scholarly journals A study of the effect of polarization on electron, hole and exciton energy spectra of Si/SiO2 and β-HgS/CdS spherical semiconductor nanoheterosystems

2006 ◽  
Vol 10 (3) ◽  
pp. 220-226
Author(s):  
V. I. Boichuk ◽  
R. Yu. Kubay ◽  
H. M. Hodovanets ◽  
I. S. Shevchuk
Keyword(s):  
Energy Spectra ◽  
Exciton Energy ◽  
Electron Hole

scholarly journals Ultrafast non-excitonic valley Hall effect in MoS2/WTe2 heterobilayers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jekwan Lee ◽  
Wonhyeok Heo ◽  
Myungjun Cha ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantitative Information ◽  
Exciton Energy ◽  
Electron Hole ◽  
Kerr Rotation ◽  
Polarized Electrons ◽  
Spatially Resolved ◽  
Long Valley ◽  
Bound Electron ◽  
Valley Hall Effect

AbstractThe valley Hall effect (VHE) in two-dimensional (2D) van der Waals (vdW) crystals is a promising approach to study the valley pseudospin. Most experiments so far have used bound electron-hole pairs (excitons) through local photoexcitation. However, the valley depolarization of such excitons is fast, so that several challenges remain to be resolved. We address this issue by exploiting a unipolar VHE using a heterobilayer made of monolayer MoS2/WTe2 to exhibit a long valley-polarized lifetime due to the absence of electron-hole exchange interaction. The unipolar VHE is manifested by reduced photoluminescence at the MoS2 A exciton energy. Furthermore, we provide quantitative information on the time-dependent valley Hall dynamics by performing the spatially-resolved ultrafast Kerr-rotation microscopy; we find that the valley-polarized electrons persist for more than 4 nanoseconds and the valley Hall mobility exceeds 4.49 × 103 cm2/Vs, which is orders of magnitude larger than previous reports.

Investigation of the energy spectra and the electron–hole alignment of the InAs/GaAs quantum dots with an ultrathin cap layer

2016 ◽  
Vol 240 ◽  
pp. 20-23 ◽  
Author(s):  
Alexey P. Gorshkov ◽  
Natalia S. Volkova ◽  
Leonid A. Istomin ◽  
Anton V. Zdoroveishev ◽  
Sergey Levichev
Keyword(s):  
Quantum Dots ◽  
Energy Spectra ◽  
Electron Hole ◽  
Cap Layer

Multiple-branch exciton energy spectra in the FQHE regime

1995 ◽  
Vol 93 (3) ◽  
pp. 193-196 ◽  
Author(s):  
Vadim M. Apalkov ◽  
Emmanucl I. Rashba
Keyword(s):  
Energy Spectra ◽  
Exciton Energy

Influence of Exciton Gas and Electron—Hole Plasma on Exciton Energy Levels

1980 ◽  
Vol 100 (1) ◽  
pp. 215-226 ◽  
Author(s):  
G. Röpke ◽  
T. Seifert ◽  
H. Stolz ◽  
R. Zimmermann
Keyword(s):  
Energy Levels ◽  
Exciton Energy ◽  
Electron Hole ◽  
Hole Plasma ◽  
Electron Hole Plasma

REFRACTIVE PROPERTIES OF MOLECULAR CRYSTALLINE SUPERLATTICES

2013 ◽  
Vol 22 (03) ◽  
pp. 1350028 ◽  
Author(s):  
SINIŠA M. VUČENOVIĆ ◽  
BLANKA ŠKIPINA ◽  
TAINA GRUJIĆ ◽  
JOVAN P. ŠETRAJČIĆ
Keyword(s):  
Electromagnetic Field ◽  
Energy Transfer ◽  
Theoretical Study ◽  
External Electromagnetic Field ◽  
Energy Spectra ◽  
Refractive Indices ◽  
Exciton Energy ◽  
Specific Behavior ◽  
Dispersion Law ◽  
Two Parameters

