Molecular dynamics simulation of hydrogen-covered reconstructed Si(1 0 0):H-2 × 1 silicon surface: Calculation of vibrational energy relaxation rates of hydrogen stretching modes

摘要: Abstract Molecular dynamics simulation for hydrogen-covered Si(1 0 0):H-2×1 silicon surface was carried out to calculate the vibrational energy relaxation rates of Si–H stretches based on Bloch–Redfield theory. The calculation gave a lifetime 0.35 ns at 300 K, about three times shorter than experimental result 1.2 ns. With reduction force constants first layer reconstructed dimer Si–Si and Si–Si–Si bends by multiplying with 0.9 in this molecular mechanics field, 0.51 ns, closer calculated above. This suggests that frequencies dimers should be lower bulk modes. In addition, it is noted Si–Si–H bending frequency 625 cm −1 640 Si(1 1 1):H-1×1 but (1 0 0) (1 1 1) surface. contrast previous study which higher lifetime. These results indicate couplings between differ significantly from Besides discussion coupling, isotope thermal effects lifetimes are reported discussed as well.