Effects of Amorphous Carbon Films on the Performance of Porous Silicon Electroluminescence

2002 ◽  
Vol 737 ◽  
Author(s):  
Bernard Gelloz ◽  
Nobuyoshi Koshida
Keyword(s):  
Porous Silicon ◽  
Amorphous Carbon ◽  
Chemical Stability ◽  
Indium Tin Oxide ◽  
Carbon Film ◽  
Carbon Films ◽  
Positive Effects ◽  
Thin Carbon ◽  
Thin Carbon Film ◽  
The Stability

ABSTRACTEfficient electroluminescence (EL) is obtained at low operating voltages (<3 V) from n+-type silicon- electrochemically oxidized thin nanocrystalline porous silicon (PS)-amorphous carbon-Indium tin oxide (ITO) junctions. The effects of a few nanometer thick amorphous carbon film between PS and ITO on the EL characteristics have been investigated. The carbon film enhances the stability. The EL efficiency is improved due to a reduction of current density and an increase in EL intensity. In addition, the reproducibility from device to device is very much improved by the carbon film. The enhancement in stability should originate from the capping of PS by the carbon film and the high chemical stability of carbon and Si-C bonds, which should prevent PS oxidation. The carbon film acts as an efficient buffer layer between PS and ITO, resulting in enhanced mechanical, electrical and chemical stability of the top contact and providing high reproducibility. The thin carbon film has only positive effects on all the EL characteristics. This is a very important step towards application.

A New Method for Single Atom Specimen Preparation

1975 ◽  
Vol 33 ◽  
pp. 224-225
Author(s):  
W. Chiu ◽  
R. M. Glaeser ◽  
S. Prussin
Keyword(s):  
Unit Area ◽  
Carbon Film ◽  
Gold Atom ◽  
High Resolution Electron Microscopy ◽  
Carbon Films ◽  
Single Atom ◽  
Specimen Preparation ◽  
Electron Microscopic ◽  
Thin Carbon ◽  
Thin Carbon Film

A reliable method of confirming that one is able to produce single atom images in high resolution electron microscopy is to make a comparison of the number of atoms per unit area that is seen by the electron microscopic observations and the number per unit area as determined by a separate experimental technique of high accuracy. This report presents a method of preparinga specimen composed of a low distribution of gold atoms (ca. 1 atom/104 Å2) sandwiched between two ultra-thin carbon films, and also a method of measuring the gold atom density in the specimen by neutron activation analysis.The specimen was prepared by evaporation onto a freshly cleaved mica substrate in a vacuum evaporator, as shown in Figure 1. One side of the vacuum chamber was used to prepare a thin carbon film according to the method of Williams and Glaeser (1972), and the other side was used to evaporate the gold atoms from a molybdenum strip, which had a micro-quantity of gold deposited on a 1 cm2 surface area from a previous evaporation.

Thin Carbon Film Areas Produced under Controlled Conditions

1973 ◽  
Vol 31 ◽  
pp. 78-79
Author(s):  
Nabil Rizk ◽  
Irwin Bendet
Keyword(s):  
Electron Microscopy ◽  
Carbon Film ◽  
High Resolution Electron Microscopy ◽  
Carbon Films ◽  
The Other ◽  
Biological Macromolecules ◽  
Resolution Electron ◽  
Thin Carbon ◽  
Carbon Substrates ◽  
Thin Carbon Film

The need for increasingly thin films to attain the ultimate in high resolution electron microscopy has seen the development of carbon substrates for the support of biological macromolecules. To date, the procedures employed for producing such substrates have involved either the floating off of carbon films from mica onto water and picking them up on EM grids or the deposition of carbon upon plastic covered grids, the plastic of which is subsequently dissolved away. We have now developed an efficient technique, unencumbered by the difficulties associated with the other procedures, for producing well delineated areas of thin carbon film of measurable thickness. In this procedure we utilize silk threads, about 15 microns in diameter, stretched across an adjustable frame having a 1” square opening (Fig. 1).

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Alkaline Dissociation Products of Lumbricus Terrestris Hemoglobin Viewed with the STEM

1981 ◽  
Vol 39 ◽  
pp. 434-435
Author(s):  
O. H. Kapp ◽  
M. Ohtsuki ◽  
N. Robin ◽  
S. N. Vinogradov ◽  
A. V. Crewe
Keyword(s):  
Carbon Film ◽  
Lumbricus Terrestris ◽  
Uranyl Acetate ◽  
Acetate Solution ◽  
Oxygen Carriers ◽  
Complex Molecules ◽  
Thin Carbon ◽  
Thin Carbon Film ◽  
Multiple Copies ◽  
Hill Coefficients

Annelid extracellular hemoglobins are among the largest known proteins (M.W = 3.9 x 106), and together with the hemocyanins are the largest known oxygen carriers. They display oxygen affinities generally higher than those o vertebrate hemoglobins with Hill coefficients ranging from slightly higher than unity to values as high as 5-6. These complex molecules are composed of multiple copies of as many as six different polypeptides and posse: approximately 150 hemes per molecule.The samples were diluted to 100-200 μg/ml with distilled water just before application to a thin carbon film (∽15 Å thick). One percent (w/v) uranyl acetate solution was used for negative staining for 2 minutes and dried in air. The specimens were examined with the high resolution STEM. Their general appearance is that of a hexagonal bilayer (Fig. 1), each layer consisting of six spheroidal subunits. The corner to corner hexagonal dimensic is approximately 300 Å and the bilayer thickness approximately 200 Å.

