Mobility Overshoot of Hot Electrons
We consider the question of how the evolution of the nonequilibrium state of a highly photoexcited plasma in polar semiconductors (HEPS) affects the mobility of the hot carriers (photoinjected electrons and holes). For that purpose we resort to the use of the nonequilibrium statistical operator method (NSOM) in Zubarev’s approach , in the form already applied to the study of ultrafast relaxation phenomena in HEPS . A nonlinear transport theory follows from the NSOM, which allows to write down the equations of evolution for a basis set of nonequilibrium thermodynamic variables appropriate for the description of the macroscopic state of physical systems arbitrarily away from equilibrium. For the case of a HEPS in the presence of an electric field S , we choose the quasi-temperatures of carriers, T C * (t), and of the different phonon branches, T LO * (t), T TO * (t), T A * (t), the quasi-chemical potentials of electrons, μe(t), and of holes, μh(t), as well as the drift velocities ve(t) and vh(t). The concentration of photoinjected carriers, n, is taken as a constant, since recombination is negligible in the ps time scale we are considering.
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- 1.D.N. Zubarev, Neravnovesnaia Tennodinamika Statischekaia (Izd. Nauka, Moskwa, 1970)[English Transl.: Nonequilibrium Statistical Thermodynamics (Consultants Bureau, New York, 1974)]Google Scholar
- 2.A.C. Algarte and R. Luzzi, Phys. Rev. B27, 7563 (1983);Google Scholar
- R. Luzzi and A.R. Vasconcellos, in Semiconductors Probed by Ultrafast Laser Spectroscopy, Vol. I, ed. by R.R. Alfano (Academic, New York, 1984 ).Google Scholar