Auger Electron Spectroscopy of The CVD Diamond Surface Under Electron Exposure

1995 ◽  
Vol 416 ◽  
Author(s):  
I. L. Krainsky ◽  
G. T. Mearini ◽  
V. M. Asnin ◽  
H. Sun ◽  
M. Foygel ◽  
...  
Keyword(s):  
Secondary Electron ◽  
Local Density ◽  
Secondary Electron Emission ◽  
Chemical Vapor ◽  
Peak Shift ◽  
Peak Position ◽  
Diamond Surface ◽  
Auger Peak ◽  
Auger Spectra ◽  
Simultaneous Study

ABSTRACTA simultaneous study of Auger spectra and secondary electron emission from the chemical vapor deposited diamond films under extended electron beam exposure is presented. Up to a 1.2 eV increase in energy of the carbon Auger peak accompanied by the decrease of the total secondary electron yield has been found. Exposure to hydrogen has resulted in recovery of the both Auger peak position and secondary yield. First-principles electronic structure calculations have been carried out to interpret the Auger peak shift. The effect is shown to be due to a change in the surface upper-valence band local density of states of the diamond crystal which is dependent on the extent of hydrogen coverage of the surface.

Design of a UHV STEM for Through-The-Lens Electron Spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 380-381
Author(s):  
A. J. Bleeker ◽  
P. Kruit
Keyword(s):  
Secondary Electron ◽  
High Vacuum ◽  
Secondary Electron Emission ◽  
Auger Spectroscopy ◽  
Scanning Transmission Electron Microscope ◽  
Point Of View ◽  
Ultra High Vacuum ◽  
Scanning Transmission ◽  
Auger Spectra ◽  
Coincidence Measurements

Combining of the high spatial resolution of a Scanning Transmission Electron Microscope and the wealth of information from the secondary electrons and Auger spectra opens up new possibilities for materials research. In a prototype instrument at the Delft University of Technology we have shown that it is possible from the optical point of view to combine STEM and Auger spectroscopy [1]. With an Electron Energy Loss Spectrometer attached to the microscope it also became possible to perform coincidence measurements between the secondary electron signal and the EELS signal. We measured Auger spectra of carbon aluminium and Argon gas showing energy resolutions better than 1eV [2]. The coincidence measurements on carbon with a time resolution of 5 ns yielded basic insight in secondary electron emission processes [3]. However, for serious Auger spectroscopy, the specimen needs to be in Ultra High Vacuum. ( 10−10 Torr ). At this moment a new setup is in its last phase of construction.

Valence states analysis of Ca and Si in CaSi2 during CaSi2–H2O reaction

1998 ◽  
Vol 13 (5) ◽  
pp. 1401-1404 ◽  
Author(s):  
S. Abe ◽  
H. Nakayama ◽  
T. Nishino ◽  
S. Iida
Keyword(s):  
Applied Voltage ◽  
Lower Energy ◽  
Valence Electron ◽  
Peak Shift ◽  
Peak Position ◽  
Pt Electrode ◽  
Electron States ◽  
Dc Voltage ◽  
Valence States ◽  
Auger Spectra

The changes in the valence electron states of CaSi2 during the chemical reaction with H2O have been investigated by Auger Valence Electron Spectroscopy (AVES). In order to study the reaction process, the reaction was precisely controlled by applying dc voltage between Pt electrode and CaSi2 specimen. The Si[2s, 2p,V] Auger spectra of CaSi2 specimen remain unchanged under the applied voltage lower than −15 V relative to the Pt electrode in H2O. At higher applied voltage, 3p components of Si[2s, 2p, V] (V = 3s, 3p) Auger spectra get weak while the 3s components increase drastically. The peak position due to Ca[2p, 3p, 3p] transitions gradually shifted toward the lower energy side by raising the applied voltage. The peak shift is due to the formation of Ca–O bonds in CaSi2. A new peak, which arises from the split of the valence electron states in Ca atoms due to the Ca–O bonds, appeared in Ca[2p, 3p,V] Auger spectra for CaSi2 after the reaction with H2O.

