Linear and Nonlinear Optical Properties of Germanium and Dilute Nitride Containing Semiconductors
Springer, Phillip
The description of the interaction between light and matter is the basis of our understanding of the electro-optical properties of semiconductors. It is of special importance for semiconductor laser systems. The gain medium of these systems is described with the help of a microscopic many-body theory. In this work, such a theory is applied to calculate the photoluminescence of dilute nitride containing semiconductors. Theory-experiment comparisons enable the determination of formerly controversially discussed system parameters of this material class, which represents a promising candidate for more efficient lasers. It is shown that the discontinuity of a GaAs/Ga(NAs) interface is type I. Similarly, a microscopic theory can be applied to calculate the absorption of semiconductors. In this work, the coherent absorption of pump-probe experiments in Ge and (GaIn)As quantum wells is modeled. The experimental findings are reproduced if different dephasing mechanisms are assumed for the samples; a consequence of the different nature of the band gap (direct or indirect). Additionally, the terahertz absorption for indirect semiconductors is modeled. For this purpose, the microscopic many-body theory is extended to include systems with mass anisotropy. On the example of Ge and Si, it is shown that as a result of the mass anisotropy, two distinct resonances appear in the terahertz absorption spectrum.
Philipps-Universität Marburg
2016-06-08
https://doi.org/10.17192/z2016.0213
urn:nbn:de:hebis:04-z2016-02136
http://archiv.ub.uni-marburg.de/diss/z2016/0213