Article
Chemistry, Physical
Philip Harder, Andreas Nielsen, Ann-Katrin Sassnau, Dennis Bonatz, Markus Perbandt, Tobias Kipp, Alf Mews
Summary: The study investigates the structural properties of CdS, CdSe, and CdTe semiconductor nanowires grown by the SLS method through a detailed experimental and simulation approach. The different samples show varying fractions of Wurtzite and Zincblende, as determined by high-resolution TEM and p-XRD analysis of selected wires and a large amount of NWs.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Thomas Kanne, Dags Olsteins, Mikelis Marnauza, Alexandros Vekris, Juan Carlos Estrada Saldana, Sara Loric, Rasmus D. Schlosser, Daniel Ross, Szabolcs Csonka, Kasper Grove-Rasmussen, Jesper Nygard
Summary: The core platform of several recent quantum device proposals relies on parallel 1D semiconductor channels connected by a superconducting strip, utilizing Andreev processes or topological effects. A strategy for synthesizing double InAs nanowires using III-V molecular beam epitaxy is presented, allowing for the deposition of a superconducting layer onto nanowires without breaking the vacuum in order to ensure pristine interfaces between the superconductor and the semiconductor nanowires. The method demonstrates the utility of high yield merged or separate parallel nanowires with full or half-shell superconductor coatings in complex quantum devices through electron transport measurements.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Mikelis Marnauza, Robin Sjokvist, Sebastian Lehmann, Kimberly A. A. Dick
Summary: Environmental transmission electron microscopy is used to study the growth of Au nanoparticle seeded GaSb nanowires in situ. It is found that the precursor V/III ratio affects the morphology, composition, and diameter of the nanowires. The observed trends can be reproduced in a conventional exsitu system, highlighting the transferability and importance of the results obtained in situ.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Physics, Applied
Martin Kosicek, Oleg Baranov, Janez Zavasnik, Uros Cvelbar
Summary: In this study, we investigate the temperature limitations for the growth of copper oxide nanowires through thermal oxidation of copper, which has been a long-standing puzzle for scientists. By gradually lowering the oxidation temperature and using electron microscopy techniques, we determine the lowest temperature at which nanowire growth is observed and the smallest nanowire diameter achievable. Our experimental results are supported by theoretical modeling, providing insights into the nucleation processes of nanowires. The temperature dependence of the critical nucleus size governs the limiting diameter of the nanowires.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Pengfei Hu, Dong Zhou, Shiqing Xu, Qianru Ma, Jiaqi Yin, Yali Cao, Jing Xu
Summary: This study successfully achieved room-temperature aqueous phase- and size-controlled synthesis of CdS nanocrystals by modulating the pH value and using chelator ethylenediamine for guiding the assembly of nanocrystals.
Article
Engineering, Chemical
Weiting Yu, Dezheng Yang, Rendan Zhu, Luzhen Liu, Yan Yu, Juntao Tang, Zhiqiao He, Jiexu Ye, Shuang Song
Summary: In this study, a catalyst with high activity and stability was successfully prepared by functionalizing the surface of the electrode with 2,6-diaminopyridine for photoassisted electrochemical CO2 reduction toward CO. The proposed synergistic mechanism facilitates the reduction of CO2 to produce CO and inhibits the competitive hydrogen evolution reaction.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Weiting Yu, Dezheng Yang, Rendan Zhu, Luzhen Liu, Yan Yu, Juntao Tang, Zhiqiao He, Jiexu Ye, Shuang Song
Summary: In this study, 2,6-diaminopyridine (2,6-DAP) was used for the first time to functionalize the electrode surface, resulting in a p-Si/Ag/2,6-DAP electrode with high activity and CO selectivity. The optimized potential for CO production was found to be -0.9 V vs RHE, with a Faradaic efficiency of 84.56%. A synergistic mechanism involving the reduction of CO2 by Ag and the adsorption of CO2 by 2,6-DAP was proposed to explain the enhanced catalytic performance of p-Si/Ag/2,6-DAP.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Giorgos Boras, Xuezhe Yu, H. Aruni Fonseka, George Davis, Anton V. Velichko, James A. Gott, Haotian Zeng, Shiyao Wu, Patrick Parkinson, Xiulai Xu, David Mowbray, Ana M. Sanchez, Huiyun Liu
Summary: Self-catalyzed AlGaAs nanowires and AlGaAs/GaAs nanowires with quantum dots were successfully grown on Si substrates, showing strong room temperature photoluminescence and potential for applications in nanolasers and single-photon sources. The structural studies revealed the self-formation of an Al-rich AlGaAs shell with wide alloy fluctuations, while individual nanowires exhibited clear quantum dot behavior with spatially localized emission and narrow exciton line width.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Abdul Mateen, Ghulam Farid, Kui-Qing Peng
Summary: This study systematically analyzed the influence of temperature on the fabrication of zigzag silicon nanowires using metal-assisted chemical etching. The results showed that zigzag-shaped silicon nanowires can be fabricated at low temperatures in the presence of glycerol, while straight silicon nanowires are obtained at higher temperatures.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Sudhakar Sivakumar, Axel R. Persson, Wondwosen Metaferia, Magnus Heurlin, Reine Wallenberg, Lars Samuelson, Knut Deppert, Jonas Johansson, Martin H. Magnusson
Summary: Aerotaxy is presented as a scalable alternative technology for producing quality semiconductor nanowires at a high growth rate. By using size-controlled Au seed particles and organometallic precursors, Aerotaxy can produce nanowires with perfect crystallinity and controllable dimensions to meet industrial production requirements. Experimental observations and validation through computational flow dynamics (CFD) approach are used to better understand the Aerotaxy growth model.
