Syntheses and applications of small metallic nanorods from solution and physical vapor deposition

2013 ◽  
Vol 2 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Stephen P. Stagon ◽  
Hanchen Huang
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Vacuum ◽  
Scientific Understanding ◽  
Oriented Attachment ◽  
Cubic Metals ◽  
Wide Range ◽  
Common Face ◽  
Metallic Nanorods ◽  
Nanorod Growth

AbstractMetallic nanorods have a wide range of important technological applications. Fabrication of metallic nanorods of ~100 nm using physical vapor deposition (PVD) has been commonplace for several decades. On this length scale, nanorods have similar functionalities to bulk thin films with the advantage of increased surface area. When the lateral dimension is decreased to ~10 nm new functionalities emerge that are not present in thin film counterparts, such as catalysis. Small metallic nanorods, those ~10 nm, have classically been made through solution-based synthesis. Alternatively, recent advances in scientific understanding, a framework of nanorod growth, have opened the door to the fabrication of small nanorods through PVD. Growing small nanorods through PVD offers technologically relevant advantages over solution-based processing like direct control of aspect ratio, pure high-vacuum processing, and oriented attachment to a substrate. Among materials, gold (Au) has a wide range of technological applications and is a good prototype for understanding the behavior of common face center cubic metals. This article reviews solution processing and PVD of small metallic nanorods using Au as a prototype, in terms of scientific understanding and fabrication knowledge, and further compares and contrasts the two approaches.

Temperature-induced chaos during nanorod growth by physical vapor deposition

2009 ◽  
Vol 105 (9) ◽  
pp. 094318 ◽  
Author(s):  
S. Mukherjee ◽  
C. M. Zhou ◽  
D. Gall
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Nanorod Growth

Optical Thin Films of Metal Oxides Produced by the Sol-Gel Method for Photovoltaic Applications

2019 ◽  
Vol 293 ◽  
pp. 83-95
Author(s):  
Marek Szindler
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Light Transmission ◽  
Sol Gel ◽  
Thin Layers ◽  
Gel Method ◽  
Sol Gel Method ◽  
Wide Range

The use of thin films in optoelectronic and photovoltaic devices is aimed at improving the physical properties of the substrate material. The modification of the surface of the silicon substrate is thus one of the greatest challenges in research on photovoltaic materials, in order to achieve even greater efficiency or better adapt their properties depending on the application. The technologies of applying layers vary depending on the effect to be obtained and the material from which the layer is formed. In practice, the most common method is chemical vapor deposition and physical vapor deposition, and the most commonly applied optical materials are SiO2, TiO2 and Si3N4.This paper presents the results of investigations on morphology and optical properties of the prepared aluminium oxide thin films. Thin films were prepared with use of sol-gel spin coating method. Surface morphology studies were carried out using an atomic force microscope. To characterize the surface of the thin films, 3D images and histograms of the frequency of individual inequalities were made. In order to characterize the optical properties of Al2O3 thin films, the reflectance and light transmission tests were performed using a spectrophotometer. Optical constants were determined using a spectroscopic ellipsometer. Results and their analysis show that the sol-gel method allows the deposition of homogenous thin films of Al2O3 with the desired geometric characteristics and good optical properties. Uniform, continuous thin layers with a roughness not exceeding a few nanometres were deposited. Their deposition enabled to reduce the reflection of light from the polished substrate below 15% in a wide range (425-800nm) while maintaining high transparencies (over 90%). The obtained results causes that mentioned thin films are good potential material for optics, optoelectronics and photovoltaics.

