Photoionization cross-section of isotropic defects or impurity centers in isolators
1 Departamento de Física, Universidade Federal de Sergipe - 49100-000 São Cristóvão, SE, Brazil
2 Centro Multidisciplinar de Luís Eduardo Magalhães, Universidade Federal do Oeste da Bahia 47850-000 Luís Eduardo Magalhães, BA, Brazil
Received: 15 June 2016
Accepted: 16 August 2016
An analytical expression to calculate the photoionization cross-section of isotropic defects or impurity centers is being proposed by using the time-dependent perturbation theory. The ground-state wave function of the electron captured in the impurity state is described by a three-dimensional isotropic harmonic oscillator and the electron excited state in the continuum conduction band is described by a plane wave. The expression has been obtained considering all multipoles terms in the Hamiltonian, and that the radiation field which interacts with electrons is semi-classical and linearly polarized. This approximation is assumed because the effects of the linear contribution are dominant. The available data of the Al2O3:C and Lu2SiO5:Ce systems are in good agreement with our predictions. Such satisfactory comparison is a strong indication that the present model can be used to provide good predictions of the photoionization cross-section in several areas.
PACS: 34.90.+q – Other topics in atomic and molecular collision processes and interactions (restricted to new topics in section 34) / 34.10.+x – General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.)
© EPLA, 2016