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Monte Carlo analysis of hot-phonon effects on non-polar semiconductor transport properties
No full textTransient hot-phonon effects on the velocity overshoot of GaAs: a Monte Carlo analysis
No full textA novel ensemble Monte Carlo algorithm has been developed to simulate nonequilibrium phonon effects in the transient and steady-state high-field conductivity of bulk n-GaAs. The interplay of the electronic intervalley transfer with the mutual drag and heating between the carriers and longitudinal optical phonons is demonstrated over a wide range of fields, temperatures and carrier densities.For the moderately high doping levels of practical interest the characteristic times for a strong phonon amplification turn out to be sufficiently long to prevent a substantial interference of phonon disturbances with the onset of valley transfer during overshoot, but modifications of up to 20 percent are found for the steady-state velocity, with a gradual change from an enhancement at low fields to a comparable decrease around the maximum and negative differential part of the velocity-field characteristics.Comparable nonequilibrium-phonon effects are found for the case of negligible (i.e. remote) ionized-impurity scattering as realized in various GaAs-based heterostructures
Monte Carlo analysis of hot-phonon effects on non-polar semiconductors transport properties
No full textAn iterative procedure to include phonon disturbance into a Monte Carlo algorithm is presented. Low temperature transport in p-Ge is considered. Calculations show that carrier drift velocity and mean energy increase as a result of the phonon amplification
Monte Carlo studies of nonequilibrium phonon effects in polar semiconductors and quantum wells. Part 2. Non ohmic transport in n-type Gallium Arsenide
No full textMonte Carlo studies of nonequilibrium phonon effects in polar semiconductors and quantum wells. I. Laser photoexcitation
No full textThe present paper illustrates a series of theoretical results on nonequilibrium phonon effects based on a novel Monte Carlo algorithm. The details of the numerical procedure are given. No assumptions on the form of the phonon or the electron distributions are required. The main emphasis is given to the study of LO-phonon perturbations as a result of the relaxation of photoexcited carriers in polar semiconductors. Bulk GaAs and InP, as well as GaAs-AlxGa1-xAs heterostructures are analyzed. Good agreement is found with available experimental results from time-resolved luminescence and Raman measurements. The strong phonon emission by the high-energy photoexcited electrons in the first stage of their relaxation (within a few tenths of a picosecond) is found to drive the phonon distribution strongly out of equilibrium. After the excitation, reabsorption of the emitted phonons by the carriers and nonelectronic phonon-decay processes bring the distribution back to its equilibrium value
Monte Carlo studies of nonequilibrium phonon effects inpolar semiconductors and quantum wells. Part 1. Laser photoexcitation
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Monte Carlo studies of nonequilibrium phonon effects in polar semiconductors and quantum wells. II. Non-Ohmic transport in n-type gallium arsenide
No full textEffects of LO-phonon disturbances on the transient and steady-state high–dc-field response of n-type gallium arsenide are studied by implementing the simulation of nonequilibrium phonon distributions into the conventional Monte Carlo algorithms for hot-carrier transport in semiconductors. Strong LO-phonon amplification is found for the whole range of fields, carrier densities, and temperatures of interest. At room temperature the phonon disturbances lead to enhancements of up to 20% of the steady-state velocity at low fields and to reductions of up to 10% for fields around and above the maximum of the velocity-field characteristics. However, detailed phase-space restrictions for LO-phonon reabsorption prevent a noticeable interference of the phonon buildup with the transient velocity overshoot
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