Fullerene C60–Silver Nanoparticles Hybrid Structures: Optical and Photoelectric Characterization

2008 ◽  
Vol 8 (11) ◽  
pp. 5958-5965 ◽  
Author(s):  
N. L. Dmitruk ◽  
O. Yu. Borkovskaya ◽  
S. V. Mamykin ◽  
D. O. Naumenko ◽  
N. I. Berezovska ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Absorption Coefficient ◽  
Internal Quantum Efficiency ◽  
Barrier Properties ◽  
Light Transmittance ◽  
Silicon Substrates ◽  
Photoelectric Properties ◽  
Current Voltage ◽  
Si Films

A detailed optical and photoelectric characterization of pristine fullerene C60 films deposited onto n-silicon substrates (C60/Si), C60 films crosslinked by means of the solvent-free chemical functionalization with 1,8-diaminooctane (C60-DA/Si), and the pristine and crosslinked films decorated with silver nanoparticles (C60-Ag/Si and C60-DA-Ag/Si), was carried out. The reflectance spectra obtained allowed to calculate the absorption coefficient (α = 4pik/λ) spectral dependencies and the spectra of light transmittance in layered barrier structures metal(Au)/fullerene/Si. Photoelectric properties of the films were investigated as well. The experimentally measured values of band gap were in a good agreement with mobility gap values (2.3±0.1 eV). The decoration of fullerene films (both pristine and chemically crosslinked) with silver nanoparticles did not change the photocurrent spectra as compared to those for undecorated fullerene films, but lowered the values of internal quantum efficiency Qint. The photocurrent generated in fullerene/Si heterostructure, showed a maximum value at λ ∼450 nm (Qint max≈0.25 for decorated and undecorated C60-DA/Si films), and it was higher for the samples based on pristine C60 films, in accordance with their higher absorption coefficient. Diminishing of Qint for C60-DA/Si and C60-DA-Ag/Si films was observed for the spectral range of photocurrent generated in Si layer. The analysis of dark current–voltage characteristics showed that the barrier properties differ insignificantly, though a certain increase of series resistance was observed for the C60-DA/Si samples.

The Processing and Characterization of Hybrid Silica-Based Xerogel Films

1997 ◽  
Vol 476 ◽  
Author(s):  
Loren A. Chow ◽  
Ted Yu ◽  
Bruce S. Dunn ◽  
K. N. Tu ◽  
Chien Chiang
Keyword(s):  
Dielectric Constant ◽  
Breakdown Field ◽  
Silicon Substrates ◽  
Porous Thin Films ◽  
Hybrid Silica ◽  
Current Voltage ◽  
Volatile Organic ◽  
Substrate Moisture ◽  
Xerogel Films

AbstractHybrid organic-inorganic xerogel films were deposited as porous thin films by spinning the precursor sol on silicon substrates. Films of various compositions were prepared using combinations of the following precursors: methyltrimethoxysilane, dimethoxydimethylsilane and tetramethoxysilane (TMOS). The hybrid films exhibited excellent gap-filling capabilities (0.45 micron trenches). Thermal desorption experiments indicate that heating to ∼130 C removes moisture and volatile organic constituents present in the as-cast film. Curing was found to increase the adhesion between the xerogel and the silicon substrate. Moisture was found to be responsible for an increase in the dielectric constant. That is, in ambient, the dielectric constant for a cured film was found to be 4.4; but in a dry atmosphere, it decreased to 2.5. Current-voltage measurements show the cured hybrid film possesses a breakdown field of 3.4 MV/cm.

Characterization of Thin PtSI/p-Si Schottky Diodes

1985 ◽  
Vol 54 ◽  
Author(s):  
J. Silverman ◽  
P. Pellegrini ◽  
J. Comer ◽  
A. Golvbovic ◽  
M. Weeks ◽  
...  
Keyword(s):  
Schottky Diodes ◽  
Electrical Current ◽  
Processing Parameters ◽  
Silicon Substrates ◽  
Unexpected Result ◽  
State Diffusion ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
P Type

ABSTRACTA series of PtSi on p-type Si diodes have been characterized in order to establish correlations among processing parameters, metallurgical features and electrical properties. Characterization techniques include analytical (TED, TEM), electrical (current-voltage characteristics), and optical (photoemission and absorption). The fabrication techniques involve e-beam evaporation of platinum layers at UHV levels onto VLSI grade (100) p-type silicon substrates. The silicide layers are formed via sub-eutectic solid state diffusion at 350°C. The main trends with thickness as well as possible interrelationships are described. An unexpected result is the presence of unreacted polycrystalline Pt and Pt2Si at the interface.

Electron Energy Analysis of Germanium and Silica Layers on Silicon Substrates

1975 ◽  
Vol 33 ◽  
pp. 96-97
Author(s):  
R. W. Ditchfield ◽  
A. G. Cullis
Keyword(s):  
Epitaxial Growth ◽  
Electron Energy ◽  
Silicon Substrates ◽  
Secondary Phases ◽  
Si Substrates ◽  
Transmission Electron ◽  
Layer Structures ◽  
Si Films ◽  
Electron Energy Loss ◽  
Growth Centres

An energy analyzing transmission electron microscope of the Möllenstedt type was used to measure the electron energy loss spectra given by various layer structures to a spatial resolution of 100Å. The technique is an important, method of microanalysis and has been used to identify secondary phases in alloys and impurity particles incorporated into epitaxial Si films.Layers Formed by the Epitaxial Growth of Ge on Si Substrates Following studies of the epitaxial growth of Ge on (111) Si substrates by vacuum evaporation, it was important to investigate the possible mixing of these two elements in the grown layers. These layers consisted of separate growth centres which were often triangular and oriented in the same sense, as shown in Fig. 1.

Characterization of Y-Ba-Cu-O films grown on silicon substrates by sequential evaporation

1988 ◽  
Vol 46 ◽  
pp. 866-867
Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
L. G. Turner ◽  
N. Lewis
Keyword(s):  
Thin Film ◽  
Thin Film Deposition ◽  
Superconducting Films ◽  
Electron Beam Evaporation ◽  
Film Deposition ◽  
Silicon Substrates ◽  
Superconducting Properties ◽  
Sequential Electron ◽  
Thin Superconducting Films

There is great interest in the growth of thin superconducting films of YBa2Cu3Ox on silicon, since this is a necessary first step in the use of this superconductor in a variety of possible electronic applications including interconnects and hybrid semiconductor/superconductor devices. However, initial experiments in this area showed that drastic interdiffusion of Si into the superconductor occurred during annealing if the Y-Ba-Cu-O was deposited direcdy on Si or SiO2, and this interdiffusion destroyed the superconducting properties. This paper describes the results of the use of a zirconia buffer layer as a diffusion barrier in the growth of thin YBa2Cu3Ox films on Si. A more complete description of the growth and characterization of these films will be published elsewhere.Thin film deposition was carried out by sequential electron beam evaporation in vacuum onto clean or oxidized single crystal Si wafers. The first layer evaporated was 0.4 μm of zirconia.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Synthesis and Characterization of Silver Nanoplates by a Seed-mediated Method

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Trisodium Citrate ◽  
Synthesis And Characterization ◽  
Silver Nanoplates ◽  
Seed Mediated

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.

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