Anelastic spectroscopy as a probe for the structure and dynamics of defects in semiconductors

The anelastic spectroscopy is a powerful method for studying the dynamics and geometry of defects and excitations carrying a local distortion. The vibrational stress affects the energy levels of the defects, which approach the dynamically perturbed thermal equilibrium, giving rise to dissipation of energy. The analysis of anelastic spectra provides the values of the defect jumping (or transition) rates and of the associated energy barriers. Furthermore, the application of the stress along different crystallographic directions gives indications on the symmetry of the relaxing defects. In this manner, important information on some hydrogenated complexes in semiconductors has been obtained. We report an overview of the more meaningful results in Si and III-V compound semiconductors.