2006 Participants
< Back
         
 

Justin Angus

Justin is only 2 classes away from his Math degree and 3 classes away from a Physics degree. The two necessary subjects required for his research topic are Differential Equations and Quantum Mechanics. He has received the highest marks in both classes and he does private tutoring for both subjects. By the end of Spring 2006 semester, Justin had accumulated almost 40 hours of Tutoring in Differential Equations and almost 30 hours of tutoring for Quantum Mechanics.

"Researchers are looking for materials with better optical-electrical properties. Recently organic-inorganic heterostructures have been produced. One example of these heterostructures is an inorganic quantum dot coated with an organic material. At the interface of this configuration a phenomenon occurs, that is known as hybrid excitation, when the energies of the Frenkel excitons (found in the organic layer) and the Wannier-Mott excitons (found in the quantum dot) are at or near resonance.

Excitons are very important because they control all of the optical transitions around the bandgap. This hybrid exciton is interesting because it has all the strengths of the two separate excitons, and none of their limitations. It has a high oscillator strength (characteristic of the Frenkel exciton) and a large exciton radius (characteristic of the Wannier-Mott exciton). A high oscillator strength is important because that means that the exciton will have a high probability of transitioning from one energy state to another, and the large exciton radius is important because that means that the exciton will be tunable by confinement affects (such as quantum confinement or magnetic confinement). These two traits seem to compliment each other and lead to another interesting feature. The hybrid exciton also has a very high optical nonlinearity. A high optical nonlinearity is a characteristic of the Frenkel exciton, but the hybrid excitons have been shown to have an increase in the optical nonlinearity of about five fold that found in the Frenkel exciton. A large optical nonlinearity means that this hybrid exciton will have a very high response to the absorbed photons. All of these traits in one exciton make this heterostructure very interesting for the improvement of optical-electrical devices.

So it is very important to study all of the properties of this hybrid exciton, as well as how it will be affected by external fields, such as a magnetic one. It is thought that a magnetic field would alter the symmetry of this heterostructure and lead to more complicated binding energies, thus it is thought that it will be possible to tune the bandgap just by manipulating a magnetic field around the heterostructure. This is very important in application where we need the device to work at some specific region of energy and wave vector. 

My job this summer was to theoretically research how the energies and other properties of this hybrid exciton will be affected by a magnetic field and my goals are to determine a wave function and energy curve dependent upon a magnetic field for the hybrid exciton"

 

     
 
 

.

.

.

.

.

.