Dr. Heather Rypkema
Department of Chemistry
University of Louisville
Louisville, KY 40292
Phone: 502-852-1223
Email: heather.rypkema@louisville.edu
The goal of this project is to elucidate the time-dependent nature of photoinduced changes in isolated semiconductor and complete photoelectrochemical (PEC) systems. Individual kinetic timescales in PEC cells range from femtoseconds (10^-15 s) to seconds depending on the nature of the process under consideration. Central to this project is the Center for Transient Ultrafast Spectroscopy, a facility capable of monitoring changes in the visible spectrum of a sample (solid or liquid) subsequent to an ultrafast - 50-100 fs - pump pulse. The resulting data can be used to characterize electron injection rates and recombination rates, as well as identify the formation and decay times of transient species. By studying isolated photoresponse of material as well as the altered photoresponse at a variety of timescales, competing kinetic processes can be fully characterized, and potentially motivate the tailoring of material properties in order to maximize cell efficiency.
mehanna@engr.uky.edu