High-Resolution Spectroscopy of Point Defects in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
H.G. Grimmeiss ◽  
M. Kleverman ◽  
J. Olajos
Keyword(s):  
High Resolution ◽  
Transition Metals ◽  
Electronic Properties ◽  
Point Defects ◽  
High Resolution Spectroscopy ◽  
Paper Briefly ◽  
Excitation Spectra ◽  
Photothermal Ionization ◽  
Recent Developments ◽  
Photothermal Ionization Spectroscopy

AbstractThe paper briefly outlines recent developments in high resolution spectroscopy of point defects in silicon. One of the methods, namely photothermal ionization spectroscopy (PTIS) is discussed in detail. Impurities induced by selenium and several transition metals are used as examples m order to illustrate the powerful scope of both transmission and PTIS measurements. These measurements are capable of providing unique information on the electronic properties of point defects, even when the defects exhibit complex excitation spectra.

Developments in experimental neutron physics at the Institut Laue—Langevin

1980 ◽  
Vol 290 (1043) ◽  
pp. 673-681 ◽  
Keyword(s):  
High Resolution ◽  
Energy Resolution ◽  
Spin Echo ◽  
Bragg Diffraction ◽  
High Resolution Spectroscopy ◽  
Neutron Spectroscopy ◽  
Neutron Physics ◽  
Cold Neutrons ◽  
Recent Developments

A report and survey are given dealing with a variety of recent developments in neutron spectroscopy, diffraction and beam techniques, referring to work at the Institut Laue-Langevin. Subjects such as high resolution spectroscopy by 90° Bragg diffraction and spin echo analysis (leading to 10 -7 to 10 -8 eV energy resolution), spin polarizers, focusing crystals, modern multicounters, and methods dealing with neutrons of energies in the 10 -7 eV region (ultra-cold neutrons), are dealt with.

scholarly journals Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

Sensors ◽  
2009 ◽  
Vol 9 (11) ◽  
pp. 9039-9057 ◽  
Author(s):  
Francis Hindle ◽  
Chun Yang ◽  
Gael Mouret ◽  
Arnaud Cuisset ◽  
Robin Bocquet ◽  
...  
Keyword(s):  
High Resolution ◽  
High Resolution Spectroscopy ◽  
Recent Developments

scholarly journals Sub-Doppler High-Resolution Spectroscopy of 15V Band of CS2 and the Zeeman Effect

1995 ◽  
Vol 15 (2-4) ◽  
pp. 131-143 ◽  
Author(s):  
Atsushi Doi ◽  
Masaya Ohtsuka ◽  
Kiyoshi Nishizawa ◽  
Masaaki Baba ◽  
Hajime Katô
Keyword(s):  
High Resolution ◽  
Zeeman Effect ◽  
Orbit Interaction ◽  
High Resolution Spectroscopy ◽  
Spin Orbit ◽  
Excitation Spectra ◽  
Main Band ◽  
Spin Orbit Interaction ◽  
Vibrational Levels ◽  
Almost All

Excitation spectra and the Zeeman spectra of CS2 in the region of 31320-31445 cm-1were measured with sub-Doppler resolution. Observed rotational lines were classified to 14 series of lines (vibronic bands) and were named by the wavenumbers of their band origins. The 31344.9 band is the strongest one and is assigned as the main band of the V1B20v20(K=0) – X1∑g+ 0000 transition. Most of the extra bands may be allowed by the vibronic interaction between the V1B20v20(K=0) level and singlet levels, which are mostly high vibrational levels of the 1A1(X1∑g+) state. The Zeeman splittings are observed for several lines in almost all bands. These may be originating from the spin-orbit interaction between the rotational levels, which have accidentally nearly the same energy, of the 1A1(X1∑g+) state and the 3A2 (3Δu ) or/and 3B2 (3Δu) state.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

High-resolution microscopy of twin boundaries in gold

1987 ◽  
Vol 45 ◽  
pp. 260-261
Author(s):  
William Krakow ◽  
David A. Smith
Keyword(s):  
High Resolution ◽  
Specimen Preparation ◽  
Gold Films ◽  
Boundary Area ◽  
Transmission Electron ◽  
Recent Developments ◽  
Tilt Boundaries ◽  
High Resolution Microscopy ◽  
Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

Intercalation of First Row Transition Metals inside Covalent-Organic Frameworks (COF): a Strategy to Fine Tune the Electronic Properties of Porous Crystalline Materials

2018 ◽  
Author(s):  
Srimanta Pakhira ◽  
Jose Mendoza-Cortes
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Electronic Properties ◽  
High Surface ◽  
Electronic Devices ◽  
High Surface Area ◽  
Main Role ◽  
Covalent Organic Frameworks ◽  
Porous Network ◽  
Crystalline Materials

<div>Covalent organic frameworks (COFs) have emerged as an important class of nano-porous crystalline materials with many potential applications. They are intriguing platforms for the design of porous skeletons with special functionality at the molecular level. However, despite their extraordinary properties, it is difficult to control their electronic properties, thus hindering the potential implementation in electronic devices. A new form of nanoporous material, COFs intercalated with first row transition metal is proposed to address this fundamental drawback - the lack of electronic tunability. Using first-principles calculations, we have designed 31 new COF materials <i>in-silico</i> by intercalating all of the first row transition metals (TMs) with boroxine-linked and triazine-linked COFs: COF-TM-x (where TM=Sc-Zn and x=3-5). This is a significant addition considering that only 187 experimentally COFs structures has been reported and characterized so far. We have investigated their structure and electronic properties. Specifically, we predict that COF's band gap and density of states (DOSs) can be controlled by intercalating first row transition metal atoms (TM: Sc - Zn) and fine tuned by the concentration of TMs. We also found that the $d$-subshell electron density of the TMs plays the main role in determining the electronic properties of the COFs. Thus intercalated-COFs provide a new strategy to control the electronic properties of materials within a porous network. This work opens up new avenues for the design of TM-intercalated materials with promising future applications in nanoporous electronic devices, where a high surface area coupled with fine-tuned electronic properties are desired.</div>

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