scholarly journals Absolute Photoionization Cross Sections of the Acceptor State Level of Chromium in Indium Phosphide

1985 ◽  
Vol 46 ◽  
Author(s):  
Georges Bremond ◽  
G. Guillot ◽  
A. Nouailhat ◽  
G. Picoli
Keyword(s):  
Indium Phosphide ◽  
Conduction Band ◽  
Cross Section ◽  
Cross Sections ◽  
Selection Rule ◽  
Deep Level ◽  
State Level ◽  
Acceptor State ◽  
Internal Transition ◽  
Resonant Character

AbstractWe have analyzed the photoionization of Cr2+ in InP by the Deep Level Optical Spectroscopy (D.L.O.S.). The σ°n cross section exhibits both a resonant and non resonant character. The former corresponds to the internal transition 5T2-5E of Cr2+ while the threshold of the second allows us to locate the Cr2+/Cr3+ level below the conduction band. The absolute photoionization cross sections towards the two bands are very similar. In particular no selection rule seems to work.

scholarly journals Absolute photoionization cross sections of the acceptor state level of chromium in indium phosphide

1986 ◽  
Vol 59 (6) ◽  
pp. 2038-2043 ◽  
Author(s):  
G. Bremond ◽  
G. Guillot ◽  
A. Nouailhat ◽  
G. Picoli
Keyword(s):  
Indium Phosphide ◽  
Cross Sections ◽  
State Level ◽  
Acceptor State

Meyer-Neldel Rule in Deep-Level-Transient-Spectroscopy and its Ramifications

2003 ◽  
Vol 763 ◽  
Author(s):  
Richard S. Crandall
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Capture Cross ◽  
Emission Data ◽  
The Cross ◽  
Transient Spectroscopy ◽  
Capture Cross Sections

AbstractThis paper presents data showing a Meyer-Neldel rule (MNR) in InGaAsN alloys. It is shown that without this knowledge, significant errors will be made using Deep-Level Transient-Spectroscopy (DLTS) emission data to determine capture cross sections. By correctly accounting for the MNR in analyzing the DLTS data the correct value of the cross section is obtained.

Analysis of Emission Rate Measurements in a Material Showing a Meyer-Neldel- Rule

2003 ◽  
Vol 799 ◽  
Author(s):  
Richard S. Crandall
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Emission Rate ◽  
Deep Level ◽  
Entropy Change ◽  
Emission Data ◽  
Entropy Changes ◽  
Deep Traps ◽  
Transient Spectroscopy ◽  
Transition Entropy

ABSTRACTThis paper presents data showing a Meyer-Neldel rule (MNR) in InGaAsN alloys. It is shown that without this knowledge, significant errors can be made using Deep-Level Transient-Spectroscopy (DLTS) emission data to determine capture cross sections. The errors arise because of the neglect of significant transition entropy changes associated with multiphonon excitation of charge from deep traps. Ignoring the entropy change results in cross section values ranging over five orders-of-magnitude in InGaAsN alloys and 18 orders-of-magnitude in CuInGaSe alloys. Only by correctly accounting for the MNR and the accompanying entropy changes in analyzing the DLTS data will the correct value of the cross section be obtained.

A Simulation of Electron Scattering in Metals and its Application for Scanning Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 420-421
Author(s):  
Masatoshi Kotera ◽  
Ryoji Ijichi ◽  
Takafumi Fujiwara ◽  
Hiroshi Suga ◽  
David B. Wittry
Keyword(s):  
Elastic Scattering ◽  
Conduction Band ◽  
Cross Section ◽  
Conduction Electron ◽  
Electron Scattering ◽  
Cross Sections ◽  
Electron Ionization ◽  
Plasmon Excitation ◽  
Electron Trajectories ◽  
Scanning Electron

In a recent research, the scanning electron microscope(SEM) has been shown to provide spatial resolution of less than 0.5nm. With the knowledge of the ultimate resolution or the factor which controls the resolution, it is possible to optimize the specimen preparation method and the choice of various electron beam parameters (eg. acceleration voltage etc.) For a precise discussion of the SEM image, it is necessary to take into account not only the signal (electron) production and the propagation in a specimen and its emission from the surface, but also electron trajectories in vacuum toward the detector. However, electron scattering process in the specimen does not depend on the detection system, and the resolution is mainly attributed to the spatial distribution of the electron emission from the specimen surface. Here, we focused on the electron scattering mechanisms in metals and developed a Monte Carlo simulation model of electron trajectories. Also, this simulation is applied to evaluate a compositional contrast in the SEM.In the present study electron interactions with atomic potential, inner-shell electrons, conduction electrons are taken into account. Cross sections calculated by the present model are shown in Fig.1 for [l]elastic scattering, [2]inner-shell (1s, 2s, 2p for Al) electron ionization, [3]conduction electron ionization through non-radiative plasmon decay, and [4] stable plasmon excitation in the conduction band electrons for Al. For the elastic scattering, the Mott cross section is used. For inner-shell electron ionizations by an electron collision, the Gryzinski equation is used. In order to express the plasmon-electron interaction in a free electron gas at the conduction band, the Lindhard treatment is used. This treatment is based on the random phase approximation in the dielectric response function of metals. The cross section is shown in a unit of the inverse mean free path. The cross sections for conduction electron ionization and the plasmon excitation agree with the data of Tung, Ashley, and Ritchie. Cross sections for inner-shell electron ionization, which Tung et al. have derived using the generalized oscillator strength, are also shown in Fig.1 for a comparison.

