Universität Stuttgart

Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1

Browse

Filters

1990 - 19935

Settings

Publication Type: search.filters.UBSTyp.KonferenzbeitragSubject: search.filters.subject.530Author: search.filters.author.Lassmann, KurtStart date: 1990End date: 1993

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    Phono-conduction spectroscopy of shallow states in semiconductors
    (1990) Lassmann, Kurt; Gienger, Martin; Groß, Peter
    Phonoconduction spectroscopy of shallow states in semiconductors by help of superconduction Al-junctions as phonon sources with high spectral resolution is a sensitive new technique with phonon frequencies well up in the Debye range. The large k-vector of the phonons involved opens new possibilities for the investigation of electron dynamics and states in semiconductors.
  • Thumbnail Image
    ItemOpen Access
    Investigation of A+-states in Si and Ge by phonon-induced conduction under uniaxial stress
    (1993) Groß, Peter; Lassmann, Kurt
    By the analysis of the stress dependence of phonon induced conductivity (PIC) with superconducting Al-tunneling junctions as phonon generators we have now found strong evidence for a split ground state in the cases Si:Ga+, Si:Al+ and Ge:Zn+.
  • Thumbnail Image
    ItemOpen Access
    Phonon spectroscopy of low energy vibrations of interstitial oxygen in germanium
    (1993) Lassmann, Kurt; Gienger, Martin; Glaser, Markus
    We can summarize our results as follows: Whereas the band of lowest lying mechanical states of interstitial oxygen in Si can be approximated by a two-dimensional oscillator perturbed by a central potential, the corresponding states in Ge can be well understood by a bindered rotator with a large central potential opposing a bending oscillation and with a sixfold modulation of the rotation due to the influence of the 6 neighbours to the Ge-O-Ge molecule
  • Thumbnail Image
    ItemOpen Access
    Depopulation effects in the phonoconduction response of A+ -states in silicon and germanium
    (1990) Groß, Peter; Gienger, Martin; Lassmann, Kurt
    We show here that deviations from these assumptions are effective in the experiment and responsible in particular for the observed illumination dependence of the phonoconduction signal. The phonon spectrum of an Al - STJ at bias V = eU > 2ΔAl consists of a continuum with a sharp threshold at Ώm = V - 2ΔAl. In the differentiated spectrum Ώm becomes the most prominent bias-tunable feature, namely the quasimonochromatic line of phonon spectroscopy used for the approximate analysis of sharp phonon scattering resonances such as the OI line of Fig. 1a (which shows inversion of the center due to strong scattering).
  • Thumbnail Image
    ItemOpen Access
    Resonant phonon scattering by calcium colloids in electron irradiated calcium fluoride
    (1993) Wurster, Clemens; Lassmann, Kurt; Eisenmenger, Wolfgang
    Here we report on such an investigation of Ca-colloids produced by e- -irradiation in CaF2. We find a good correlation of the observed phonon scattering (and its variation with thermal treatment) with a resonance peak in the optical Mie scattering.