Intrinsic free carrier mobility of quantum wells in polar materials

2005 ◽  
Vol 72 (12) ◽  
Author(s):  
J-L. Farvacque ◽  
F. Carosella
Keyword(s):  
Quantum Wells ◽  
Carrier Mobility ◽  
Free Carrier ◽  
Polar Materials

The intrinsic free carrier mobility in AlGaN/GaN quantum wells

2004 ◽  
Vol 831 ◽  
Author(s):  
F. Carosella ◽  
M. Germain ◽  
J.-L. Farvacque
Keyword(s):  
Quantum Wells ◽  
Carrier Mobility ◽  
Electron System ◽  
Relaxation Mechanism ◽  
Free Carrier ◽  
Free Carriers ◽  
Scattering Mechanisms ◽  
Carrier Interaction ◽  
Scattering Strength ◽  
Two Bodies

ABSTRACTThe aim of this contribution is to determine theoretically the maximum mobility that can be expected in AlGaN/GaN quantum wells as soon as the free carriers are only submitted to intrinsic scattering mechanisms associated with phonons and the carrier-carrier interaction. In our model, we consider that the carrier-carrier two bodies collisions do not constitute by themselves a relaxation mechanism since they conserve the momentum and the energy of the electron system. Thus, we assume that the free carriers act only through their contribution to the dynamical dielectric response of the material and, at least, through their collective behavior resulting into plasmons which, when damped, constitute now a real relaxation mechanism. The full scattering strength is connected with the imaginary part of the total reversed dielectric function including the lattice and the free carrier contributions. This approach automatically includes the scattering mechanisms associated with hybrid phonon/plasmon particles.

Free carrier mobility in AlGaN/GaN quantum wells

2002 ◽  
Vol 14 (48) ◽  
pp. 13319-13328 ◽  
Author(s):  
J-L Farvacque ◽  
Z Bougrioua ◽  
F Carosella ◽  
I Moerman
Keyword(s):  
Quantum Wells ◽  
Carrier Mobility ◽  
Free Carrier

ELECTRICAL AND OPTICAL PROPERTIES OF MULTILAYER SOL GEL ZnO COATINGS

2006 ◽  
Vol 20 (23) ◽  
pp. 3357-3364 ◽  
Author(s):  
TALAAT MOUSSA HAMMAD
Keyword(s):  
Carrier Mobility ◽  
Sol Gel ◽  
Dip Coating ◽  
Free Carrier ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
Zinc Oxide Films ◽  
Free Carrier Density ◽  
Fine Microstructure

Multilayer transparent conducting zinc oxide films have been prepared on boro-silicate substrates by the commercially sol gel dip coating process. Each layer was fired at 550°C in a conventional furnace for 15 min. The final coatings were then tempered under a flux of forming gas ( N 2/ H 2) at 400°C for 2 h. The coatings were characterized by surface stylus profiling and optical spectroscopy (UV-NIR). Results show that (1) ZnO films with electrical resistivity of 6×10-4 Ω· cm , free carrier mobility of approximately 77 cm 2/ V · s and free carrier density of approximately 6.14×1019 cm -3 are obtained for multilayers 310 nm and (2) the transmittance is approximately 60.4% and the reflectance is nearly 34.7% are obtained at a wavelength of 800 nm when the thickness of the ZnO multilayers is 310 nm. The crystal structure and grain orientation of ZnO films were determined by X-ray diffraction. SEM investigations revealed that the surface morphology of growing ZnO films on boro-silicate substrate is dominated by the smooth surface with a fine microstructure.

scholarly journals Electron mobility dependence on neutron irradiation fluence in heavily irradiated silicon

2021 ◽  
Vol 61 (2) ◽  
Author(s):  
J.V. Vaitkus ◽  
A. Mekys ◽  
Š. Vaitekonis
Keyword(s):  
Neutron Irradiation ◽  
Electron Mobility ◽  
Carrier Mobility ◽  
Carrier Transport ◽  
Radiation Detector ◽  
Forward Bias ◽  
Free Carrier ◽  
Detector Efficiency ◽  
Applied Model ◽  
Carrier Scattering

An increase of neutron irradiation fluence caused a decrease of Si radiation detector efficiency that was exceptionally well seen at 1017 neutron/cm2 fluence when the observed I–V characteristic of p-n junction under forward bias and under reverse bias became similar. Therefore the investigation of free carrier mobility could be a key experiment to understand the change of heavily irradiated silicon. The electron mobility was investigated by magnetoresistance means in microstrip silicon samples at temperature range T = 200–276 K. The analysis included the free carrier scattering by phonons, ionized impurities, dipoles and clusters and a contribution of each process was found by fitting the mobility dependence on temperature. The analysis of experimental data clearly demonstrated that the applied model did not explain the mobility in the samples irradiated to the highest fluence. Therefore a new concept of carrier transport is needed, and, as a conclusion, it could be stated that Si irradiated above 1016 cm–2 fluence (and up to 1020 cm–2) is a disordered material with the clusters.

Excitons and Free Carrier Lasing in II-VI Quantum Wells

1995 ◽  
Vol 182-184 ◽  
pp. 341-348
Author(s):  
E. Cingolani ◽  
L. Calcagnile ◽  
P. Prete ◽  
D. Greco ◽  
P.V. Giugno ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Free Carrier

Free-carrier screening of the interaction between excitons and longitudinal-optical phonons inInxGa1−xAs-InP quantum wells

1987 ◽  
Vol 35 (11) ◽  
pp. 5925-5928 ◽  
Author(s):  
M. S. Skolnick ◽  
K. J. Nash ◽  
P. R. Tapster ◽  
D. J. Mowbray ◽  
S. J. Bass ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Longitudinal Optical ◽  
Carrier Screening ◽  
Free Carrier ◽  
Optical Phonons

Phonons and Free Carriers in a Strained Hexagonal GaN-AlN Superlattice Measured by Infrared Ellipsometry and Raman Spectroscopy

1999 ◽  
Vol 595 ◽  
Author(s):  
M. Schubert ◽  
A. Kasic ◽  
T.E. Tiwald ◽  
J.A. Woollam ◽  
V. Harle ◽  
...  
Keyword(s):  
Carrier Mobility ◽  
Free Carrier ◽  
Phonon Modes ◽  
Lateral Mobility ◽  
Free Carriers ◽  
Organic Vapor ◽  
Infrared Ellipsometry ◽  
Order Of Magnitude ◽  
Metal Organic ◽  
Vertical Mobility

AbstractPhonon and free-carrier effects in a strained hexagonal (α) {GaN}l-{AlN}m superlattice (SL) heterostructure (l = 8 nm, m = 3 nm) are studied by infrared spectroscopic ellipsometry (IRSE) and micro (µ)-Raman scattering. Growth of the heterostructures was performed by metal-organic vapor phase epitaxy (MOVPE) on (0001) sapphire. An unstrained 1 µm-thick α-GaN layer was deposited prior to the SL. SL phonon modes are identified combining results from both IRSE and µ-Raman techniques. The shift of the GaN-sublayer phonon modes is used to estimate an average compressive SL stress of σxx ∼ - 4.3 GPa. The IRSE data reveal a free-carrier concentration of ne ∼ 5×1018 cm−3 within the undoped SL GaN-sublayers. According to the vertical carrier confinement, the free-carrier mobility is anisotropic, and the lateral mobility ( µ⊥ ∼ 400 cm2/Vs, polarization E⊥c-axis) exceeds the vertical mobility (µ∥ ∼ 24 cm2/Vs, E∥c) by one order of magnitude.

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