Ultrafast carrier dynamics near a Si surface: a reflective transient grating study

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.