Vibrational Dynamics of Defects in Semiconductors

The goal of this project is to elucidate the dynamics of local vibrational modes (LVMs) of defects related to light impurities in crystalline semiconductors, including Si, Ge, GaAs, and ZnO. Knowledge of the rates and pathways of vibrational energy flow is critical for understanding thermally and electronically stimulated defect and impurity reactions and migration in semiconductors. Hence a detailed understanding of the energy transfer channels and the coupling mechanism between LVMs and the phonon bath of the host material is needed. The mechanisms for population and phase relaxation upon excitation of those modes, in both frequency and time domain, are investigated.

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

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Funding: NSF, DoE, Jeffress Foundation