Structure-dependent vibrational lifetimes of hydrogen in silicon -: art. no. 135501

The lifetimes of the Si-H vibrational stretch modes of the H-2* ( 2062 cm(-1)) and HV . VH(110) (2072.5 cm(-1)) defects in crystalline Si are measured directly by transient bleaching spectroscopy from 10 K to room temperature. The interstitial-type defect H-2* has a lifetime of 4.2 ps at 10 K, whereas the lifetime of the vacancy-type complex HV . VH(110) is 2 orders of magnitude longer, 295 ps. The temperature dependence of the lifetime of H-2* is governed by TA phonons, while HV . VH(110) is governed by LA phonons. This behavior is attributed to the distinctly different local structure of these defects and the accompanying local vibrational modes.