Terahertz spectroscopy of ultrafast carrier dynamics in nanomaterials

We use time-resolved terahertz spectroscopy to explore ultrafast carrier dynamics, transport, and localization in photoexcited nanocrystalline silicon films. The measured terahertz conductivity reveals a transition from free to localized behavior as the amount of disorder in the film increases, which is well-described within the framework of the Drude-Smith model.