with densely spaced recording sites for recording large neuronal populations makes it harder to save on resources. The low-noise, low-power requirement specifications of the analog front-end usually requires large silicon occupation, making the problem even more challenging. Read More

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Progressive growth of the solid-electrolyte interphase towards the Si anode interior causes capacity fading.

Nat Nanotechnol 2021 Jul 29. Epub 2021 Jul 29.

Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA.

The solid-electrolyte interphase (SEI), a layer formed on the electrode surface, is essential for electrochemical reactions in batteries and critically governs the battery stability. Active materials, especially those with extremely high energy density, such as silicon (Si), often inevitably undergo a large volume swing upon ion insertion and extraction, raising a critical question as to how the SEI interactively responds to and evolves with the material and consequently controls the cycling stability of the battery. Here, by integrating sensitive elemental tomography, an advanced algorithm and cryogenic scanning transmission electron microscopy, we unveil, in three dimensions, a correlated structural and chemical evolution of Si and SEI. Read More

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Modeling the optical properties of twisted bilayer photonic crystals.

Light Sci Appl 2021 Jul 29;10(1):157. Epub 2021 Jul 29.

School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.

We demonstrate a photonic analog of twisted bilayer graphene that has ultra-flat photonic bands and exhibits extreme slow-light behavior. Our twisted bilayer photonic device, which has an operating wavelength in the C-band of the telecom window, uses two crystalline silicon photonic crystal slabs separated by a methyl methacrylate tunneling layer. We numerically determine the magic angle using a finite-element method and the corresponding photonic band structure, which exhibits a flat band over the entire Brillouin zone. Read More

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Uncovering recent progress in nanostructured light-emitters for information and communication technologies.

Light Sci Appl 2021 Jul 29;10(1):156. Epub 2021 Jul 29.

LTCI, Institut Polytechnique de Paris, Télécom Paris, 19 place Marguerite Perey, 91120, Palaiseau, France.

Semiconductor nanostructures with low dimensionality like quantum dots and quantum dashes are one of the best attractive and heuristic solutions for achieving high performance photonic devices. When one or more spatial dimensions of the nanocrystal approach the de Broglie wavelength, nanoscale size effects create a spatial quantization of carriers leading to a complete discretization of energy levels along with additional quantum phenomena like entangled-photon generation or squeezed states of light among others. This article reviews our recent findings and prospects on nanostructure based light emitters where active region is made with quantum-dot and quantum-dash nanostructures. Read More

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Combined Bottom-Up and Top-Down Approach for Highly Ordered One-Dimensional Composite Nanostructures for Spin Insulatronics.

ACS Appl Mater Interfaces 2021 Jul 29. Epub 2021 Jul 29.

Department of Materials Science and Engineering, Uppsala University, Box 35, Uppsala SE-751 03, Sweden.

Engineering magnetic proximity effects-based devices requires developing efficient magnetic insulators. In particular, insulators, where magnetic phases show dramatic changes in texture on the nanometric level, could allow us to tune the proximity-induced exchange splitting at such distances. In this paper, we report the fabrication and characterization of highly ordered two-dimensional arrays of LaFeO (LFO)-CoFeO (CFO) biphasic magnetic nanowires, grown on silicon substrates using a unique combination of bottom-up and top-down synthesis approaches. Read More

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Effect of biochar produced from sewage sludge on tomato (Solanum lycopersicum L.) growth, soil chemical properties and heavy metal concentrations.

J Environ Manage 2021 Jul 26;297:113325. Epub 2021 Jul 26.

School of Environmental Engineering, Technical University of Crete, Chania, 73100, Greece. Electronic address:

The addition of biochar, as shown in the literature, improves significantly the chemical and physical soil properties and plant growth. This study examined the effect of biochar, compost and the combination of them on growth, nutrient and heavy metal concentrations of tomato. Biochar (BC) was produced from sewage sludge by pyrolysis at the temperature of 300 °C. Read More

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CuCoOx/BiVO multifunctional catalyst for organics degradation, water oxidation, and O reduction under visible light.

J Hazard Mater 2021 Jun 29;419:126515. Epub 2021 Jun 29.

State Key Laboratory of Silicon Materials and Department of Chemistry, Zhejiang University, Hangzhou 310027, China. Electronic address:

Monoclinic BiVO (BiV) is an excellent photoanode for water oxidation, but it is a poor photocatalyst for organic oxidation due to slow O reduction. Herein we report a 94-fold increased photocatalytic activity of BiV through a surface deposited CuCoOx. The model reaction was phenol degradation in aqueous solution under visible light. Read More

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Antimicrobial Properties of Food Nanopackaging: A New Focus on Foodborne Pathogens.

Front Microbiol 2021 12;12:690706. Epub 2021 Jul 12.

Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran.

Food products contaminated by foodborne pathogens (bacteria, parasites, and viruses) cause foodborne diseases. Today, great efforts are being allocated to the development of novel and effective agents against food pathogenic microorganisms. These efforts even might have a possible future effect in coronavirus disease 2019 (COVID-19) pandemic. Read More

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