Secondary Electron Emission Spectroscopy of Crystalline and Non-Crystalline Carbon Allotropes

1990 ◽  
Vol 201 ◽  
Author(s):  
Alon Hoffman ◽  
Steven Prawer
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Ion Irradiation ◽  
Quartz Substrate ◽  
Natural Diamond ◽  
Pyrolytic Graphite ◽  
Secondary Electron Emission ◽  
Diamond Surface ◽  
Diamond Surfaces ◽  
Diamond Thin Film

AbstractThe Secondary Electron Emission (SEE) spectra of type Ha diamond, highly oriented pyrolytic graphite (HOPG), amorphous carbon (e-beam evaporated), glassy carbon and amorphic-diamond (filtered arc evaporated) were measured in the 0–80 eV electron kinetic energy range, and found to be very distinctive for the different carbon allotropcs. The sensitivity of SEE spectroscopy to crystal damage for the type Ha diamond surface was studied by performing SEE measurements as function of 1 keV argon ion irradiation dose. Two examples of the use of SEE in the characterization of diamond surfaces are presented. In the first, the crystalline quality of the back and front surfaces of a chemically vapour deposited diamond thin film which had dclaminated from a fused quartz substrate were compared using SEE and, in the second, SEE was used to provide a qualitative estimate of the damage induced by mechanical polishing of a natural diamond surface.

Stable secondary electron emission from chemical vapor deposited diamond films coated with alkali‐halides

1995 ◽  
Vol 66 (2) ◽  
pp. 242-244 ◽  
Author(s):  
G. T. Mearini ◽  
I. L. Krainsky ◽  
J. A. Dayton ◽  
Yaxin Wang ◽  
Christian A. Zorman ◽  
...  
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Alkali Halides ◽  
Chemical Vapor Deposited

Surface damage effects on secondary electron emission From the negative electron affinity diamond surface

1995 ◽  
Vol 416 ◽  
Author(s):  
D. P. Malta ◽  
J. B. Posthill ◽  
T. P. Humphreys ◽  
M. J. Mantini ◽  
R. J. Markunas
Keyword(s):  
Electron Affinity ◽  
Electron Emission ◽  
Photoelectron Spectroscopy ◽  
Secondary Electron ◽  
Natural Diamond ◽  
Hydrogen Plasma ◽  
Secondary Electron Emission ◽  
Surface Damage ◽  
Diamond Surface ◽  
Negative Electron Affinity

ABSTRACTThe effects of surface damage on the secondary electron emission characteristics of a natural diamond (100) surface have been investigated using ultraviolet photoelectron spectroscopy and scanning electron microscopy. Surface damage was intentionally induced by abrading the (100) diamond face with diamond paste. Removal of the damage was achieved by a sequence of ion implantation, graphitization, electrochemical etching and oxygen/argon plasma etching. Prior to characterization performed between steps in the sequence, the surface was hydrogenated by exposure to a hydrogen plasma in attempts to create a negative electron affinity surface condition. Upon removal of the surface damage, the secondary electron yield from the negative electron affinity surface was enhanced by a factor of ˜20 over that from the damaged negative electron affinity surface.

scholarly journals Probing the Optical Properties of MoS2 on SiO2/Si and Sapphire Substrates

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 740 ◽  
Author(s):  
Tao Han ◽  
Hongxia Liu ◽  
Shulong Wang ◽  
Shupeng Chen ◽  
Wei Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Vapor ◽  
Peak Shift ◽  
Peak Position ◽  
Absorption Capacity ◽  
Exciton Peak ◽  
Monolayer Mos2 ◽  
Si Substrate ◽  
Sapphire Substrates ◽  
Pl Spectrum

As an important supplementary material to graphene in the optoelectronics field, molybdenum disulfide (MoS2) has attracted attention from researchers due to its good light absorption capacity and adjustable bandgap. In this paper, MoS2 layers are respectively grown on SiO2/Si and sapphire substrates by atmospheric pressure chemical vapor deposition (APCVD). Atomic force microscopy, optical microscopy, and Raman and photoluminescence spectroscopy are used to probe the optical properties of MoS2 on SiO2/Si and sapphire substrates systematically. The peak shift between the characteristic A1g and E12g peaks increases, and the I peak of the PL spectrum on the SiO2/Si substrate redshifts slightly when the layer numbers were increased, which can help in obtaining the layer number and peak position of MoS2. Moreover, the difference from monolayer MoS2 on the SiO2/Si substrate is that the B peak of the PL spectrum has a blueshift of 56 meV and the characteristic E12g peak of the Raman spectrum has no blueshift. The 1- and 2-layer MoS2 on a sapphire substrate had a higher PL peak intensity than that of the SiO2/Si substrate. When the laser wavelength is transformed from 532 to 633 nm, the position of I exciton peak has a blueshift of 16 meV, and the PL intensity of monolayer MoS2 on the SiO2/Si substrate increases. The optical properties of MoS2 can be obtained, which is helpful for the fabrication of optoelectronic devices.

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