*****NON-TECHNICAL ABSTRACT***** As computers and other electronic devices become ever faster, it becomes increasingly important to understand the flow of electrical current in semiconductors and other electronic materials on time-scales shorter than a trillionth of a second. This grant will support a research project in ultrafast optics and semiconductor physics at Macalaster College, an undergraduate institution. Femtosecond light pulses will be used to excite bursts of current in semiconductors, the evolution of the current pulses in time will be studied by recording the "light" the pulses emit. The goal is to measure the electrical properties of a range of semiconductors and semiconductor structures on time scales that will be relevant to the development of electronic technology. The project will also provide undergraduates at Macalester College with hands-on training in Photonics and experimental Condensed Matter Physics.
This grant will support research in ultrafast optics and semiconductor physics at Macalester College. As switching rates in electronic devices are pushed to ever higher frequencies, it becomes increasingly important to understand carrier transport phenomena in semiconductors on picosecond and femtosecond time-scales. Using ultrafast terahertz spectroscopy it is possible to impulsively excite a semiconductor with a femtosecond optical pulse or single-cycle electromagnetic pulse, and record the resulting motion of charge in time. These techniques will be used to investigate the mobility and conductivity of photoexcited carriers in a range of semiconductor materials and heterostructures on time-scales that will be relevant to future devices. The project will also provide undergraduate research assistants at Macalester College with hands-on training in Photonics and experimental Condensed Matter Physics.