Our research focuses on three areas in chemical dynamics and spectroscopy: (i) studies of reaction dynamics through a combination of transition state spectroscopy with state-resolved photodissociation experiments on stable molecules and reactive free radicals, (ii) size-dependent spectroscopy and dynamics of semiconductor clusters, and (iii) the effect of clustering and solvation on fundamental chemical processes. Novel experiments involving photodetachment of negative ion beams have been developed to address several of these issues. For example, the transition state spectroscopy of isolated reactions and reactions in clusters is studied by photodetachment and photoelectron spectroscopy of solvated transition state precursor anions. Femtosecond time-resolved photoelectron spectroscopy of negative ions is used to probe the effects of clustering on photodissociation and vibrational relaxation dynamics. We also perform experiments on neutral beams, and have recently set up an experiment in which the spectroscopy and dynamics of Rydberg states in doped helium nanodroplets is investigated with photoionization and photoelectron spectroscopy.
In the News
In semiconductors like silicon, electrons attached to atoms in the crystal lattice can be mobilized into the conduction band by light or voltage. Berkeley scientists have taken snapshots of this very brief band-gap jump and timed it at 450 attoseconds.