Femtosecond studies of electron dynamics at interfaces

A delocalized electron at a metal-dielectric interface interacts with the a dlayer and spatially localizes or self-traps on the femtosecond time scale into what is termed a small polaron. The dynamics can be studied by two-pho ton photoemission. Theoretical and experimental analyses reveal the interac tion energy and the lattice vibrational mode that mediates electron localiz ation. These results contribute to a fundamental understanding of electron behavior in weakly bonded solids and can lead to a better understanding of carrier dynamics in many different systems, including organic light-emittin g diodes.