Ordered Layered Assemblies of Nanoparticles

MRS Bulletin ◽  
2001 ◽  
Vol 26 (12) ◽  
pp. 992-997 ◽  
Author(s):  
Nicholas A. Kotov
Keyword(s):  
Thin Films ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Inorganic Nanoparticles ◽  
Advanced Materials ◽  
Layer By Layer ◽  
Magnetic Devices ◽  
Lbl Assembly ◽  
Wide Range ◽  
Spatial Dimensions

The development of advanced materials from inorganic nanoparticles (NPs) is currently one of the most dynamic areas of science. NPs are attracting significant fundamental and commercial interest, with a wide range of applications including the next generation of optics, electronics, and sensors. In optical, electrical, and magnetic devices, NPs will be mostly used in the form of thin films. Currently, such films are typically made by the spincoating, spraying, or sometimes simple painting of nanoparticle–matrix mixtures. Layer-by-layer (LBL) assembly is one of the new methods of thin-film deposition, often realized as sequentially adsorbed (mono)layers of oppositely charged polyelectrolytes. LBL assembly has also been successfully applied to thin films of NPs and nanocolloids, that is, dispersed species with only one or two spatial dimensions in the nanoscale regime.

scholarly journals Special Issue: Current Research in Thin Film Deposition: Applications, Theory, Processing, and Characterisation

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1228
Author(s):  
Ross Birney
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Special Issue ◽  
Wide Range

Today, thin films are near-ubiquitous and are utilised in a very wide range of industrially and scientifically important areas [...]

A computational study of SrTiO3 thin film deposition: Morphology and growth modes

2009 ◽  
Vol 24 (6) ◽  
pp. 1994-2000 ◽  
Author(s):  
Jennifer L. Wohlwend ◽  
Cosima N. Boswell ◽  
Simon R. Phillpot ◽  
Susan B. Sinnott
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Computational Study ◽  
Thin Film Deposition ◽  
Layer Growth ◽  
Film Deposition ◽  
Layer By Layer ◽  
Growth Modes ◽  
Deposition Processes ◽  
Dynamics Simulations

The growth of SrTiO3 (STO) thin films is examined using classical molecular dynamics simulations. First, a beam of alternating SrO and TiO2 molecules is deposited on the (001) surface of STO with incident kinetic energies of 0.1, 0.5, or 1.0 eV/atom. Second, deposition of alternating SrO and TiO2 monolayers, where both have incident energies of 1.0 eV/atom, is examined. The resulting thin film morphologies predicted by the simulations are compared to available experimental data. The simulations indicate the way in which the incident energy, surface termination, and beam composition influence the morphology of the thin films. On the whole, some layer-by-layer growth is predicted to occur on both SrO- and TiO2-terminated STO for both types of deposition processes, with the alternating monolayer approach yielding thin films with compositions that are much closer to that of bulk STO.

A General Route to Nanoparticle Thin Films and Coatings

2005 ◽  
Vol 901 ◽  
Author(s):  
Bratindranath Mukherjee ◽  
Ravishankar Narayanan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Microstructural Characterization ◽  
Thin Film Deposition ◽  
Basic Mechanism ◽  
Film Deposition ◽  
Magnetic Storage ◽  
Sers Substrate ◽  
Large Area ◽  
Wide Range

AbstractNanoparticles thin films have wide range of applications such as nanoelectronics, magnetic storage devices, SERS substrate fabrication, optical grating and antireflective coating. Present work describes a method to prepare large area nanoparticles thin film of the order of few square centimeters. Thin film deposition has been done successfully on a wide range of conducting as well as non conducting substrates such as carbon-coated copper grid, silicon, m-plane of alumina, glass and (100) plane of NaCl single crystal. SEM, TEM and AFM studies have been done for microstructural characterization of the thin films. A basic mechanism has been proposed towards the understanding of the deposition process.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

scholarly journals Progresses on the Use of Two-Photon Absorption Laser Induced Fluorescence (TALIF) Diagnostics for Measuring Absolute Atomic Densities in Plasmas and Flames

Plasma ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 145-171
Author(s):  
Kristaq Gazeli ◽  
Guillaume Lombardi ◽  
Xavier Aubert ◽  
Corinne Y. Duluard ◽  
Swaminathan Prasanna ◽  
...  
Keyword(s):  
Optical Transition ◽  
Thin Film Deposition ◽  
Laser Induced Fluorescence ◽  
Film Deposition ◽  
Stimulated Emission ◽  
Photon Absorption ◽  
Collisional Quenching ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Wide Range

