Ultrafast and magneto-optical spectroscopy of semiconductor heterostructures
Noe, Gary Timothy, II
Master of Science
This thesis presents spectroscopic results using semiconductor heterostructures important for both applied and fundamental physics. First, we studied short-period superlattices of InAs and GaSb that suggest a promising alternative to mercury cadmium telluride for mid-infrared detection. Our time-domain measurements help sample growers optimize growth conditions to maximize the carrier lifetime and determine the superlattice period and interface quality. The second area of research has a more fundamental focus. Here, we study the time-integrated emission and time-resolved population and emission properties of high-density excitons in an InGaAs quantum well sample in strong perpendicular magnetic field. Our time-integrated results indicate that two-dimensional magneto-excitons can appear to be stable against a Mott transition with the application of magnetic field. Our time-resolved results provide the first direct observation of superfluorescence using a semiconductor showing the population inversion of magneto-excitons suddenly drop from fully excited to completely unexcited emitting an intense pulse of coherent radiation.
Applied sciences; Pure sciences; Condensed matter physics; Optics; Materials science