Kinetic model for electron tunneling in frozen irradiated systems

Abstract

A kinetic model for tunneling of the trapped electron e;-from its trap to a scavenger S has been developed. The probability of the transition of e ,-through the three-dimensional potential barrier has been calculated based on the theory of quasistationary states. The transparency of the barrier has been expressed in terms of (1) the distance e;--Sand (2) the energy level in the acceptor molecule. In order to calculate the kinetics of e;-decay. the distribution of e;--S distances, and the energy levels of electrons in the traps have been taken into account. The model has been numerically applied to the decay of electrons trapped in the glassy 8 M NaOH in the presence of NO] used as an electron acceptor. The presented model does not allow one to calculate the density of energy levels in the scavenger accesible to electron. Therefore, this parameter has been chosen to provide the best fit of the theory to the experimental data. The observed time dependence as well as scavenger concentration dependence are in a good agreement with those predicted by the theory.

On the UV contribution to plasma-induced luminescence of polypropylene

“…UV [4][5][6], γ [8][9][10] and x-ray [11][12][13][14][15][16][17] irradiation have all been reported to cause ionizing excitations leading to slow radiative recombination. There are essentially two kinds of physical process that have been proposed to explain such a behaviour: (i) diffusion models, as originally proposed by Debye and Edwards [4] and subsequently refined by several authors [18][19][20], and (ii) tunnelling models involving either a homogeneous or inhomogeneous distribution of cation-electron separation distances [10,16,[21][22][23]. Note that a power-law decay has been obtained, assuming an exponential distribution of trap depths and first-order kinetics [11].…”

Laser system with a regenerative amplifier for generation of trains of pulses of variable amplitude

“…UV [4][5][6], γ [8][9][10] and x-ray [11][12][13][14][15][16][17] irradiation have all been reported to cause ionizing excitations leading to slow radiative recombination. There are essentially two kinds of physical process that have been proposed to explain such a behaviour: (i) diffusion models, as originally proposed by Debye and Edwards [4] and subsequently refined by several authors [18][19][20], and (ii) tunnelling models involving either a homogeneous or inhomogeneous distribution of cation-electron separation distances [10,16,[21][22][23]. Note that a power-law decay has been obtained, assuming an exponential distribution of trap depths and first-order kinetics [11].…”

Electron tunneling in molecular solids. An orbital overlap model

“…al 32. have adapted the three-dimensional treatment of a decay to tunneling into a bound state using SSW wave functions, but most authors use a one-dimensional barrier-penetration model to describe long-range tunneling.…”