Reflective transient grating experiments were conducted using two different experimental configurations to study carrier dynamics. Using an 800 nm pump and 400 nm probe, a signal attributed to bleaching was observed, and the carrier energy relaxation time was measured to be approximately 600 fs. Experiments were also conducted with a 400 nm pump and 800 nm pump. For this configuration, the observed TG signal decay was attributed to carrier diffusion and recombination.
The second harmonic generation from pyridine multilayers adsorbed on Ag(111) has been studied for the elucidating the structure of the adsorbed layers. An irreversible phase transition in the pyridine overlayers was observed when the pyridine film/Ag crystal is annealed above approximately 145 K. The phase transition is speculated to be from the formation of ordered domains in the pyridine multilayers.
The dynamics of photocarrier diffusion was studied by a two color transient grating technique in reflection geometry. A single exponential decay feature was observed immediately following the electron excitation pulse and was attributed to band edge carrier diffusion.