نتایج جستجو برای: electron relaxation time
تعداد نتایج: 2206802 فیلتر نتایج به سال:
The spin and phase coherence times of the itinerant electrons in n-InSb thin films were experimentally determined by analyzing the low-temperature magnetoresistance in antilocalization theory. The results indicate a very weak temperature dependence below 10 K for the spin coherence time. The dependence of the spin coherence time on carrier density demonstrates that the Elliott-Yafet mechanism i...
State-of-the-art time domain density functional theory and non-adiabatic (NA) molecular dynamic simulations are used to study phonon-induced relaxation of photoexcited electrons and holes in Ge and Si quantum dots (QDs). The relaxation competes with productive processes and causes energy and voltage losses in QD solar cells. The ab initio calculations show that quantum confinement makes the ele...
The electron relaxation times Tt and T2 have been measured by ESR pulse techniques in solutions of normal and perdeuterated (diphenyl)" in dimethoxyethane at various radical concentrations and temperatures. The results are discussed in terms of different relaxation mechanisms. The most important contribution to spin-lattice relaxation at high concentration is dipolar interaction with other radi...
In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings ("phonon-bottleneck"). However, excited-state relaxation was observed to...
The quantum interference between ‘pure’ electron–phonon and electron-boundary/impurity scattering drastically changes the electron–phonon relaxation rate. If impurities and boundaries vibrate in the same way as the host lattice, the electron–phonon relaxation rate is significantly decreased. In the presence of the scattering potential that does not vibrate with phonons (e.g. rigid boundaries, i...
We report theoretical study of the effects of energy relaxation on the tunneling current through the oxide layer of a two-dimensional graphene field-effect transistor. In the channel, when three-dimensional electron thermal motion is considered in the Schrödinger equation, the gate leakage current at a given oxide field largely increases with the channel electric field, electron mobility, and e...
[1] The optical emissions in a large number of bright sprites observed over one storm in 1998 exhibit a relaxation that is closely exponential in time. This feature was unexpected but might be explained by the presence of quasi-constant electric fields over times of several milliseconds, in which case the optical relaxation would be a direct indication of the exponentially changing electron den...
We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data o...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید