Decay of secondary electron emission and charging of hydrogenated and hydrogen-free diamond film surfaces induced by low energy electrons

2002 ◽  
Vol 91 (7) ◽  
pp. 4726-4732 ◽  
Author(s):  
A. Hoffman ◽  
A. Laikhtman ◽  
S. Ustaze ◽  
M. Hadj Hamou ◽  
M. N. Hedhili ◽  
...  
Keyword(s):  
Electron Emission ◽  
Diamond Film ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Low Energy ◽  
Low Energy Electrons

Secondary Electron Emission Studies of Diamond and GaN Materials

1999 ◽  
Vol 558 ◽  
Author(s):  
J.E. Yater ◽  
A. Shih ◽  
D.S. Katzer
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Cvd Diamond ◽  
Secondary Emission ◽  
Low Energy ◽  
Energy Distributions ◽  
Three Samples ◽  
Low Energy Electrons ◽  
The Impact

ABSTRACTSecondary electron emission spectroscopy is used to examine the transport and emission of low-energy electrons in several wide bandgap materials. In particular, the secondary emission properties of C(100), C(111), and CVD diamond samples are compared in order to examine the effect of crystallographic orientation on the emission characteristics. Very high yields are obtained from hydrogenated and cesiated negative-electron-affinity surfaces of all three samples, indicating that low-energy electrons are transported and emitted very efficiently in the diamond materials. While the energy distribution of the emitted electrons is found to be sharply peaked at low energy for all three samples, the energy distributions measured from the C(111) surfaces are broader and reveal structure in the energy gap. The different emission processes at the C(100) and C(111) surfaces may account for the energy distributions observed from the polycrystalline CVD diamond. Finally, initial secondary emission measurements are taken from GaN and AlGaN films grown by molecular beam epitaxy. The secondary emission is not as strong as from the diamond samples, and the measurements reveal the impact of interface and surface barriers on the emission process.

POSSIBLE "HOT" MOLECULE DESORPTION BY ELECTRON STIMULATED DECOMPOSITION OF DIHALOETHANES ON Cu(111)

1994 ◽  
Vol 01 (04) ◽  
pp. 535-538 ◽  
Author(s):  
S. TURTON ◽  
M. KADODWALA ◽  
ROBERT G. JONES
Keyword(s):  
Electron Capture ◽  
Photoelectron Spectroscopy ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Negative Ions ◽  
Low Energy ◽  
First Order ◽  
Sufficient Energy ◽  
Low Energy Electrons ◽  
Low Energy Electron

The desorption of ethene from physisorbed 1, 2-dichloroethane (DCE) and 1-bromo-2-chloroethane (BCE) on Cu(111) has been observed on irradiating the surface with electrons. The techniques used were low energy electron diffraction (LEED), Auger electron spectroscopy (AES), ultraviolet photoelectron spectroscopy (UPS), and mass spectrometric detection of the desorbed species. At 110 K physisorbed DCE and BCE underwent electron capture from low energy (<1 eV ) electrons in the secondary electron yield of the surface followed by decomposition and desorption of ethene alone. The decomposition was found to be first order in the surface coverage of the physisorbed DCE/BCE. No other molecular species desorbed from the surface, a stoichiometric amount of chemisorbed halogen was deposited and no carbon was detectable at the end of the desorption. The formation of the negative ions of these molecules by electron capture of low energy electrons in the secondary electron emission from the surface and the possible dynamics by which the negative ions undergo decomposition leaving the ethene product with sufficient energy to desorb, are discussed.

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