line decor
   :: W&M Home :: Applied Science :: Optics and Laser
line decor


Defects in Semiconductors 

Important Results:

  1. Bond Center Hydrogen
  2. H/D Isotope Effect
  3. Structure Dependent Lifetimes
  4. Hydrogen Bending Modes
  5. Interstitial Oxygen in Si and Ge


>> Hydrogen Bending Modes

Vibrational lifetimes of hydrogen and deuterium related bending modes in semiconductors are measured by transient bleaching spectroscopy and high-resolution infrared absorption spectroscopy. The vibrational lifetime T1 = 12.2  ± 0.8 ps for the bending mode of H2* in Si.

We find that the vibrational lifetimes follow a universal  frequency-gap law, i.e., the decay time increases exponentially with increasing decay order, with values ranging from 1 ps for a one-phonon process to 265 ps for a four-phonon process. The temperature dependence of the lifetime shows that the bending mode decays by lowest-order multi-phonon process. Our results provide new insights into vibrational decay and the giant isotope effect of hydrogen in semiconductor systems.



  1. B. Sun, G. A. Shi, S. V. S. Nageswara Rao, M. Stavola, N. H. Tolk, S. K. Dixit, L. C. Feldman, G. Lüpke, Vibrational Lifetimes and Frequency-Gap Law of Hydrogen Bending Modes in Semiconductors, Phys. Rev. Lett. 96, 2006, pp. 035501-4.

<< Back :: Structure Dependent Llifetimes ::

>> Next :: Interstitial Oxygen in Si and Ge ::

Funding: NSF, DoE, Jeffress Foundation




line decor
    :: Welcome to the Optics and Laser group home page :: We suggest browser versions:: Firefox 1.5 :: Safari 2.0 :: Last updated :: Dec. 18th. 2015
line decor