VIBRATIONAL-ENERGY RELAXATION DYNAMICS OF SI-H STRETCHING MODES ON STEPPED H SI(111)1X1 SURFACES (VOL 200, PG 357, 1995)/

The vibrational energy relaxation rates of excited Si-H stretching mod es on the monohydride step of miscut H/Si(111)1x1 surfaces are calcula ted using Bloch-Redfield theory combined with classical molecular dyna mics (MD) simulation. The structure and vibrational frequencies of the surface are first investigated using the Car-Parrinello ab initio MD method. The calculated Si-Si-H bending frequencies and relaxed structu res are then used to refine the empirical potential for the classical MD simulations. The lifetime of the excited Si-H stretching mode at th e step is found to be shorter than the modes on the terrace. Both the magnitude and the trend of the calculated results agree well with the experimental measurement on the 9 degrees monohydride stepped surface. The vibrational relaxation rate of the Si-H stretching modes on the 1 5 degrees monohydride stepped surface are also calculated and predicte d to have a slightly shorter lifetime than for the 9 degrees surface.