Article
Crystallography
Pham Hong Thach, Tran Van Khai
Summary: This study synthesized ZnO nanowires and explored the relationship between their optical properties and gas-sensing performance. The results showed that the ZnO nanowires have excellent crystalline quality and good optical properties, and can detect NO2 gas at low concentrations.
Article
Nanoscience & Nanotechnology
Zhijun Wang, Ge He, Huazhou Zhang, Che Liao, Chi Yang
Summary: This study synthesized Pb2BiS2I3 nanowires using a hot-injection solution approach and investigated their application in photodetectors. The results showed that Pb2BiS2I3 nanowires had a narrow size distribution, excellent stability, and strong absorption in the visible-light region. The photodetector based on Pb2BiS2I3 nanowires exhibited excellent stability and photoresponse under different wavelengths of visible-light irradiation.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Behrouz Behdani, Jacob Lumpkins, Carlos A. Silvera A. Batista
Summary: The objective of this article is to investigate the effect of electric polarizability on the propulsion and collective dynamics of metallodielectric Janus particles. Janus particles with sequential layers of titanium and SiO2 were fabricated to create model systems. The study found that the propulsion velocity spectra closely matched the electrorotation spectra, indicating a relationship between the two. The results also showed that the propulsion velocity reflects the real part of the particles' polarizability, and the thickness of the metal cap affects their behavior.
Article
Materials Science, Multidisciplinary
Haiguo Hu, Yonghong Zeng, Shan Gao, Rui Wang, Jinlai Zhao, Kaixi You, Yufeng Song, Quanlan Xiao, Rui Cao, Jianqing Li, Zhitao Lin, Jia Guo, Yiqing Shu, Zhinan Guo, Dianyuan Fan
Summary: A unique and rapid solution method has been proposed for the synthesis of high-quality hexagonal Te nanosheets, which showed excellent optical absorption, good photoresponse, and stability as a photoanode material in a photoelectrochemical photodetector. Additionally, the Te nanosheets demonstrated excellent nonlinear absorption properties and successfully achieved mode-locking operation in a erbium-doped fiber ring laser.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Optics
Maoji Wang, Lauren R. Richey-Simonsen, Jordan M. Gerton
Summary: To investigate the optical modes in nanophotonic devices, researchers demonstrated a probe-free, far-field method to characterize the optical modes within GaN nanowires, observing spectral signatures resulting from lateral leakage of waveguide modes. By using an analytical model coupled with finite element simulations, they were able to accurately deduce the transverse dimension of the nanowires from hyperspectral images.
Article
Physics, Applied
Victor Calero, Raul Fernandez-Mateo, Hywel Morgan, Pablo Garcia-Sanchez, Antonio Ramos
Summary: This work investigates the stationary electro-osmotic flow vortices induced by ac electric fields around dielectric micropillars in electrolytes, known as concentration-polarization electro-osmosis (CPEO). The theoretical predictions and experimental data support the existence and characteristics of these flows, which differ significantly from previous theories based on induced-charge electro-osmosis. These findings not only advance our understanding of ac field effects on fluid flows but also have potential implications for flow control in microfluidic systems.
PHYSICAL REVIEW APPLIED
(2021)
Article
Biochemical Research Methods
Raul Fernandez-Mateo, Pablo Garcia-Sanchez, Victor Calero, Antonio Ramos, Hywel Morgan
Summary: An improved method for determining the electroosmotic mobility and zeta potential of surfaces based on a current-monitoring method has been described. This technique eliminates the need for measurements of channel dimensions and sample conductivities, leading to a simple high precision measurement of the zeta potential of PDMS surfaces.