Combinatorial Studies for High Density Si and Ge Nanoparticle Arrays

2006 ◽  
Vol 933 ◽  
Author(s):  
Scott K. Stanley ◽  
John G. Ekerdt
Keyword(s):  
Vapor Deposition ◽  
Entire Range ◽  
Physical Vapor Deposition ◽  
Large Temperature ◽  
Nanoparticle Arrays ◽  
Nanoparticle Growth ◽  
Wide Range ◽  
Time Required ◽  
Nanoparticle Sizes ◽  
Deposition Conditions

ABSTRACTA simple combinatorial approach for studying chemical and physical vapor deposition (CVD and PVD) nanoparticle growth is presented utilizing temperature and precursor flux gradients across sample surfaces. Large temperature gradients (450-700 °C) are induced covering the entire range of interest for most CVD and PVD processes. Precursor flux gradients may also be introduced simultaneously or separately using a tungsten cracking filament mounted on a translation arm. Theory and calibration experiments are explained and results from a study on Ge nanoparticle growth on HfO2 surfaces are presented and analyzed. This method drastically decreases experimental time required to investigate nanoparticle growth and identify optimum deposition conditions. Furthermore, this approach greatly facilitates preparation of library samples containing a wide range (several orders of magnitude) in variation of nanoparticle sizes, density, and composition for subsequent studies.

Ionic Distribution in Plasma for the Process of Electron-Beam Physical Vapor Deposition

2014 ◽  
Vol 597 ◽  
pp. 153-156
Author(s):  
Ching Yen Ho ◽  
Wen Chieh Wu
Keyword(s):  
Electron Beam ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Radial Direction ◽  
State Equations ◽  
Ion Density ◽  
Ionic Distribution ◽  
Coating Efficiency ◽  
Wide Range ◽  
Coating Method

This paper investigates ionic distribution generated by electron beam (EB) during Physical Vapor Deposition (PVD). EB-PVD has a wide range of applications in thermal barrier coatings (TBCs) due to favorable characteristics compared with other coating processes. EB-PVD is an important material coating method that utilizes electron beams as heat sources to evaporate materials, which are then deposited on a substrate. Therefore EB-induced ionic distribution dominates the quality and thickness of the final coating on the substrate. Assuming the EB-generated plasma to be only a function of radial direction, the steady-state equations of continuity and motion combined with Posson’s equation were utilized to analyze the plasma distributions along the radial direction. The available experimental data are also used to validate the model. The results show that the coating efficiency can be improved by decreasing the ratio of the electron thermal energy to the initial ion energy and increasing the ratio of the initial ion density to the initial electron density. The uniformity of coating can be achieved by reducing the initial ion density.

New Copper wide range nanosensor electrode prepared by physical vapor deposition at oblique angles for the non-enzimatic determination of glucose

2015 ◽  
Vol 169 ◽  
pp. 195-201 ◽  
Author(s):  
Pedro Salazar ◽  
Victor Rico ◽  
Rafael Rodríguez-Amaro ◽  
Juan P. Espinós ◽  
Agustín R. González-Elipe
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Wide Range

scholarly journals Smallest Metallic Nanorods Using Physical Vapor Deposition

2013 ◽  
Vol 110 (13) ◽  
Author(s):  
Xiaobin Niu ◽  
Stephen P. Stagon ◽  
Hanchen Huang ◽  
J. Kevin Baldwin ◽  
Amit Misra
Keyword(s):  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Metallic Nanorods

Uses of Physical Vapor Deposition Processes in Photoelectrochemical Water Splitting Systems

2016 ◽  
Vol 3 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Pedro Migowski ◽  
Adriano F. Feil
Keyword(s):  
Water Splitting ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Low Cost ◽  
High Vacuum ◽  
Thin Layers ◽  
Photoelectrochemical Cells ◽  
Gas Source ◽  
Deposition Processes ◽  
Semiconducting Electrode

AbstractMost of the hydrogen on planet earth is found bound to oxygen atoms in water, making H2O one of the most promising H2 storage molecules. Large availability, non-toxicity and low cost are among the advantages of using H2O as a H2 gas source. However, the decomposition of water into H2 and O2, called water splitting, needs a large amount of energy, increasing the final cost per kg of hydrogen produced. In this context, the energy provided by the sun may be used to power photoelectrochemical cells (PEC) for water splitting to produce cheap and high purity H2. This mini-review will show recent advances on the use of physical vapor deposition (PVD) methods to improve semiconducting electrode performance. PVD enables the preparation of thin layers of expensive materials over photoelectrodes, therefore decreasing PEC systems manufacture costs. Moreover, the interface of between the semiconductor and the evaporated materials can be optimized under high vacuum conditions used in PVD processes and more efficient PEC systems can be obtained.

