Model for the Surface Potential Barrier and the Periodic Deviations in the Schottky Effect

1958 ◽  
Vol 111 (2) ◽  
pp. 394-402 ◽  
Author(s):  
P. H. Cutler ◽  
J. J. Gibbons
Keyword(s):  
Potential Barrier ◽  
Surface Potential ◽  
Schottky Effect

Evolution of surface potential barrier for negative-electron-affinity GaAs photocathodes

2009 ◽  
Vol 105 (1) ◽  
pp. 013714 ◽  
Author(s):  
Jijun Zou ◽  
Benkang Chang ◽  
Zhi Yang ◽  
Yijun Zhang ◽  
Jianliang Qiao
Keyword(s):  
Potential Barrier ◽  
Surface Potential ◽  
Electron Affinity ◽  
Negative Electron Affinity

Contactless electroreflectance studies of surface potential barrier for N- and Ga-face epilayers grown by molecular beam epitaxy

2013 ◽  
Vol 103 (5) ◽  
pp. 052107 ◽  
Author(s):  
R. Kudrawiec ◽  
L. Janicki ◽  
M. Gladysiewicz ◽  
J. Misiewicz ◽  
G. Cywinski ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Potential Barrier ◽  
Surface Potential ◽  
Molecular Beam

scholarly journals Charge Densities above Pulsar Polar Caps

2000 ◽  
Vol 177 ◽  
pp. 463-464
Author(s):  
A. Jessner ◽  
H. Lesch ◽  
Th. Kunzl
Keyword(s):  
Neutron Star ◽  
Electric Field ◽  
Work Function ◽  
Potential Barrier ◽  
Electric Fields ◽  
Surface Potential ◽  
Thermal Emission ◽  
Equilibrium Density ◽  
Charge Densities ◽  
Polar Caps

A simplified model provided the framework for our investigation into the distribution of energy and charge densities above the polar caps of a rotating neutron star. We assumed a neutron star withm= 1.4M⊙,r= 10km, dipolar field |B0| = 1012G,B||Ω and Ω = 2Π · (0.5s)−1. The effects of general relativity were disregarded. The induced accelerating electric fieldE||reachesE0= 2.5 · 1013V m−1at the surface near the magnetic poles. The current density along the field lines has an upper limitnGJ, when the electric field of the charged particle flow cancels the induced electric field: At the polesnGJ(r=rns,θ= 0) = 1.4 · 1017m−3.The work function(surface potential barrier)EWis approximated by the Fermi energyEFof magnetised matter. Following Abrahams and Shapiro (1992) one needs to revise the surface density from the canonical 1.4 · 108kg m−3down toρFe = 2.9 · 107kg m−3. Withwe obtain a value ofEF=Ew= 417eV. There are two relevant particle emission processes:Field (cold cathode) emissionby quantum-mechanical tunneling of charges through the surface potentialandthermal emissionwhich is a purely classical process. In strong electric fields it is enhanced by the lowering of the potential barrier due to the Schottky effect. The combined Dushman-Schottky equationwithtells us, thatat temperatures> 2 · 105K the the Goldreich-Julian current can be supplied thermal emission alone. The surface temperature however has a lower limit in the order of 105K due to the rotational braking. Therefore, in most cases a sufficient supply of charges for the Goldreich-Julian current is available and the electrical field accelerating the particles will be quenched as a result of their abundance. Otherwise a residual equilibrium electric field Eeqremains with:and hence the equilibrium density is:n=nfieid(Eeq,EW) +nDS(Eeq,EW,T) For a temperature just below the onset of thermal emission (T= 1.85 · 105K) the charge density is found to vary almost linearly with the work functionEWfor values ofEWbetween 0.3 and 2 keV. At the chosen value forEWof 417 eVthe residual electric field amounts to only 8.5% of the vacuum value. Even in the residual electric field the particles are rapidly accelerated to relativistic energies balanced by inverse Compton and curvature radiation losses.

