Universität Stuttgart
Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1
Browse
6 results
Search Results
Item Open Access Influence of defects on the splitting of the acceptor ground state in silicon(1984) Ambrosy, Anton; Lassmann, Kurt; Goer, Anne M. de; Salce, Bernard; Zeile, Heinrich-Item Open Access Resonance and relaxation attenuation by neutral acceptors in a magnetic field(1977) Schad, Hanspeter; Lassmann, Kurt; Zeile, HeinrichFine structure, level splitting, and relaxation times of the acceptor ground state in cubic semiconductors can be deduced from ultrasonic attenuation. By the application of a magnetic field it is possible to vary the coupling strength and the number of acceptors on speaking terms with the ultrasonic wave. Making use of this possibility, we have determined directly effective coupling constants for relaxation attenuation and the temperature dependence of the critical intensity for saturation of the resonant interaction. Results obtained for p-type GaAs and Si are discussed in comparison with analogous results for glasses.Item Open Access The distribution of splittings (Ultrasonic investigation of the acceptor ground state of Si(B) ; 2)(1982) Zeile, Heinrich; Lassmann, KurtThe splitting distribution of the acceptor ground state of Si(B) is determined from the frequency dependence of the ultrasonic resonance attenuation and from acoustic paramagnetic resonance. In the purest crystals a residual distribution is found of unknown origin. In crystals containing carbon or oxygen at concentrations above about 10 22 m-3 the distribution is broadened in rough accordance with statistical estimates.Item Open Access The longitudinal and transverse relaxation rates of the strain-split two-level system (Ultrasonic investigation of the acceptor ground state of Si(B) ; 1)(1982) Zeile, Heinrich; Harten, Ulrich; Lassmann, KurtThe spin-lattice relaxation of the two-level system of the strain-split acceptor ground state of Si(B) is determined from the temperature dependence of the ultrasonic relaxation attenuation, around 10 K. It is found that Raman relaxation alone does not fit the results but that, in addition, an Arrhenius-type of relaxation, possibly due to a Jahn-Teller effect, is involved. The transverse relaxation is obtained from intensity-dependent and hole-burning measurements of the resonant attenuation. At small acceptor concentrations it is determined by spin-lattice relaxation alone; for higher concentrations an additional temperature-independent interaction term is found much smaller than expected for elastic dipole or exchange interaction.Item Open Access Ultrasonic spectroscopy of the acceptor ground state in cubic semiconductors(1980) Lassmann, Kurt; Zeile, HeinrichIn the following we will discuss ultrasonic measurements on p-type semiconductors reflecting spontaneous and defect sensitive modifications of the acceptor ground state.Item Open Access Ultrasonic spectroscopy in p-type silicon(1979) Zeile, Heinrich; Mathuni, Otto; Lassmann, KurtFrom ultrasonic resonant absorption over a wide frequency range we have determined the distribution of the energy splittings of the acceptor ground state in very pure Si(B) crystals. The measured distributions with maxima of the order of 10μeV fit well to the expected electric field distribution from the~ 10 12 cm-3 residual donors. The critical intensity for saturating the resonance attenuation has been measured in crystals of various acceptor concentrations and as a function of temperature. Although the average distance of acceptor atoms is much greater than the Bohr-radius of the bound defect-electrons, relaxation times are found to be shortened by the acceptor-acceptor interaction.