Doctor of Philosophy
Department of Physics
Piao, Gejin, The excitation and fano resonance spectra of some acceptors in silicon and germanium, Doctor of Philosophy thesis, Department of Physics, University of Wollongong, 1992. http://ro.uow.edu.au/theses/1637
Rich and well resolved p3/2 and p1/2 optical absorption spectra have been observed for indium in silicon and p3/2 spectra for singly ionised zinc, Zn-, in germanium, revealing some new transitions and permitting re-examination in detail of the transition energies, level schemes and deformation potential constants. Ratios of about 4.2 and 4.1 for the binding energies of Zn- in germanium to those of group III impurities and neutral zinc in germanium, respectively, were determined. A comparison with theoretical energies was made, showing excellent agreement.
A set of asymmetric and broad excitation features was observed in the spectra of Zn- in germanium; these have a one-to-one correspondence with the p3/2 transitions and are separated from them by the zone centre optical phonon energy of bulk germanium. These new features have been identified as Fano resonances. The Fano resonance of the G line was found to be well defined, while the G line in the p3/2 spectrum is almost undetectable. This is the first observation of Fano resonances associated with bound holes in germanium. A simple and accurate method has been developed to deduce the parameters q, Γ and f of the resonances.
The stress behaviour of the p3/2, p1/2 and Fano series of indium in silicon for Fll, and and of the p3/2 and Fano series of Zn- in germanium for Fll and and have been observed with linearly polarised radiation. The Fano resonances experience splitting under stress in a way similar to their counterparts p3/2 series. Their strengths, however, do not follow those of their p3/2 counterparts. piezo-Fano selection rules have been derived using group theory. A striking phenomenon for Zn- in germanium is the appearance of the some stress components of the Fano resonances for which their parents in the p3/2 series are strictly forbidden. is consistent with the selection rules which show how the rules for the p3/2 series are relaxed for this type of Fano resonance due to the mediation of the phonon.