Geometric ordering, surface chemistry, band bending, and work function at decapped GaAs(100) surfaces

1992 ◽  
Vol 46 (20) ◽  
pp. 13293-13302 ◽  
Author(s):  
I. M. Vitomirov ◽  
A. Raisanen ◽  
A. C. Finnefrock ◽  
R. E. Viturro ◽  
L. J. Brillson ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Work Function ◽  
Band Bending

scholarly journals Engineering the work function of solution-processed electrodes of silver nanocrystal thin film through surface chemistry modification

APL Materials ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 121105 ◽  
Author(s):  
Mingi Seong ◽  
Haneun Kim ◽  
Seung-Wook Lee ◽  
Donghun Kim ◽  
Soong Ju Oh
Keyword(s):  
Thin Film ◽  
Surface Chemistry ◽  
Work Function ◽  
Solution Processed ◽  
Surface Chemistry Modification

Built-in Potential of a Pentacene Pin Homojunction Studied by Ultraviolet Photoemission Spectroscopy

2010 ◽  
Vol 1270 ◽  
Author(s):  
Selina Olthof ◽  
Hans Kleemann ◽  
Björn Lüssem ◽  
Karl Leo
Keyword(s):  
Small Molecules ◽  
Work Function ◽  
Photoelectron Spectroscopy ◽  
Photoemission Spectroscopy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Organic P ◽  
Band Bending ◽  
Silver Substrate ◽  
N Doping ◽  
Ultraviolet Photoemission Spectroscopy

AbstractIn this paper we investigate the energetic alignment in an organic p-i-n homojunction using ultraviolet photoelectron spectroscopy. The device is made of pentacene and we emploay the small molecules NDN1 for n-doping and NDP2 for p-doping the layers. The full p-i-n structure is deposited stepwise on a silver substrate to learn about the interface dipoles and band bending effects present in the device. From the change in work function between the p- and n-doped layers we gain knowledge of the built-in potential of this junction.

scholarly journals Surface chemistry effects on work function, ionization potential and electronic affinity of Si(100), Ge(100) surfaces and SiGe heterostructures

2020 ◽  
Vol 22 (44) ◽  
pp. 25593-25605
Author(s):  
Ivan Marri ◽  
Michele Amato ◽  
Matteo Bertocchi ◽  
Andrea Ferretti ◽  
Daniele Varsano ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Surface Chemistry ◽  
Work Function ◽  
Ionization Potential ◽  
Many Body ◽  
Many Body Perturbation Theory ◽  
The Many ◽  
Electronic Affinity

Surface chemistry effects are calculated within the many body perturbation theory for Si(100), Ge(100) and SiGe surfaces.

Very Low Pressure Oxidation of Si and Ge Surfaces

1990 ◽  
Vol 204 ◽  
Author(s):  
Iain D. Baikie
Keyword(s):  
Work Function ◽  
Substantial Reduction ◽  
Second Phase ◽  
Kelvin Probe ◽  
Band Bending ◽  
Effective Electron ◽  
Adsorption Phase ◽  
Dipole Layer ◽  
Function Change ◽  
Work Function Change

ABSTRACTAlthough the oxidation of Si(111) 7×7, Ge(111) 2×8 surfaces are relatively well understood very little work has been performed at sub monolayer coverage. We have utillsed a custom-built high resolution Kelvin probe to follow the changes in work function, and changes in band-bending and surface state occupancy via Surface Photovoltage Spectroscopy (SPV). The Kelvin probe Is an Ideal tool for such analysis due to Its extremely high surface sensitivity, equivalent to 4×1010 molecules/cm2, or 0.01% of the available sites.We observe a very rapid initial adsorption phase, which has not been found by other surface probes, e.g., AES, EELS, etc, corresponding to the formation of an elementary dipole layer. During this phase the Increase In the effective electron affinity with oxygen uptake achieves a maximum of 1V at 0.3 monolayer (ML), on SI(111) at 300 K. We report, for the first time, SPV spectra of SI(111), at 100 K, indicating quenching of a band of surface states centered around the fermi-level, quenching Is completed at the max-Imum of the work function change.The second adsorption phase, involving oxygen penetration through the surface layer and incorporation Into the lattice, commences at 0.25 ML for Si(111) at 300 K. a much earlier stage than previously reported. Further. we find evidence of a metastable SiO2 precursor at coverages below 1 ML. The dipole layer formation (and breakup) is shown to be very sensitive to both temperature and amount of surface Carbon contamination. The second phase also Involves a substantial reduction In band-bending to nearly flat bands at 2 ML, accounting for 20% of the work function change In the case of SI and almost 90% for Ge.

