Eur. Phys. J. D (2021) 75: 110
https://doi.org/10.1140/epjd/s10053-021-00130-7

Regular Article – Atomic Physics

Oscillator strengths, transition probabilities and state lifetimes of on- and off-center donor impurities in quantum dots: off-center displacement, quantum size and potential-shape effects

¹ Department of Physics, Faculty of Sciences, University of Maroua, P. O. Box 814, Maroua, Cameroon
² College of Technology, University of Buea, P.O. Box 63, Buea, Cameroon
³ Laboratoire de Physique Fondamentale, UFD Mathématiques, Informatique Appliquée et Physique Fondamentale, University of Douala, P. O. Box 24157, Douala, Cameroon
⁴ Department of Physics, Higher Teacher Training College, University of Yaounde 1, P.O. Box 47, Yaounde, Cameroon

^b biglingui@gmail.com

Received: 6 December 2020
Accepted: 14 March 2021
Published online: 26 March 2021

Abstract

Nonrelativistic dipole matrix elements, oscillator strengths, transition probabilities and states lifetimes of quantum dots with centered and off-centered hydrogenic impurities are studied. The effects of the off-center displacement combined to the shape of the confining potential are investigated. These optical parameters are found to be strongly modified by the parameters characterizing the confinement as well as by taking into account of the off-center shift. It is found that the oscillator strengths present a minimum for certain values of the confinement potential range and of the off-center displacement, principally due to the reaching of a low energy gap between the levels involved in the concerned transition. Likewise, the states lifetimes increase with the off-center displacement whatever the shape of the confinement potential is because of the reduction of the gap between the energies of the states when the displacement is no longer equal to zero.