Time-Resolved Photoelectron Spectroscopies Using Synchrotron Radiation: Past, Present, and Future

We present a review on a variety of time-resolved photoelectron spectroscopies (PES) using synchrotron radiation, which can reveal dynamical processes in a wide range of time scale from second to sub-femtosecond by taking advantage of time resolution of detectors or light sources or electronic transitions in matter. As a representative example of light source-based time-resolved PES, the newly developed time-resolved PES system at SPring-8 BL07LSU is introduced along with studies of carrier dynamics on a semiconductor surface. In addition, future direction of time-resolved PES furthered by the recent advances of light sources such as x-ray free electron laser will be discussed.