Model of thermalization of quasifree electrons in high-mobility liquids and its relationship with electron mobility

Abstract

The present paper aims at constructing a theoretical model in terms of which the relationship between the free-ion yield and electron mobility may be understood for high-mobility liquids. The framework chosen for that purpose is the Fokker-Planck equation with the Coulomb field of the electron and the sibling cation built into it. This equation describes, in general, the distribution function for the electrons in both the configurational and velocity spaces. Starting from a given initial position and velocity, one can calculate the distribution of thermalization distances through the use of a relaxation time. The same relaxation time appears in the mobility equation. implying the similarity of energy-loss processes of low-energy electrons following an ionization event and of electrons slightly heated up by the external field. The model therefore provides, in principle. a connection between the electron mobility and the free-ion yield. In practice the agreement between theory and experiment is reasonably good for molecular hydrocarbons but is poor for liquefied rare gases.

Thermalization of photoelectrons in polar medium

“…(5.7), implies that the deceleration of the charge is inversely proportional to its velocity. Consequently, the Langevin equation 32 does not constitute a proper macroscopic description of the dynamics (thermalization process) in this case.…”

“…There have been only a few attempts in the past to study thermalization theoretically. [31][32][33] Mozumder 32 have used the Langevin equation as a starting point of their analysis. They reduced the Fokker-Planck equation for the joint position-momentum distribution function to a closed set of differential equations, which was solved numerically (this method was extended by Silinsh et al 34 to include the external electric field).…”

On Charge Carrier Photogeneration Mechanisms in Organic Molecular Crystals

“…This "ballistic" model has been shown to be valid for the description of photogeneration processes in organic molecular crystals [2, 5 , 7 , 9 to 11, 13, 141, organic polymers [15], amorphous selenium [16, 171, as well as for the description of carrier generation by ionizing radiation in liquid and solid hydrocarbons (see e.g. [18,191).…”

“…An analytical treatment of the thermalization of epithermal electrons (Ek 5 1 eV) in liquid hydrocarbons has been proposed by Sano and Mozumder (SM) [18]. SM consider the hot electron as a Brownian particle having excess E, and radial velocity a, which the particle loses by creating phonons and working against the local Coulomb field.…”

Reorganization energies for charge transfer in carbazole compound containing trinitrofluorenone

“…There are many theories describing it [4][5][6][7]. The separation (recombination) stage is usually described by Onsager theory [8].…”