In this paper, we continue the theoretical study of changes in optical characteristics of superlattices as a consequence of some specific behavior of excitons. Based on the particular dispersion law and the spectral distribution of excitons, we have formulated and calculated the refractive indices of these structures and defined how refractive indices change with external electromagnetic field. It was determined that among wide variety of parameters governing calculus, only two parameters have a significant effect on exciton energy spectra and calculated optical quantities: (a) the number of film layers which constitute superlattice; (b) ratio of the exciton energy transfer between the layers of one film and on the boundary between two different films.

scholarly journals Влияние распределения волновой функции на диссоциацию экситонов в электрическом поле

2018 ◽  
Vol 60 (8) ◽  
pp. 1495 ◽  
Author(s):  
J. Heckotter ◽  
M. Freitag ◽  
D. Frohlich ◽  
M. Abmann ◽  
M. Bayer ◽  
...  
Keyword(s):  
Electric Field ◽  
State Energy ◽  
Principal Quantum Number ◽  
Tunnel Barrier ◽  
Exciton Energy ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
Dissociation Threshold ◽  
Potential Landscape ◽  
Bound Electron

AbstractWe show that the dissociation threshold of an exciton, a bound electron-hole pair, by an electric field is mainly determined by its energy: as expected, the dissociation voltage decreases with increasing exciton energy. However, within the multiplet of states belonging to a particular principal quantum number n , the dissociation voltage rises with increasing state energy, in contrast to the expectations based on energy arguments. This behavior is demonstrated for the yellow exciton states of Cu_2O and is attributed to the distribution of the wavefunction in the potential landscape, where the lower (higher) lying state in the multiplet is shifted away (towards) the tunnel barrier.

scholarly journals Exciton energy spectra in polyyne chains

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Stella Kutrovskaya ◽  
Sevak Demirchyan ◽  
Anton Osipov ◽  
Stepan Baryshev ◽  
Anton Zasedatelev ◽  
...  
Keyword(s):  
Energy Spectra ◽  
Exciton Energy

Electron and exciton energy spectra in self-assembled InGaAs/GaAs ring-like nanostructures

2008 ◽  
Vol 245 (12) ◽  
pp. 2657-2661 ◽  
Author(s):  
V. M. Fomin ◽  
V. N. Gladilin ◽  
J. T. Devreese ◽  
N. A. J. M. Kleemans ◽  
M. Bozkurt ◽  
...  
Keyword(s):  
Energy Spectra ◽  
Exciton Energy ◽  
Self Assembled

Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.

A correlation of CL emissions from Penrith sandstone with elemental distributions obtained by simultaneous SEM-CL and EDS analysis

1995 ◽  
Vol 53 ◽  
pp. 392-393
Author(s):  
Paul J. Wright
Keyword(s):  
Optical Microscope ◽  
Electron Gun ◽  
High Electron ◽  
Collection System ◽  
Electron Hole ◽  
Depositional Processes ◽  
Eds Analysis ◽  
Distribution Mapping ◽  
Backscattered Electron ◽  
Electron Imaging

Most industrial and academic geologists are familiar with the beautiful red and orange cathodoluminescence colours produced by carbonate minerals in an optical microscope with a cold cathode electron gun attached. The cement stratigraphies interpreted from colour photographs have been widely used to determine the post depositional processes which have modified sedimentary rock textures.However to study quartzose materials high electron densities and kV's are necessary to stimulate sufficient emission. A scanning electron microscope with an optical collection system and monochromator provides an adequate tool and gives the advantage of providing secondary and backscattered electron imaging as well as elemental analysis and distribution mapping via standard EDS/WDS facilities.It has been known that the incorporation of many elements modify the characteristics of the CL emissions from geological materials. They do this by taking up positions between the valence and conduction band thus providing sites to assist in the recombination of electron hole pairs.

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