Article
Chemistry, Physical
A. M. Boymelgreen, G. Kunti, P. Garcia-Sanchez, A. Ramos, G. Yossifon, T. Miloh
Summary: The study investigates the interaction between active particles and walls to explain discrepancies between experiments and theory. The findings show that the motion direction and frequency dispersion of particles can be controlled by the interaction between ICEP and sDEP. Proximity to walls enhances this interaction and has a significant impact on particle mobility.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Physics, Multidisciplinary
Raul Fernandez-Mateo, Victor Calero, Hywel Morgan, Pablo Garcia-Sanchez, Antonio Ramos
Summary: This article presents the phenomenon and causes of particle-wall repulsion during electrophoresis, highlighting the quadrupolar electro-osmotic flows in low-frequency electric fields as the cause of particle-wall interaction. It emphasizes the importance of considering this hydrodynamic wall repulsion in the design and application of microfluidic devices.
PHYSICAL REVIEW LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Raul Fernandez-Mateo, Victor Calero, Pablo Garcia-Sanchez, Antonio Ramos, Hywel Morgan
Summary: We present a user-friendly, open source software for detecting and counting single particles in a continuous-flow system. The software automatically processes video images of particles, including pre-conditioning and size-based discrimination for fluorescent and non-fluorescent particles of different sizes. It allows real-time quality control of the video files and provides concentration distribution of the particles in the fluid flow direction. This versatile tool is suitable for a wide range of microfluidic applications and does not require expertise in image analysis.
MICROFLUIDICS AND NANOFLUIDICS
(2023)
Article
Mechanics
Raul Fernandez-Mateo, Hywel Morgan, Antonio Ramos, Pablo Garcia-Sanchez
Summary: We experimentally investigate the repulsion between charged microscopic particles and the channel walls during electrophoresis in microfluidic devices. This repulsion is primarily caused by hydrodynamic interactions arising from flow vortices induced by the slip velocity on the particle surface due to the electric field. Measurement of wall-particle separation allows us to infer the maximum slip velocity on the particle surface, including very small velocities that are otherwise difficult to directly measure. The data at low electric field amplitudes agree with theoretical predictions based on Concentration Polarization Electro-osmosis (CPEO), but the predictions of CPEO theory break down for higher electric fields. Furthermore, we show that strong electric fields can disrupt the quadrupolar flow structures, leading to a weaker wall repulsion.
Article
Chemistry, Analytical
Jose Eladio Flores-Mena, Pablo Garcia-Sanchez, Antonio Ramos
Summary: In this study, we investigate the scattering of metal colloids by an insulating circular post under the influence of an alternating current (AC) electric field. We analyze the effects of electrical forces such as induced dipole-repulsion, induced-charge electroosmotic (ICEO) flow, and dielectrophoresis on the particles. The relative influence of these forces is examined in relation to the frequency of the AC field, particle size, and distance to the post. Numerical simulations are performed to model the scattering of metal colloids in a microchannel with an insulating circular post under alternating current electric fields. The simulation results show that the maximum particle deviation occurs when the applied electric field is parallel to the flow direction, and this deviation is more significant at low electric field frequencies where the ICEO interaction dominates over other mechanisms.
Article
Biochemical Research Methods
Victor Calero, Raul Fernandez-Mateo, Hywel Morgan, Pablo Garcia-Sanchez, Antonio Ramos
Summary: Deterministic Lateral Displacement (DLD) utilizes periodic arrays of pillars to sort micro and nano particles with high precision in microfluidic channels. This article presents a detailed numerical analysis of particle motion in a DLD micropillar array under low-frequency AC electric field. The study reveals that a combination of Electrophoresis (EP) and Concentration-Polarization Electroosmosis (CPEO) driven wall-particle repulsion explains the observed experimental behavior of particles.
JOURNAL OF CHROMATOGRAPHY A
(2023)
Article
Mechanics
Israel Gabay, Vesna Bacheva, Dotan Ilssar, Moran Bercovici, Antonio Ramos, Amir Gat
Summary: The use of thin liquid films has expanded into various applications beyond lubrication and coatings. This study focuses on a non-self-adjoint problem arising from finite liquid films with impermeable boundary conditions. A combined theoretical and experimental approach is employed to provide a time-dependent closed-form analytical solution for this system. The results show that confined films exhibit different behavior compared to infinite or periodic films, impacting their deformation and response time.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Israel Gabay, Federico Paratore, Evgeniy Boyko, Antonio Ramos, Amir D. Gat, Moran Bercovici
Summary: In this study, a theoretical model and experimental demonstration of thin liquid film deformations induced by a dielectric force distribution established by surface electrodes are presented. The coupling of this force with the Young-Laplace equation successfully predicts the deformation of the interface, with experimental validation showing good agreement with the model. A designed experimental set-up allows for the production of complex deformations on liquid films, showcasing the potential for dynamic modulation and polymerization of the films.
