Ultrafast time-resolved visible-pump, far-IR (THz) probe spectroscopy has been
developed in our lab and has been applied to study carrier dynamics in photoexcited
GaAs and dipole solvation dynamics in betaine and p-nitroaniline. This type of
spectroscopy enables us to study for the first time the nonequilibrium interaction
between excited electronic states and low frequency vibrational modes.
We explore ultrafast carrier dynamics and interactions of photoexcited carriers with lattice vibrational modes in BiVO4 using time-resolved terahertz spectroscopy and first-principles phonon spectrum calculations.