New Electronic Properties of Metal / III-V Compound Semiconductor Interfaces

1989 ◽  
Vol 148 ◽  
Author(s):  
L. J. Brillson ◽  
R. E. Viturro ◽  
S. Chang ◽  
J. L. Shaw ◽  
C. Mailhiot ◽  
...  
Keyword(s):  
Compound Semiconductor ◽  
Photoemission Spectroscopy ◽  
Dominant Effect ◽  
Band Bending ◽  
X Ray ◽  
Barrier Heights ◽  
Semiconductor Interfaces ◽  
Cathodoluminescence Spectroscopy ◽  
Wide Range ◽  
Spectroscopy Studies

ABSTRACTRecent studies of interface states and band bending at metal / III-V compound semiconductor interfaces reveal that these junctions are much more controllable and predictable than commonly believed. Soft x-ray photoemission spectroscopy studies demonstrate a wide range of band bending for metals on many III-V compounds, including GaAs. Cathodoluminescence spectroscopy measurements show that discrete states form at the microscopic junction which can have a dominant effect on the band bending properties. Internal photoemission measurements confirm the bulk barrier heights inferred by photoemission methods. After separating out surface chemical and bulk crystal quality effects, one finds simple, predictive barrier height variations which follow classical Schottky behavior.

Process-Dependent Electronic Structure at Metallized GaAs Contacts

1992 ◽  
Vol 260 ◽  
Author(s):  
L. J. Brillson ◽  
I. M. Vitomirov ◽  
A. Raisanen ◽  
S. Chang ◽  
R. E. Viturro ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Chemical Interaction ◽  
Deep Level ◽  
Multiple Roles ◽  
Atomic Scale ◽  
Photoemission Spectroscopy ◽  
Band Bending ◽  
Barrier Heights ◽  
Barrier Formation ◽  
Thermally Driven

ABSTRACTThe influence of metallization and processing on Schottky barrier formation provides the basis for one of several fruitful approaches for controlling junction electronic properties. Interface cathodo-and photoluminescence measurements reveal that electrically-active deep levels form on GaAs(100) surfaces and metal interfaces which depend on thermally-driven surface stoichiometry and reconstruction, chemical interaction, as well as surface misorientation and bulk crystal quality. These interface states are discrete and occur at multiple gap energies which can account for observed band bending. Characteristic trends in such deep level emission with interface processing provide guides for optimizing interface electronic behavior. Correspondingly, photoemission and internal photoemission spectroscopy measurements indicate self-consistent changes in barrier heights which may be heterogeneous and attributable to interface chemical reactions observed on a monolayer scale. These results highlight the multiple roles of atomic-scale structure in forming macroscopic electronic properties of compound semiconductor-metal junctions.

scholarly journals Methods development for diffraction and spectroscopy studies of metalloenzymes at X-ray free-electron lasers

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130590 ◽  
Author(s):  
Jan Kern ◽  
Johan Hattne ◽  
Rosalie Tran ◽  
Roberto Alonso-Mori ◽  
Hartawan Laksmono ◽  
...  
Keyword(s):  
Free Electron ◽  
Water Oxidation ◽  
Spectroscopic Studies ◽  
Free Electron Lasers ◽  
Software Suite ◽  
X Ray ◽  
Methods Development ◽  
Wide Range ◽  
Linac Coherent Light Source ◽  
Spectroscopy Studies

X-ray free-electron lasers (XFELs) open up new possibilities for X-ray crystallographic and spectroscopic studies of radiation-sensitive biological samples under close to physiological conditions. To facilitate these new X-ray sources, tailored experimental methods and data-processing protocols have to be developed. The highly radiation-sensitive photosystem II (PSII) protein complex is a prime target for XFEL experiments aiming to study the mechanism of light-induced water oxidation taking place at a Mn cluster in this complex. We developed a set of tools for the study of PSII at XFELs, including a new liquid jet based on electrofocusing, an energy dispersive von Hamos X-ray emission spectrometer for the hard X-ray range and a high-throughput soft X-ray spectrometer based on a reflection zone plate. While our immediate focus is on PSII, the methods we describe here are applicable to a wide range of metalloenzymes. These experimental developments were complemented by a new software suite, cctbx.xfel . This software suite allows for near-real-time monitoring of the experimental parameters and detector signals and the detailed analysis of the diffraction and spectroscopy data collected by us at the Linac Coherent Light Source, taking into account the specific characteristics of data measured at an XFEL.

