Confined and interface polar optical phonon-limited electron mobility in quantum wires

2005 ◽  
Vol 242 (7) ◽  
pp. 1482-1490 ◽  
Author(s):  
Arshak L. Vartanian
Keyword(s):  
Optical Phonon ◽  
Electron Mobility ◽  
Quantum Wires ◽  
Polar Optical Phonon

POLAR-OPTICAL PHONON-LIMITED ELECTRON MOBILITY IN QUANTUM WIRES

2006 ◽  
Vol 20 (21) ◽  
pp. 3015-3025 ◽  
Author(s):  
ARSHAK L. VARTANIAN
Keyword(s):  
Optical Phonon ◽  
Electron Mobility ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Dielectric Medium ◽  
Polar Optical Phonon ◽  
Wire Radius ◽  
Phonon Confinement ◽  
Intersubband Transitions ◽  
Low Field

The electron mobility conditioned by confined and interface polar-optical phonons for a quasi-one-dimensional cylindrical quantum wire embedded in a dielectric medium is investigated analytically. It is shown that the inclusion of the polar optical phonon confinement effects is crucial for accurate calculation of the low-field electron mobility in quantum wire. Taking into account the inelasticity of the electron-polar optical phonon interaction, the electron mobility is derived by a method which was successfully applied in three- and quasi-two-dimensional cases. The contribution of intersubband transitions to electron mobility for the Cd 0.35 Zn 0.65 Se quantum wire embedded in the CdZn dielectric medium is estimated. The extremums on the mobility dependences on wire radius and Cd concentration are obtained.

scholarly journals Determination of the LO phonon energy by using electronic and optical methods in AlGaN/GaN

Open Physics ◽  
2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Ozlem Celik ◽  
Engin Tiras ◽  
Sukru Ardali ◽  
Sefer Lisesivdin ◽  
Ekmel Ozbay
Keyword(s):  
Raman Spectroscopy ◽  
Hall Effect ◽  
Optical Phonon ◽  
Electron Mobility ◽  
Phonon Scattering ◽  
Impurity Scattering ◽  
Interface Roughness ◽  
Polar Optical Phonon ◽  
Optical Phonon Scattering ◽  
Hall Effect Measurements

AbstractThe longitudinal optical (LO) phonon energy in AlGaN/GaN heterostructures is determined from temperature-dependent Hall effect measurements and also from Infrared (IR) spectroscopy and Raman spectroscopy. The Hall effect measurements on AlGaN/GaN heterostructures grown by MOCVD have been carried out as a function of temperature in the range 1.8-275 K at a fixed magnetic field. The IR and Raman spectroscopy measurements have been carried out at room temperature. The experimental data for the temperature dependence of the Hall mobility were compared with the calculated electron mobility. In the calculations of electron mobility, polar optical phonon scattering, ionized impurity scattering, background impurity scattering, interface roughness, piezoelectric scattering, acoustic phonon scattering and dislocation scattering were taken into account at all temperatures. The result is that at low temperatures interface roughness scattering is the dominant scattering mechanism and at high temperatures polar optical phonon scattering is dominant.

Analytical Theory of Electron Mobility and Drift Velocity in GaN

1996 ◽  
Vol 449 ◽  
Author(s):  
B. L. Gelmont ◽  
M. S. Shur ◽  
M. Stroscio
Keyword(s):  
Electric Fields ◽  
Drift Velocity ◽  
Optical Phonon ◽  
Electron Mobility ◽  
Phonon Scattering ◽  
Electron Gas ◽  
Transport Equations ◽  
Polar Optical Phonon ◽  
Two Dimensional ◽  
Optical Phonon Scattering

ABSTRACTWe derive balance transport equations for the electron mobility and drift velocity, which are applicable at any degeneracy of the electron gas. These equations account for the polar optical phonon scattering and ionized impurity scattering and include the effects of screening. These equations are valid only for very high concentrations (above 1019 cm-3 for GaN). However, the comparison with the results of Monte Carlo simulations shows that they fairly accurately reproduce the field-velocity curves in GaN in moderate electric fields (up to 100 kV/cm). The comparison with the electron mobility calculated using the two-step model [1] shows a much larger difference but allows us to illustrate the trends in mobility dependencies caused by electron-electron collisions. We also derive the balance transport equations accounting for the polar optical phonon scattering in a two-dimensional electron gas. The calculations based on these equations, show that the unscreened polar optical scattering mobility is smaller in the two-dimensional gas than in the bulk intrinsic semiconductor and that the mobility decreases with the decrease of the quantum well thickness.

Polar Optical Phonon Instability and Intervalley Transfer in Gallium Nitride

1998 ◽  
Vol 512 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. O'leary ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
B. L. Gelmont ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Analytical Model ◽  
Optical Phonon ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Polar Optical Phonon ◽  
Scattering Mechanism ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Optical Phonon Scattering

ABSTRACTWe develop a simple, one-dimensional, analytical model, which describes electron transport in gallium nitride. We focus on the polar optical phonon scattering mechanism, as this is the dominant energy loss mechanism at room temperature. Equating the power gained from the field with that lost through scattering, we demonstrate that beyond a critical electric field, 114 kV/cm at T = 300 K, the power gained from the field exceeds that lost due to polar optical phonon scattering. This polar optical phonon instability leads to a dramatic increase in the electron energy, this being responsible for the onset of intervalley transitions. The predictions of our analytical model are compared with those of Monte Carlo simulations, and are found to be in satisfactory agreement.

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