High Knudsen Number Physical Vapor Deposition: Predicting Deposition Rates and Uniformity

2006 ◽  
Vol 129 (11) ◽  
pp. 1546-1553 ◽  
Author(s):  
Chetan P. Malhotra ◽  
Roop L. Mahajan ◽  
W. S. Sampath
Keyword(s):  
Finite Element ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Vacuum ◽  
Thickness Variation ◽  
Molecular Flow ◽  
Vacuum Deposition ◽  
Deposition Rates ◽  
Finite Element Software ◽  
Deposition Processes

The problem of predicting deposition rates and film thickness variation is relevant to many high-vacuum physical vapor deposition (PVD) processes. Analytical methods for modeling the molecular flow fail when the geometry is more complicated than simple tubular or planar sources. Monte Carlo methods, which have traditionally been used for modeling PVD processes in more complicated geometries, being probabilistic in nature, entail long computation times, and thus render geometry optimization for deposition uniformity a difficult task. Free molecular flow is governed by the same line-of-sight considerations as thermal radiation. Though the existence of an analogy between the two was recognized by Knudsen (1909, Ann. Phys., 4(28), pp. 75–130) during his early experiments, it has not been exploited toward mainstream analysis of deposition processes. With the availability of commercial finite element software having advanced geometry modelers and built-in cavity radiation solvers, the analysis of diffuse thermal radiation problems has become considerably simplified. Hence, it is proposed to use the geometry modeling and radiation analysis capabilities of commercial finite element software toward analyzing and optimizing high-vacuum deposition processes by applying the radiation-molecular flow analogy. In this paper, we lay down this analogy and use the commercial finite element software ABAQUS for predicting radiation flux profiles from planar as well as tube sources. These profiles are compared to corresponding deposition profiles presented in thin-film literature. In order to test the ability of the analogy in predicting absolute values of molecular flow rates, ABAQUS was also employed for calculating the radiative flux through a long tube. The predictions are compared to Knudsen’s analytical formula for free molecular flow through long tubes. Finally, in order to see the efficacy of using the analogy in modeling the film thickness variation in a complex source-substrate configuration, an experiment was conducted where chromium films were deposited on an asymmetric arrangement of glass slides in a high-vacuum PVD chamber. The thickness of the deposited films was measured and the source-substrate configuration was simulated in ABAQUS. The variation of radiation fluxes from the simulation was compared to variation of the measured film thicknesses across the slides. The close agreement between the predictions and experimental data establishes the feasibility of using commercial finite element software for analyzing high vacuum deposition processes.

Polymer Assisted Deposition (PAD) of thin metal films: A new technique to the preparation of metal oxides and reduced metal films

2005 ◽  
Vol 893 ◽  
Author(s):  
Piyush Shukla ◽  
Yuan Lin ◽  
Edel M Minogue ◽  
Anthony K Burrell ◽  
T Mark McCleskey ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Sol Gel ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Metal Films ◽  
Metal Thin Films ◽  
Solution Methods ◽  
A New Technique

AbstractCurrently, there are a variety of techniques to deposit metal thin films ranging from high vacuum techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), through to solution methods like sol-gel. While the vacuum techniques can be limited by size and cost, sol-gel can be limited be the availability of appropriate precursors. All of these techniques have the further limitation that they cannot be used to coat porous materials conformally.Polymer assisted deposition (PAD) addresses some of the limitations of sol-gel and costs of high vacuum techniques. PAD utilizes an aqueous polymer to bind a metal or metal complex that serves both to encapsulate the metal to prevent chemical reaction and maintain an even distribution of the metal in solution. Another advantage that PAD has is that the same solution can be used as precursors for the growth of metal oxide or reduced metal films. Herein, we report on the utility of PAD in preparing metal oxide films used to conformally coat porous material and reduced metal films.

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