Anharmonicity and Lifetime of the CH Stretch Mode on Diamond H/C(111)-(1 × 1)

The anharmonicity and lifetime of the CH stretching vibration of the H-terminated diamond H/C(111)-(1 × 1) surface are investigated. It is found that the ν 1→2 transition is 110 cm -1 lower than the ν 0→1 fundamental. Theoretical calculations show good agreement with the experimental observations and predict the existence of a strongly bound two-phonon bound state. A vibrational lifetime of 19 ps and a similar ground-state recovery time are measured.