Department of Physics
Condensed Matter Seminar

The key in increasing the usage of energy conversion materials is to increase energy conversion efficiency and reduce cost/watt. Recently, there are significant progresses in developing highly efficient energy conversion materials, including thermoelectric and photovoltaic materials which are a result of the discoveries and progresses in nanoscience and nanotechnology. In our laboratory, we carry out fundamental studies on energy conversion and transfer processes. We use an ultrafast laser-based coherent phonon spectroscopy technique to investigate phonon vibration and interactions among energy carriers at the ultrafast time scale. This technique has femtosecond time resolution, capable of measuring atomic vibrations which typically have oscillation periods of the order of hundreds of femtoseconds. We applied this technique to investigate phonon dynamics in thin films, superlattices, and other types of energy conversion materials is which thermal transport and/or heat generation need to be enhanced or suppressed. With our new experimental techniques, it will be possible to investigate detailed energy conversion and transport processes that will help to design efficient energy conversion materials.