Experimental energy difference between heavy- or light-hole valence band and crystal-field split-off-hole valence band in AlxGa1−xN

2006 ◽  
Vol 89 (25) ◽  
pp. 251107 ◽  
Author(s):  
Hideo Kawanishi ◽  
Eiichiro Niikura ◽  
Mao Yamamoto ◽  
Shoichiro Takeda
Keyword(s):  
Valence Band ◽  
Crystal Field ◽  
Energy Difference ◽  
Light Hole ◽  
Experimental Energy

scholarly journals Valence Band Mixing in GaAs/AlGaAs Quantum Wells Adjacent to Self-Assembled InAlAs Antidots

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Valence Band ◽  
Energy Barrier ◽  
Heavy Hole ◽  
Electronic States ◽  
Light Hole ◽  
Photoluminescence Excitation ◽  
Band Mixing ◽  
Valence Band Mixing

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.

A Purely Spectroscopic Technique for Determining Energy Band Offsets in Quantum Wells

1991 ◽  
Vol 240 ◽  
Author(s):  
Emil S. Koteies
Keyword(s):  
Quantum Wells ◽  
Valence Band ◽  
Accurate Determination ◽  
Energy Difference ◽  
Spectroscopic Technique ◽  
Band Offsets ◽  
Band Energy ◽  
Semiconductor Quantum Wells ◽  
Sensitive Function

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.

Strong heavy-to-light hole intersubband absorption in the valence band of carbon-doped GaAs/AlAs superlattices

2013 ◽  
Vol 113 (5) ◽  
pp. 053103 ◽  
Author(s):  
M. I. Hossain ◽  
Z. Ikonic ◽  
J. Watson ◽  
J. Shao ◽  
P. Harrison ◽  
...  
Keyword(s):  
Valence Band ◽  
Light Hole ◽  
Carbon Doped ◽  
Intersubband Absorption

Direct observation of valence-band crystal-field splitting in CdSiAs2

1989 ◽  
Vol 71 (4) ◽  
pp. 307-309 ◽  
Author(s):  
G.A. Medvedkin ◽  
Yu.V. Rud' ◽  
M.A. Tairov
Keyword(s):  
Valence Band ◽  
Crystal Field ◽  
Direct Observation ◽  
Crystal Field Splitting ◽  
Field Splitting

An unconventional method for measuring the TcL3-edge of technetium compounds

2014 ◽  
Vol 21 (6) ◽  
pp. 1275-1281 ◽  
Author(s):  
Peter E. R. Blanchard ◽  
Emily Reynolds ◽  
Brendan J. Kennedy ◽  
Chris D. Ling ◽  
Zhaoming Zhang ◽  
...  
Keyword(s):  
Crystal Field ◽  
Direct Evidence ◽  
Energy Shift ◽  
Energy Difference ◽  
Crystal Field Splitting ◽  
Oxidation States ◽  
Field Splitting ◽  
Absorption Edge Energy ◽  
Powder Samples ◽  
Unconventional Method

TcL3-edge XANES spectra have been collected on powder samples of SrTcO3(octahedral Tc4+) and NH4TcO4(tetrahedral Tc7+) immobilized in an epoxy resin. Features in the TcL3-edge XANES spectra are compared with the pre-edge feature of the TcK-edge as well as other 4dtransition metalL3-edges. Evidence of crystal field splitting is obvious in the TcL3-edge, which is sensitive to the coordination number and oxidation state of the Tc cation. The TcL3absorption edge energy difference between SrTcO3(Tc4+) and NH4TcO4(Tc7+) shows that the energy shift at the TcL3-edge is an effective tool for studying changes in the oxidation states of technetium compounds. The TcL3-edge spectra are compared with those obtained from Mo and Ru oxide standards with various oxidation states and coordination environments. Most importantly, fitting the TcL3-edge to component peaks can provide direct evidence of crystal field splitting that cannot be obtained from the TcK-edge.

Valence Band Crystal Field Splitting of Hexagonal Diluted Magnetic Semiconductors

1994 ◽  
Vol 181 (2) ◽  
pp. 439-445 ◽  
Author(s):  
A. Twardowski ◽  
K. Chern-Yu ◽  
F. R. Chen ◽  
S. S. Kuo ◽  
C. S. Ro ◽  
...  
Keyword(s):  
Valence Band ◽  
Crystal Field ◽  
Diluted Magnetic Semiconductors ◽  
Magnetic Semiconductors ◽  
Crystal Field Splitting ◽  
Field Splitting ◽  
Diluted Magnetic

On the photoemission spectra of CoO: Crystal-field analyses of the valence band structure

1979 ◽  
Vol 62 (1) ◽  
pp. 125-130 ◽  
Author(s):  
G. Grenet ◽  
Y. Jugnet ◽  
Tran Minh Duc ◽  
M. Kibler
Keyword(s):  
Band Structure ◽  
Valence Band ◽  
Crystal Field ◽  
Valence Band Structure

Heavy-to-light hole intersubband absorption in the valence band of GaAs/AlAs heterostructures

2013 ◽  
Vol 1509 ◽  
Author(s):  
M. I. Hossain ◽  
Z. Ikonic ◽  
J. Watson ◽  
J. Shao ◽  
P. Harrison ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Valence Band ◽  
Diffusion Length ◽  
Careful Analysis ◽  
Light Hole ◽  
Intersubband Transitions ◽  
Intersubband Absorption ◽  
Solid Carbon Source ◽  
P Type ◽  
Theoretical Simulations

ABSTRACTWe performed a thorough investigation of mid-infrared heavy-to-light hole intersubband absorption in the valence band of p-doped GaAs quantum wells with AlAs barriers. For the p-type doping a high-purity solid carbon source was used. The experimental results are compared with theoretical simulations. The inclusion of layer inter-diffusion well reproduces the transition energies. We estimate a 6-10 Å inter-diffusion length that is consistent with electron microscopy measurements. A careful analysis of our results provides valuable information for further design of emitters and detectors based on hole intersubband transitions in the valence band.

Investigation of the valence band structure of PbSe by optical and transport measurement

2013 ◽  
Vol 1490 ◽  
pp. 75-81 ◽  
Author(s):  
Thomas C. Chasapis ◽  
Yeseul Lee ◽  
Georgios S. Polymeris ◽  
Eleni C. Stefanaki ◽  
Euripides Hatzikraniotis ◽  
...  
Keyword(s):  
Band Structure ◽  
Valence Band ◽  
Room Temperature ◽  
Heavy Hole ◽  
Light Hole ◽  
Band Model ◽  
Valence Band Structure ◽  
Effective Masses ◽  
Wide Range ◽  
Two Band Model

ABSTRACTWe investigated the valence band structure of PbSe by a combined study of the optical and transport properties of p-type Pb1-xNaxSe, with Na concentrations ranging from 0 – 4%, yielding carrier densities in a wide range of 1018 – 1020 cm−3. Room temperature infrared reflectivity studies showed that the susceptibility (or conductivity) effective mass m* increases from ∼ 0.06mo to ∼ 0.5mo on increasing Na content from 0.08% to 3%. The Seebeck coefficient scales with doping in the whole temperature range, yielding lower values for higher Na contents, while the Hall coefficient increases on heating from room temperature showing a peak close to 650 K. The room temperature Pisarenko plot is well described by the simple parabolic band model up to ∼ 1·1020 cm−3. In order to describe the behaviour in the whole concentration range, the application of the two band model, i.e. light hole and heavy hole, was used giving density of states effective masses 0.28mo and 2.5mo for the two bands respectively.

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