Date of Award


Degree Name



College of Science

Type of Degree


Document Type


First Advisor

Dr. Que Huong Nguyen, Committee Chairperson

Second Advisor

Dr. Maria Hamilton

Third Advisor

Dr. Sean McBride


In this thesis, we are studying the electronic structures and optical properties of charged excitons and trions (i.e., the exciton-associated quasi-particles in semiconductor materials) in quantum dots which have a three-dimensional confinement configuration. We also consider the effects of an external electric and magnetic field on the charged excitons. Initially theorized in 1958, charged excitons are a fairly new phenomenon in physics in which an exciton (i.e., an electron coupled with an electron hole) is coupled with either another electron or another hole (giving either a ‘negative exciton’ or ‘positive exciton’ accordingly). In the completely confined configuration like the quantum dots, the interaction between the excitons and the electron (or the electron hole) is strong due to the confinement. We have obtained the energies as well as the wave functions for the electronic states of the charged excitons. Using these results, we were able to find the energy splitting and the resulting states under the application of an external field. We have made the same calculations for the negative and positive trions and our results supported previous theoretical work which stated that charged excitons and trions are different quasi-particles. In order to understand more about the differences between these quasi-particles, in this work the electric and magnetic field effects and splitting of energy levels have been calculated for a negative exciton, negative trion, and positive trion structure inside a direct band gap semiconducting quantum dot. The respective wave functions of the resulting states for the negative and positive exciton and trions have also been obtained for the first time.



Quantum dots.


Exciton theory.