Role of Surfaces and Interfaces for the Electronic Properties of Conducting Oxides

2001 ◽  
Vol 666 ◽  
Author(s):  
Andreas Klein
Keyword(s):  
Work Function ◽  
Electronic Properties ◽  
Photoelectron Spectroscopy ◽  
Band Alignment ◽  
Surface Band ◽  
Band Bending ◽  
Conducting Oxides ◽  
Degenerate Semiconductors ◽  
Surfaces And Interfaces

ABSTRACTTransparent conductive oxides (TCOs) are generally considered as degenerate semiconductors doped intrinsically by oxygen vacancies and by intentionally added dopants. For some applications a high work function is required in addition to high conductivity and it is desired to tune both properties independently. To increase the work function, the distance between the Fermi energy and the vacuum level must increase, which can be realized either by electronic surface dipoles or by space charge layers. Photoelectron spectroscopy data of in-situ prepared samples clearly show that highly doped TCOs can show surface band bending of the order of 1 eV. It is further shown that the band alignment at heterointerfaces between TCOs and other materials, which are crucial for many devices, are also affected by such band bending. The origin of the band bending, which seems to be general to all TCOs, depends on TCO thin film and surface processing conditions. The implication of surface band bending on the electronic properties of thin films and interfaces are discussed.

Application of Surface Photovoltage Spectroscopy in Surface Analysis

1992 ◽  
Vol 261 ◽  
Author(s):  
Iain D. Baikie ◽  
Eimert Venderbosch ◽  
Birgitta Hall
Keyword(s):  
Work Function ◽  
Surface Analysis ◽  
Electron Affinity ◽  
Surface Photovoltage ◽  
Semiconductor Surface ◽  
Temperature Dependent ◽  
Band Bending ◽  
Surface Photovoltage Spectroscopy ◽  
Wide Range

ABSTRACTExtension of the Kelvin probe vibrating capacitor technique of measuring work function, via Illumination of the semiconductor surface, i.e., Surface Photovoltage Spectroscopy (SPS), has many potential applications in the field of surface analysis.The combination of broad-band (white) and monochromatic radiation, together with measurement of the dark signal permits complete characterisation of the semiconductor work function via determination of the electron-affinity, surface potential and Local DensIty-of-States (LDOS). The work function is an extremely sensitive indicator of a wide range of surface processes, e.g., particle adsorption, stress, defect creation, phase-transitions, etc.We Illustrate application of this technique in the study of the temperature dependent initial oxidation behaviour of p-type Si(111) 7×7 between 100 and 300 K. The SPV response of the clean surface at 100 K corresponds to the capture of photo-stimulated electrons by a band of surface states centered around 1.4, 1.7, 1.9 and 2.4 eV. This response completely disappears at the peak of the (dark) work function change (0.3L) corresponding to a near complete removal of dangling bond states. The temperature-dependent white-light SPS response permits determination of the band-bending throughout the adsorption process. We observe that at 100 K the band-bending substantially decreases during the initial adsorption phase (0.1 L), after this dose it remains constant. However at 300 K the band-bending decreases much later, i.e., >10 L, in conjunction with oxygen permeation through the surface layer.In conclusion Surface Photovoltage Spectroscopy SPS is a simple and flexible method which can be used to follow the rather complex changes occurring at the semiconductor surface. It is a non-contact, nondestructive technique which allows simultaneous determination of both semiconductor band-bending and electron affinity.

Work function, band bending, and electron affinity in surface conducting (100) diamond

2011 ◽  
Vol 208 (9) ◽  
pp. 2062-2066 ◽  
Author(s):  
M. T. Edmonds ◽  
C. I. Pakes ◽  
S. Mammadov ◽  
W. Zhang ◽  
A. Tadich ◽  
...  
Keyword(s):  
Work Function ◽  
Electron Affinity ◽  
Band Bending

Work function and band bending on clean cleaved zinc oxide surfaces

1979 ◽  
Vol 80 ◽  
pp. 261-264 ◽  
Author(s):  
H. Moormann ◽  
D. Kohl ◽  
G. Heiland
Keyword(s):  
Zinc Oxide ◽  
Work Function ◽  
Oxide Surfaces ◽  
Band Bending
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