Construction of the JAERI soft X-ray beamline for actinide material sciences

1998 ◽  
Vol 5 (3) ◽  
pp. 536-538 ◽  
Author(s):  
Takeshi Nakatani ◽  
Yuji Saitoh ◽  
Yuden Teraoka ◽  
Tetsuo Okane ◽  
Akinari Yokoya
Keyword(s):  
Photochemical Reactions ◽  
Resolving Power ◽  
Photoemission Spectroscopy ◽  
X Rays ◽  
Radioactive Materials ◽  
X Ray ◽  
Line Spacing ◽  
Material Sciences ◽  
Spectroscopy Studies ◽  
Under Construction

An undulator beamline for spectroscopy studies focusing on the electronic structure of actinide materials is under construction. Linearly or circularly polarized soft X-rays are provided by employing a variably polarizing undulator. Varied-line-spacing plane gratings and a sagittal-focusing system are used to monochromatize the undulator beam, whose energy ranges from 0.3 to 1.5 keV. A resolving power of 104 is expected in the whole energy region. These components are methodically operated by the SPring-8 beamline control system. There are three experimental stations in the beamline. In one of the stations the photoemission spectroscopy experiments are carried out at a radioisotope-controlled area where actinide compounds as well as unsealed radioactive materials are usable. Other experimental stations are planned in the beamline for surface photochemical reactions and biological applications.

Cathodoluminescence spectroscopy studies of laser‐annealed metal–semiconductor interfaces

1985 ◽  
Vol 3 (3) ◽  
pp. 1011-1015 ◽  
Author(s):  
L. J. Brillson ◽  
H. W. Richter ◽  
M. L. Slade ◽  
B. A. Weinstein ◽  
Y. Shapira
Keyword(s):  
Semiconductor Interfaces ◽  
Cathodoluminescence Spectroscopy ◽  
Spectroscopy Studies

Photoemission Studies of the Ag/InP(110) Interface: Interfacial Reactions and Schottky Barrier Formation

1983 ◽  
Vol 25 ◽  
Author(s):  
W. G. Petro ◽  
T. Kendelewicz ◽  
I. A. Babalola ◽  
I. Lindau ◽  
W. E. Spicer
Keyword(s):  
Valence Band Maximum ◽  
Interfacial Reactions ◽  
Core Level ◽  
Photoemission Spectroscopy ◽  
Band Bending ◽  
X Ray ◽  
Barrier Formation ◽  
Deconvolution Technique ◽  
P Type ◽  
Measurable Change

ABSTRACTRoom-temperature interfacial reactions at the Ag/InP (110) interface have been studied using soft x-ray photoemission spectroscopy of the In 4d and P 2p core levels. For low Ag coverages (less than 1 monolayer (ML)) no measurable change in core level shapes is observed, and the shift in core level position is due solely to band bending. At high Ag coverages (up to 72 ML) we observe dissociated In metal, P atoms near the surface, and Ag clustering. Fermi level movement is deduced from these spectra using a deconvolution technique, and pinning positions of 0.40 ± 0.05 eV below the conduction-band minimum for n-type and 0.5 ± 0.l eV above the valence-band maximum for p-type are found. These positions are in close agreement with calculations of native defect levels.

X-ray photoemission spectroscopy studies of III–V compounds prepared by atomic layer epitaxy

Vacuum ◽  
1990 ◽  
Vol 41 (4-6) ◽  
pp. 1060
Author(s):  
K. Kodama ◽  
M. Ozeki ◽  
K. Mochizuki ◽  
Y. Sakuma ◽  
N. Ohtsuka
Keyword(s):  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Photoemission Spectroscopy ◽  
X Ray ◽  
Spectroscopy Studies

scholarly journals The Fermi Level as an Energy Reference in Liquid Jet X-ray Photoelectron Spectroscopy Studies of Aqueous Solutions  

2021 ◽  
Author(s):  
Lucia Pérez Ramírez ◽  
Anthony Boucly ◽  
Florent Saudrais ◽  
F. Bournel ◽  
Jean-Jacques Gallet ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Photoemission Spectroscopy ◽  
Liquid Jet ◽  
X Ray ◽  
Invaluable Tool ◽  
Structure Of Aqueous Solutions ◽  
Spectroscopy Studies ◽  
Photocatalytic Processes

To advance an understanding of key electrochemical and photocatalytic processes that depend on the electronic structure of aqueous solutions, X-ray photoemission spectroscopy has become an invaluable tool, especially when practiced...

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