Recent developments in plasma science and technology have opened new areas of research both for fundamental purposes (e.g., description of key physical phenomena involved in laboratory plasmas) and novel applications (material synthesis, microelectronics, thin film deposition, biomedicine, environment, flow control, to name a few). With the increasing availability of advanced optical diagnostics (fast framing imaging, gas flow visualization, emission/absorption spectroscopy, etc.), a better understanding of the physicochemical processes taking place in different electrical discharges has been achieved. In this direction, the implementation of fast (ns) and ultrafast (ps and fs) lasers has been essential for the precise determination of the electron density and temperature, the axial and radial gradients of electric fields, the gas temperature, and the absolute density of ground-state reactive atoms and molecules in non-equilibrium plasmas. For those species, the use of laser-based spectroscopy has led to their in situ quantification with high temporal and spatial resolution, with excellent sensitivity. The present review is dedicated to the advances of two-photon absorption laser induced fluorescence (TALIF) techniques for the measurement of reactive species densities (particularly atoms such as N, H and O) in a wide range of pressures in plasmas and flames. The requirements for the appropriate implementation of TALIF techniques as well as their fundamental principles are presented based on representative published works. The limitations on the density determination imposed by different factors are also discussed. These may refer to the increasing pressure of the probed medium (leading to a significant collisional quenching of excited states), and other issues originating in the high instantaneous power density of the lasers used (such as photodissociation, amplified stimulated emission, and photoionization, resulting to the saturation of the optical transition of interest).

Phenethylammonium bismuth halides: from single crystals to bulky-organic cation promoted thin-film deposition for potential optoelectronic applications

2019 ◽  
Vol 7 (36) ◽  
pp. 20733-20741 ◽  
Author(s):  
Mehri Ghasemi ◽  
Miaoqiang Lyu ◽  
Md Roknuzzaman ◽  
Jung-Ho Yun ◽  
Mengmeng Hao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Single Crystals ◽  
Organic Cation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Optoelectronic Applications ◽  
Excellent Stability

The phenethylammonium cation significantly promotes the formation of fully-covered thin-films of hybrid bismuth organohalides with low surface roughness and excellent stability.

INK JET PRINTED THIN FILMS ON GLASS AND POLYIMIDE SUBSTRATES

2013 ◽  
Vol 37 (3) ◽  
pp. 873-883 ◽  
Author(s):  
Tsai-Cheng Li ◽  
Rwei-Ching Chang ◽  
Yen-Choung Li
Keyword(s):  
Thin Films ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Electric Resistance ◽  
Ink Jet Printing ◽  
Sputtered Films ◽  
Ink Jet ◽  
Jet Printing ◽  
Conductive Thin Films

Silver conductive thin films deposited on glass and polyimide substrates by using ink jet printing are studied in this work. Characterization of the printed thin films and comparison with sputtered films are investigated. The micro texture, residual stress, adhesion, hardness, optical reflectance, and electric resistance of the thin films are discussed. The result shows that the ink jet printing has the possibility to replace sputtering in thin film deposition, especially for the polymer substrates.

scholarly journals METAL COMPLEX TETRAIZOINDOLES AS SENSOR MATERIALS

2002 ◽  
Vol 10 (11) ◽  
pp. 79-87
Author(s):  
Cornel Tarabasanu Mihaila ◽  
Lavinia G. Hinescu ◽  
Cristian Boscornea ◽  
Carmen Moldovan ◽  
Mihai E. Hinescu
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Molecular Weight ◽  
Metal Complex ◽  
Electrical Response ◽  
Average Molecular Weight ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Oxide Semiconductor ◽  
Synthesis Methods

The paper presents the synthetic routes for obtaining some organic semiconductors and their characterization in order to use in thin film deposition for gas sensing devices. An original technique was used to control the molecular weight of polymeric phthalocyanine. We have fabricated devices consisting of evaporated thin films of copper, nickel, and iron phthalocyanines onto interdigital electrodes and estimated the electrical conductivity by in-situ measurements. The films were evaporated onto substrates (gold or aluminum) which were entirely integrated in the standard CMOS (capacitor metal oxide semiconductor) technology. The objectives of this work were to improve the synthesis methods of organic metal-complex tetraizoindoles and their polymers and to evaluate their electrical response and thermal stability as evaporated thin films. We have also investigated the variation of polymers conductivity and sublimation yield with the average molecular weight. We found that for polymeric phthalocyanines, the thermal stability was higher than for Pcs monomers. The stability of polymers increased with the average molecular weight.

scholarly journals Structural Stability of Magnetic Tunnel Junction Based Molecular Spintronics Devices (MTJMSD)