The stability of nitrogen-containing amorphous carbon films after annealing at moderate temperatures

1998 ◽  
Vol 7 (2-5) ◽  
pp. 495-498 ◽  
Author(s):  
A.P. Burden ◽  
E. Mendoza ◽  
S.R.P. Silva ◽  
G.A.J. Amaratunga
Keyword(s):  
Amorphous Carbon ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
The Stability

Structural Analysis of Boron- and Nitrogen-Doped Amorphous Carbon Films from Bio-Product

2020 ◽  
Vol 860 ◽  
pp. 190-195
Author(s):  
Irma Septi Ardiani ◽  
Khoirotun Nadiyyah ◽  
Anna Zakiyatul Laila ◽  
Sarayut Tunmee ◽  
Hideki Nakajima ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Amorphous Carbon ◽  
Carbon Film ◽  
Carbon Films ◽  
Basic Material ◽  
Carbon Phase ◽  
Amorphous Carbon Film ◽  
Amorphous Carbon Films ◽  
Nitrogen Doped ◽  
P Type

Amorphous carbon films have been explored and used in a wide variety of applications. With the n-type and p-type amorphous carbon film, it can be used to make p-n junctions for solar cells. This research aims to study the structure of boron- and nitrogen-doped amorphous carbon (a-C:B and a-C:N) films. This research uses the basic material of bio-product from palmyra sugar to form amorphous carbon. Amorphous carbon was synthesized by heating the palmyra sugar at 250°C. The results of XRD showed that the doped films produce an amorphous carbon phase. PES was used to analyze the bonding state of dopants in the sample. B4C, BC3, and BC2O bonds formed in a-C:B, while pyridine and pyrrolic formed in a-C:N.

Density Measurement of Thin Sputtered Carbon Films

1988 ◽  
Vol 32 ◽  
pp. 323-330 ◽  
Author(s):  
G. L. Gorman ◽  
M.-M. Chen ◽  
G. Castillo ◽  
R. C. C. Perera
Keyword(s):  
Carbon Film ◽  
Processing Condition ◽  
Density Measurement ◽  
Practical Interest ◽  
Processing Parameters ◽  
Carbon Films ◽  
Nondestructive Method ◽  
Gas Pressure ◽  
X Ray ◽  
Thin Carbon

AbstractThe densities of sputtered thin carbon films have been determined using a novel X-ray technique. This nondestructive method involves the measurement of the transmitivity of a characteristic soft (low energy) X-ray line through the carbon film, and using the established equation I1 = I0eμpt where I1/I0 is the transmitivity, fi the photo absorption cross section, t the independently measured thickness, the density p can be easily solved for. This paper demonstrates the feasibility of using this simple technique to measure densities of carbon films as thin as 300 Å, which is of tremendous practical interest as carbon films on this order of thickness are used extensively as abrasive and corrosive barriers (overcoats) for metallic recording media disks. The dependence of the density upon film thickness for a fixed processing condition is presented, as also its dependence (for a fixed thickness) upon different processing parameters (e.g., sputtering gas pressure and target power). The trends noted in this study indicate that the sputtering gas pressure plays the most important role, changing the film density from 2.4gm/cm3 at 1 mTorr to 1.5gm/cm3 at 30 mTorr for 1000 Å thick films.

Thin carbon film deposition using energetic ions of a dense plasma focus

1997 ◽  
Vol 226 (3-4) ◽  
pp. 212-216 ◽  
Author(s):  
Chhaya R. Kant ◽  
M.P. Srivastava ◽  
R.S. Rawat
Keyword(s):  
Plasma Focus ◽  
Dense Plasma ◽  
Carbon Film ◽  
Film Deposition ◽  
Dense Plasma Focus ◽  
Energetic Ions ◽  
Thin Carbon ◽  
Thin Carbon Film

Optical and electronic properties of nitrogen-implanted diamond-like carbon films

1994 ◽  
Vol 9 (1) ◽  
pp. 85-90 ◽  
Author(s):  
G.L. Doll ◽  
J.P. Heremans ◽  
T.A. Perry ◽  
J.V. Mantese
Keyword(s):  
Amorphous Carbon ◽  
Carbon Film ◽  
Film Surface ◽  
Carbon Films ◽  
Localized States ◽  
Diamond Like Carbon ◽  
Nitrogen Implantation ◽  
Electrical Measurements ◽  
Nitrogen Ion ◽  
Ion Implanted

Optical and electrical measurements on nitrogen ion-implanted diamond-like carbon films are presented. Raman scattering measurements, which probe the crystallinity of the film surface, indicate that nitrogen implantation reduces the finite crystallographic order in the pristine carbon films. The absence of molecular vibrations in the infrared absorption spectra of the films argues against a polymeric structure of the ion-implanted films. Spectroscopic ellipsometry experiments determine the change in the optical constants of the carbon film due to nitrogen implantation. Electrical de conductivity measurements are interpreted within the framework of a schematic density of states picture of graphitic τ-electrons in an amorphous carbon system. Taken collectively, the optical and electrical measurements suggest that nitrogen implantation increases the density of localized states within the 1.5 eV bandgap of the quasi-amorphous carbon film, thereby reducing the bandgap and increasing the conductivity of the nitrogen-implanted films.

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