Monte Carlo modeling of high-field transport in III-V heterostructures

Journal of Applied Physics

Dessenne

2005

108

A theoretical model of electron-electron scattering in multisubband systems is proposed and used to set up a Monte Carlo simulator of quantum cascade lasers. Special features of the electron-electron scattering model are the following: ͑i͒ A fast and accurate computation of bare potential matrix elements by means of Fourier analysis is developed. ͑ii͒ A screening model is proposed that allows us to describe intersubband matrix elements. ͑iii͒ Nonequilibrium screening factors, defined through an effective subband temperature for each subband, are periodically reevaluated. ͑iv͒ The developed algorithm makes use of rejection procedures in order to determine the correct number of scattering events as well as the distribution of the final states. Other characteristics of the model are the following: the energy levels and the wave functions are determined in a self-consistent way, the Pauli exclusion principle is included, and the periodicity of the structure is accounted for. This model is applied to the study of a terahertz resonant phonon quantum cascade laser. A large influence of the screening model on the subband population is demonstrated. For the considered design, emission at a frequency as low as 1 THz is confirmed. We have found that the magnitude of population inversion phenomena may be strongly sensitive to electron-electron scattering, reducing the possible performance near 1 THz.

Section: A General Features: Electronic Statesmentioning

confidence: 99%

Modeling of electron–electron scattering in Monte Carlo simulation of quantum cascade lasers

Bonno

Journal of Applied Physics

Dessenne

2005

108

“…Other features of the model are standard and have been extensively described in previous papers. 11,18,38 Let us recall them briefly here: ͑i͒ The electron states are calculated within the framework of envelope function theory accounting for a nonparabolic BenDaniel-Duke Hamiltonian. 18 ͑ii͒…”

Section: Monte Carlo Resultsmentioning

confidence: 99%

Monte Carlo modeling of carrier-carrier scattering in semiconductors with nonparabolic bands

Bonno

Journal of Applied Physics

2008

An efficient algorithm to account for nonparabolicity in carrier-carrier scattering in an ensemble Monte Carlo simulator is proposed. The major difficulty of modeling intercarrier scattering in semiconductors with nonparabolic bands arises from the two particle momentum and energy conservation laws that have to be simultaneously satisfied. A numerically efficient method is thus proposed to compute the final states accounting for a nonparabolic density of states and included in an ensemble Monte Carlo simulator. The developed algorithm makes use of rejection procedures in order to determine the correct number of scattering events as well as the distribution of the final states. This algorithm is then applied to compute constant-energy contours in various semiconductors, including narrow gap, highly nonparabolic materials, such as InAs. The model is also used to investigate the electron dynamics in an InAs quantum well heterostructure. Our results show that nonparabolicity significantly alters the transient regime since it increases the number of carrier-carrier scattering events. Finally, we investigate the validity of the parabolic approximation in the modeling of a typical GaAs resonant phonon terahertz quantum cascade laser. It is shown that, although electron-electron scattering plays a crucial role in setting the device performance of the laser, the effect of nonparabolicity in this interaction alters only slightly the population inversion while the subband temperatures are increased.

“…We take up to 100 subbands per valley and consider that electron states related to all valleys are quantized. This approach allows us to describe electron transport in a wide range of field without having to deal with 3D states and "2D-3D transfers" [9].…”

Section: Modelmentioning

confidence: 99%

Monte Carlo study of low and high-field electron transport in GaN-based heterostructures

2014 International Workshop on Computational Electronics (IWCE)

Dessenne

Dalle

2014

Self Cite

Electron transport properties of GaN-based heterostructures are investigated by means of a Monte Carlo model, which considers a large number of subbands in several valleys. Room-temperature low-field mobility consistent with experimental results is obtained provided that screening of phonon scattering is accounted for. In intrinsic heterostructures the mobility is always greater than in bulk GaN. Dislocations strongly reduce mobility at low electron density. Transport under applied field up to 300 kV/cm is also investigated. The peak velocity is found to decrease when electron density is increased