James Heyman is interested in experimental condensed matter physics and ultrafast laser spectroscopy. Students regularly collaborate with him in his NSF-funded research on ultrafast processes in semiconductors and the generation of picosecond pulses of electromagnetic radiation.
Professor Heyman spent his recent sabbatical at Lawrence Berkeley National Laboratory in Berkeley, California. There he worked with scientists in the Materials Science Division to investigate novel materials for solar energy called intermediate band photovoltaics.
Intermediate band photovoltaics offer a path to increasing the efficiency of solar cells. In a solar cell, solar photons excite electrons in a semiconductor from the valence band to the conduction band.
In efficient solar cells, electrons must stay in the conduction band long enough to be collected. If they drop back down to the valance band too fast, the energy of the photon is lost. Heyman’s research at LBNL focused on measuring the excited state lifetimes in intermediate band photovoltaic materials.
PhD: University of California at Berkeley