Ultrafast energy carrier (electrons, phonons, etc.) dynamics in nanoscale materials, particularly nano-engineered thermoelectric and photovoltaic materials for energy conversion applications. These studies employ an ultrafast laser pump-and-probe experimental facility to investigate energy transfer from photons to electrons to lattice heating. Coherent phonon excitation and detection are used to understand ultrafast interactions among energy carriers, scattering at interfaces and boundaries, and the relation between phonon dynamics and global energy transfer properties.  

Thermal properties measurements. We employ photoacoustic method and femtosecond thermal reflectance method to measure thermal conductivity of thin film and bulk materials. We have provided measurement services to industries, academic institutions, and government laboratories.  

Fundamentals of heat/energy transfer in ultrafast-laser materials interaction,including molecular dynamics simulation and ultrafast time-resolved measurements.