SURFACE-STATES AND SPACE-CHARGE LAYER DYNAMICS ON SI(111)2X1 - A FREE-ELECTRON LASER-SYNCHROTRON RADIATION STUDY

Combining the use of a UV storage ring free electron laser and of sync hrotron radiation, a time resolved core level spectroscopy study has b een performed on photoexcited Si(lll)2x1 surfaces with subnanosecond r esolution. This enabled us to measure band bending fluctuations, cause d by surface carrier dynamics, during the first nanosecond after photo excitation; differences in the Si2p core level lineshape, dependent on the pump-probe time delay, were also observed. The presence of defect s was found to reduce the fluctuations and make the carrier recombinat ion process faster. (C) 1997 American Institute of Physics.