Hydrodynamic approach for modelling transport in quantum well device structures

A semiclassical approach for modelling electron transport in quantum well structures is presented. The model is based on the balance equations governing the conservation of particle density, momentum and energy with Monte Carlo (MC) generated transport parameters. Three valleys of the conduction band, size quantization in the Gamma valley, and the lowest two subbands in the quantum well are considered by taking the detailed intersubband dynamics into account. The transport parameters of the model are extracted from steady-state MC simulations based on an improved formulation of two-dimensional polar optical phonon scattering including screening effects. The predictions of the proposed model have been found to be in excellent agreement with those of the ensemble MC simulations under both time varying and spatially nonuniform fields. The calculated transport parameters which are of interest for device modelling are presented as a function of the electron energy for the AlGaAs/GaAs quantum well. The model serves as an accurate semiclassical alternative to costly ensemble MC simulations for studying the transport in quantum well structures and for the modelling and optimization of submicron devices based on these structures, such as modulation doped field-effect transistors (MODFETs).


Excitonic effects on the nonlinear optical properties of small quantum dots
KARABULUT, İBRAHİM; Safak, H.; Tomak, Mehmet (IOP Publishing, 2008-08-07)
The excitonic effects on the nonlinear optical properties of small quantum dots with a semiparabolic confining potential are studied under the density matrix formalism. First, within the framework of the strong confinement approximation, we present the excitonic states and then calculate the excitonic effects on the nonlinear optical properties, such as second harmonic generation, third harmonic generation, nonlinear absorption coefficient and refractive index changes. We find the explicit analytical expres...
Assessment of InSb photodetectors on Si substrates
Ozer, S; Beşikci, Cengiz (IOP Publishing, 2003-03-07)
We present the detailed characteristics of small area (33 x 33 mum(2)) InSb photodiodes grown on GaAs coated Si substrates by molecular beam epitaxy. In spite of very large lattice mismatch, 80 K peak detectivity of similar to1 x 10(10) cm Hz(1/2) W-1 has been measured under backside illumination without anti-reflection coating. Differential resistance at 80 K is limited by Ohmic leakage under small reverse bias and trap assisted tunnelling (TAT) under moderately large reverse bias. In the temperature range...
Molecular-dynamics simulations of surface and bulk properties of Zn, Cd, and ZnCd systems
Amirouche, L; Erkoç, Şakir (Wiley, 2004-02-01)
Surface and bulk properties of Zn, Cd, and ZnCd systems have been investigated by performing molecular-dynamics simulations using a recently developed empirical many-body potential energy function for these systems, which comprices two- and three-body atomic interactions. Surface reconstruction and multilayer relaxation on clean surfaces, adatom on surface, substitutional atom on surface and bulk materials, and vacancy on surface and bulk materials have been studied extensively. (C) 2004 WILEY-VCH Verlag Gm...
Perturbation analysis of sheath evolution, with application to plasma source ion implantation
Bektursunova, RM; Demokan, O (IOP Publishing, 2001-02-07)
A perturbation model has been developed to describe the evolution of an expanding plasma sheath around a cathode after a high-voltage negative pulse is applied to the cathode, simulating the conditions in devices such as those used for plasma source ion implantation. The set of governing equations consists of two coupled collisionless fluid equations for ions, and Poisson's equation and Boltzmann's assumption for electrons. The time-dependent, self-consistent expressions for the potential, ion density and i...
Phase Identification of La-Doped Hard Magnetic Barium Ferrite Using Artificial Neural Network
Sozeri, Huseyin; KÜÇÜK, İLKER; Ozkan, Husnu (Springer Science and Business Media LLC, 2011-01-01)
A model based on an artificial neural network (ANN) was designed for the simulation and estimation of 2 theta and intensity values obtained by X-Ray Diffraction (XRD) of pure and La-doped barium ferrite powders which have been synthesized in ammonium nitrate melt. Its performance is evaluated by the influences of different La content, sintering temperature, Fe/Ba ratio, and washed in HCl (or not washed in HCl) samples. The XRD patterns of samples estimated by the ANN agree well with the experimental values,...
Citation Formats
C. Beşikci and O. Sen, “Hydrodynamic approach for modelling transport in quantum well device structures,” JOURNAL OF PHYSICS D-APPLIED PHYSICS, pp. 2211–2218, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47552.