Ionization Energy and Electron Affinity of Clean and Oxidized AlxGa1−xN(0001) Surfaces

2001 ◽  
Vol 680 ◽  
Author(s):  
H. Nienhaus ◽  
M. Schneider ◽  
S.P. Grabowski ◽  
W. Mönch ◽  
R. Dimitrov ◽  
...  
Keyword(s):  
Electron Affinity ◽  
Ionization Energy ◽  
Room Temperature ◽  
Aluminum Content ◽  
Composition Range ◽  
Photoemission Spectroscopy ◽  
Negative Electron Affinity ◽  
Atom Flux ◽  
General Chemical ◽  
Good Agreement

ABSTRACTIonization energies and electron affinities of clean AlxGa1−xN(0001) surfaces were investigated by ultraviolet photoemission spectroscopy over the whole composition range. The samples were cleaned with cycles of N+-ion sputtering and annealing partly within a Ga atom flux. The ionization energy is measured as 6.5 eV and is almost independent of the aluminum content in good agreement with the general chemical trend. The electron affinity decreases linearly with composition from 3.1 eV for GaN to 0.25 eV for AlN. No evidence for negative electron affinity at AlN(0001) surfaces was found. Adsorption of oxygen at room temperature leads to a significant increase of the ionization energy and electron affinity. With AlN(0001) surfaces, an oxygen uptake of 0.6 monolayers is observed after exposures of 108 Langmuirs and the ionization energy increases by approximately 2 eV.

Electron effective-mass values in GaxIn1−xSb alloys

1969 ◽  
Vol 47 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Marcel J. Aubin ◽  
Mathew B. Thomas ◽  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Effective Mass ◽  
High Frequency ◽  
Room Temperature ◽  
Composition Range ◽  
Bridgman Technique ◽  
Scattering Parameter ◽  
Electron Effective Mass ◽  
High Frequency Dielectric Constant ◽  
The Matrix ◽  
Good Agreement

Room-temperature measurements of Faraday rotation, magneto–thermoelectric power, and infrared reflectance have been made on homogeneous coarsely polycrystalline n-type samples of GaxIn1−xSb alloys produced by the horizontal Bridgman technique. Using these data and a Kane equation for the (000) conduction band, values of the bottom of the band effective mass m00* have been determined over the composition range 0 < x < 0.85, i.e. the range in which the subsidiary [Formula: see text] minima make no contribution. The results from the three different techniques show very good agreement. From the data, values are obtained also for the square of the matrix element P2, the high-frequency dielectric constant ε∞, and the scattering parameter s for the various alloy specimens.

Electron Emission from a Diamond (111) p–i–n+Junction Diode with Negative Electron Affinity during Room Temperature Operation

2010 ◽  
Vol 3 (4) ◽  
pp. 041301 ◽  
Author(s):  
Daisuke Takeuchi ◽  
Toshiharu Makino ◽  
Hiromitsu Kato ◽  
Masahiko Ogura ◽  
Norio Tokuda ◽  
...  
Keyword(s):  
Electron Affinity ◽  
Electron Emission ◽  
Room Temperature ◽  
Negative Electron Affinity ◽  
Junction Diode ◽  
Room Temperature Operation

scholarly journals Filled and empty states of Zn-TPP films deposited on Fe(001)-p(1×1)O

2016 ◽  
Vol 7 ◽  
pp. 1527-1531 ◽  
Author(s):  
Gianlorenzo Bussetti ◽  
Alberto Calloni ◽  
Rossella Yivlialin ◽  
Andrea Picone ◽  
Federico Bottegoni ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Electron Affinity ◽  
Ionization Energy ◽  
Electronic States ◽  
Single Layer ◽  
Photoemission Spectroscopy ◽  
Organic Film ◽  
Interface Dipole ◽  
Inverse Photoemission ◽  
Inverse Photoemission Spectroscopy

Zn-tetraphenylporphyrin (Zn-TPP) was deposited on a single layer of metal oxide, namely an Fe(001)-p(1×1)O surface. The filled and empty electronic states were measured by means of UV photoemission and inverse photoemission spectroscopy on a single monolayer and a 20 monolayer thick film. The ionization energy and the electron affinity of the organic film were deduced and the interface dipole was determined and compared with data available in the literature.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

An interpretation on the thermodynamic properties of liquid Pb–Te alloys

2020 ◽  
Vol 39 (1) ◽  
pp. 297-303
Author(s):  
Toru Akasofu ◽  
Masanobu Kusakabe ◽  
Shigeru Tamaki
Keyword(s):  
Thermodynamic Properties ◽  
Electron Affinity ◽  
Ionization Energy ◽  
Narrow Band ◽  
Structural Information ◽  
Lead Telluride ◽  
Liquid Lead ◽  
Metallic State ◽  
Ternary Solution ◽  
Conduction Electrons

AbstractThe bonding character of liquid lead telluride \text{PbTe} is thermodynamically investigated in detail. Its possibility as an ionic melt composed of cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} is not acceptable, by comparing the ionization energy of \text{Pb} atom, electron affinity of \text{Te} atom and the ionic bonding energy due to the cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} with the help of structural information. Solid lead telluride PbTe as a narrow band gap semiconductor might yield easily the overlapping of the tail of valence band and that of conduction one. And on melting, it becomes to an ill-conditioned metallic state, which concept is supported by the electrical behaviors of liquid Pb–Te alloys observed by the present authors. As structural information tells us about the partial remain of some sorts of covalent-type mono-dipole and poly-dipole of the molecule \text{PbTe}, all systems are thermodynamically explained in terms of a mixture of these molecules and cations {\text{Pb}}^{4+} and {\text{Te}}^{2+} and a small amount of the conduction electrons are set free from these elements based on the ternary solution model.

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