Photoionization cross-section of isotropic defects or impurity centers in isolators. (12th September 2016)

• Record Type: Journal Article
• Authors: Lima, H.; Batista, J. V.; Couto dos Santos, M. A.
• Is Part Of: Europhysics letters. Volume 115:Number 3(2016:Aug.)
• Publication Date: 2016-09-12
• Subjects: 34.90.+q -- 34.10.+x; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/115/33002
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: 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 Al2 O3 :C and Lu2 SiO5 :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.