Heterogeneous Causality Between Telecommunications and Economic Growth: An Application of Hurlin–Venet Process to the Indian States

2021 ◽  
pp. 097493062110589
Author(s):  
Rochna Arora ◽  
Baljit Kaur
Keyword(s):  
Economic Growth ◽  
Cross Section ◽  
Cross Sections ◽  
State Level ◽  
Jel Classification ◽  
Causal Mechanism ◽  
Indian States ◽  
Independent Variables ◽  
State Economy ◽  
Bidirectional Relationship

Keeping in mind the importance of telecommunications sector for India especially post the reform of 1991, the study seeks to study the causal relationship between telecommunication and economic growth for selected panel of 17 Indian states by implicitly taking into account panel heterogeneity. Using Hurlin–Venet causal mechanism, the study investigates homogeneous causality (HC) as against heterogeneous causality (HEC). Homogeneous non-causality and HC hypothesis both of which assume homogeneity are rejected in both the directions thereby implying that Indian panel is made up of heterogeneous cross sections. After this HEC tests are conducted namely heterogeneous non-causality (HENC) and HEC for each and every cross section. The results from HENC and HEC test show that six states show up unidirectional causality from economic growth to telecommunication, four states show unidirectional causality from telecommunications to economic growth, four states show up bidirectional relationship and three states show up no causality. The results are robust to different lags for both our dependent as well as independent variables. This implies that state level differences are very much relevant for India and thus policies suitable for each state would be guided majorly by direction of relationship that is true in a particular state economy. JEL Classification: C23, L96, O40

Deep Level Defect Characterization of MBE Grown Ingaas/Gaas Heterostructures.

1990 ◽  
Vol 209 ◽  
Author(s):  
W.R. Buchwald ◽  
J.H. Zhao ◽  
F.C. Rong
Keyword(s):  
Conduction Band ◽  
Cross Sections ◽  
Deep Level ◽  
Schottky Diodes ◽  
Energy Levels ◽  
Depth Profiling ◽  
Defect Characterization ◽  
Deep Level Defect ◽  
Transient Spectroscopy

ABSTRACTDeep level transient spectroscopy (DLTS) measurements have been performed on Schottky diodes fabricated on MBE grown InGaAs/GaAs heterostructures. The dominant electron trap in this material is found at a depth of 0.30eV below the GaAs conduction band and is believed to be the previously observed M3 defect. Two other defects, at depths of 0.50eV and 0.58eV below the GaAs conduction band, were also observed. Defect depth profiling shows the 0.50eV defect to be spatially locatednear the heterointerface. The 0.58eV defect is not observed near the heterointerface but is observed in large concentrations deep in the GaAs epilayer. Optical DLTS measurements reveal deep defects at 0.54eV and 0.31eV above the InGaAs valence band as well as a large, broad peak, most likely consisting of several energy levels with varying capture cross sections,located at the heterointerface. Two carrier accumulation peaks were also seen in the CV carrier profiling measurements and are suggested to be due to two heterointerface defects located at 0.68eV and 0.87eV below the GaAs conduction band.Thermally stimulated capacitance measurements also indicate minority hole emission in this n-InGaAs/N-GaAs heterostructure.

scholarly journals Investigation of defects in structures based on BP/Si heterojunction

2021 ◽  
Vol 2103 (1) ◽  
pp. 012088
Author(s):  
A A Maksimova ◽  
A I Baranov ◽  
A V Uvarov ◽  
D A Kudryashov ◽  
A S Gudovskikh
Keyword(s):  
Activation Energy ◽  
Conduction Band ◽  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Deep Level ◽  
Admittance Spectroscopy ◽  
Capture Cross ◽  
Defect Level ◽  
Transient Spectroscopy

Abstract In this work the properties of the BP/Si heterojunction interface were investigated by capacitance methods, the deep levels transient spectroscopy method and admittance spectroscopy. Admittance spectroscopy did not detect any defects, but the deep level transient spectroscopy showed response with activation energy of 0.33 eV and capture cross-section σn=(1-10)·10-19 cm2 and defect concentration (NT) is in the order of 1013 cm-3. This defect level is a trap for electron with position of 0.33 eV below the conduction band in region near the BP/Si interface.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

Sign in / Sign up

Export Citation Format

Share Document