2020 ◽  
Author(s):  
Joshua Dillard ◽  
Uzma Amir ◽  
Pawan Tyagi ◽  
Vincent Lamberti
Keyword(s):  
Thin Films ◽  
Structural Stability ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Molecular Devices ◽  
Metal Electrodes ◽  
Molecular Spintronics ◽  
Ferromagnetic Electrodes

Abstract Harnessing the exotic properties of molecular level nanostructures to produce novel sensors, metamaterials, and futuristic computer devices can be technologically transformative. In addition, connecting the molecular nanostructures to ferromagnetic electrodes bring the unprecedented opportunity of making spin property based molecular devices. We have demonstrated that magnetic tunnel junction based molecular spintronics device (MTJMSD) approach to address numerous technological hurdles that have been inhibiting this field for decades (P. Tyagi, J. Mater. Chem., Vol. 21, 4733). MTJMSD approach is based on producing a capacitor like a testbed where two metal electrodes are separated by an ultrathin insulator and subsequently bridging the molecule nanostructure across the insulator to transform a capacitor into a molecular device. Our prior work showed that MTJMSDs produced extremely intriguing phenomenon such as room temperature current suppression by six orders, spin photovoltaic effect, and evolution of new forms of magnetic metamaterials arising due to the interaction of the magnetic a molecule with two ferromagnetic thin films. However, making robust and reproducible electrical connections with exotic molecules with ferromagnetic electrodes is full of challenges and requires attention to MTJMSD structural stability. This paper focuses on MTJMSD stability by describing the overall fabrication protocol and the associated potential threat to reliability. MTJMSD is based on microfabrication methods such as (a) photolithography for patterning the ferromagnetic electrodes, (b) sputtering of metallic thin films and insulator, and (c) at the end electrochemical process for bridging the molecules between two ferromagnetic films separated by ∼ 2nm insulating gap. For the successful MTJMSD fabrication, the selection of ferromagnetic metal electrodes and thickness was found to be a deterministic factor in designing the photolithography, thin film deposition strategy, and molecular bridging process. We mainly used isotropic NiFe soft magnetic material and anisotropic Cobalt (Co) with significant magnetic hardness. We found Co was susceptible to chemical etching when directly exposed to photoresist developer and aged molecular solution. However, NiFe was very stable against the chemicals we used in the MTJMSD fabrication. As compared to NiFe, the Co films with > 10nm thickness were susceptible to mechanical stress-induced nanoscale deformities. However, cobalt was essential to produce (a) low leakage current before transforming the capacitor from the magnetic tunnel junction into molecular devices and (b) tailoring the magnetic properties of the ferromagnetic electrodes. This paper describes our overall MTJMSD fabrication scheme and process optimization to overcome various challenges to produce stable and reliable MTJMSDs. We also discuss the role of mechanical stresses arising during the sputtering of the ultrathin insulator and how to overcome that challenge by optimizing the insulator growth process. This paper will benefit researchers striving to make nanoscale spintronics devices for solving grand challenges in developing advanced sensors, magnetic metamaterials, and computer devices.

Chemical Bath Deposition of Lead Sulphide (PbS) Thin Film and their Characterization

2013 ◽  
Vol 209 ◽  
pp. 111-115 ◽  
Author(s):  
Sandip V. Bhatt ◽  
M.P. Deshpande ◽  
Bindiya H. Soni ◽  
Nitya Garg ◽  
Sunil H. Chaki
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Raman Spectroscopy ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Excitation Wavelength ◽  
Face Centered Cubic ◽  
Phonon Modes ◽  
Lead Sulphide ◽  
X Ray

Thin film deposition of PbS is conveniently carried out by chemical reactions of lead acetate with thiourea at room temperature. Energy dispersive analysis of X-ray (EDAX), X-ray diffraction (XRD), selected area electron diffraction patterns (SAED), UV-Vis-NIR spectrophotometer, Scanning Electron Microscopy (SEM), Atomic force microscopy (AFM), Photoluminescence (PL) and Raman spectroscopy techniques are used for characterizing thin films. EDAX spectra shows that no impurity is present and XRD pattern indicates face centered cubic structure of PbS thin films. The average crystallite size obtained using XRD is about 15nm calculated using Scherrer’s formula and that determined from Hall-Williamson plot was found to be 18nm. SAED patterns indicate that the deposited PbS thin films are polycrystalline in nature. Blue shift due to quantum confinement was seen from the UV-Vis-NIR absorption spectra of thin film in comparison with bulk PbS. The Photoluminescence spectra obtained for thin film with different excitation sources shows sharp emission peaks at 395nm and its intensity of photoluminescence increases with increasing the excitation wavelength. Raman spectroscopy of deposited thin film was used to study the optical phonon modes at an excitation wavelength of 488nm using (Ar+) laser beam.

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