Surface Charge Imaging in Semiconductor Wafers by Surface Photovoltage (SPV)

1992 ◽  
Vol 261 ◽  
Author(s):  
Piotr Edelman ◽  
Jacek Lagowski ◽  
Lubek Jastrzebski
Keyword(s):  
Surface Charge ◽  
Potential Barrier ◽  
Surface Potential ◽  
Surface Photovoltage ◽  
High Excitation ◽  
Wafer Scale ◽  
Contact Measurement

ABSTRACTWe present fast, wafer-scale imaging of the surface charge achieved via non-contact measurement of the surface potential barrier by surface photovoltage (SPV) under high excitation levels. The approach is capable of resolving surface charge differences as small as 108 q/cm2. Fundamentals of surface charge imaging are discussed, and the method is compared with standard SPV contamination mapping. Examples include problems relevant to silicon IC fabrication and surface charge maps of GaAs and InP.

scholarly journals Effect of surface potential barrier on electron escape probability of GaN photocathode

2012 ◽  
Vol 61 (6) ◽  
pp. 068501
Author(s):  
Yang Yong-Fu ◽  
Fu Rong-Guo ◽  
Zhang Yi-Jun ◽  
Wang Xiao-Hui ◽  
Zou Ji-Jun
Keyword(s):  
Potential Barrier ◽  
Surface Potential ◽  
Escape Probability ◽  
Electron Escape ◽  
Effect Of Surface

scholarly journals Phase Transition Effect on Ferroelectric Domain Surface Charge Dynamics in BaTiO3 Single Crystal

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4463
Author(s):  
Dongyu He ◽  
Xiujian Tang ◽  
Yuxin Liu ◽  
Jian Liu ◽  
Wenbo Du ◽  
...  
Keyword(s):  
Phase Transition ◽  
Domain Wall ◽  
Single Crystal ◽  
Surface Charge ◽  
Potential Barrier ◽  
Surface Potential ◽  
Topological Defects ◽  
Ferroelectric Domain ◽  
Charge Dynamics ◽  
Surrounding Environment

The ferroelectric domain surface charge dynamics after a cubic-to-tetragonal phase transition on the BaTiO3 single crystal (001) surface was directly measured through scanning probe microscopy. The captured surface potential distribution shows significant changes: the domain structures formed rapidly, but the surface potential on polarized c domain was unstable and reversed its sign after lengthy lapse; the high broad potential barrier burst at the corrugated a-c domain wall and continued to dissipate thereafter. The generation of polarization charges and the migration of surface screening charges in the surrounding environment take the main responsibility in the experiment. Furthermore, the a-c domain wall suffers large topological defects and polarity variation, resulting in domain wall broadening and stress changes. Thus, the a-c domain wall has excess energy and polarization change is inclined to assemble on it. The potential barrier decay with time after exposing to the surrounding environment also gave proof of the surface screening charge migration at surface. Thus, both domain and domain wall characteristics should be taken into account in ferroelectric application.

Interaction of Reactive Species Obtained by G-D Silane Decomposition with Si(111) and a-Si:H Surfaces

1987 ◽  
Vol 95 ◽  
Author(s):  
S. A. Cruz ◽  
V. M. Mendez-Rosales
Keyword(s):  
Potential Barrier ◽  
Surface Potential ◽  
Reactive Species ◽  
Interatomic Potentials ◽  
Average Surface ◽  
Thomas Fermi ◽  
First Case ◽  
Crystalline Surface ◽  
Total Interaction

AbstractWe calculate the average surface potential barrier for incorporation of H, Si, SiHb (n=1–4) into films of a-Si:H as well as crystalline Si(111) surfaces. In the first case a local amorphous configuration for the surface is employed through a representative cluster(Si29 H1 0 ) forming 5, 6, 7 Si atom rings. For the crystalline surface, several layers of Si atoms are considered. Pairwise superposition of combined Morse and Thomas-Fermi-Moliére interatomic potentials is assumed for the total interaction between the incoming species and the surface.

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