Project B3: THz and Time-Resolved Optical Spectroscopy of Buried Interfaces

Principle Investigator: Prof. Dr. Martin Koch, Prof. Dr. Wolfram Heimbrodt (Marburg, Dept. of Physics)

Summary

The main focus of this project is the experimental study of the carrier dynamics at buried interfaces in semiconductor systems. We will employ optical pump-white-light probe, optical pump-Thz probe spectroscopy and time-resolved luminescence to study the initial charge transfer through the interface as well as the formation and decay dynamics of charge-transfer excitons. As a new aspect we will also investigate the coherent dynamics of charge-transfer excitons performing four-wave-mixing experiments on spatially indirect transitions. In the second phase of the collaborative research center we will intensify our investigations to reveal correlations between the structural quality of the interface and the carrier dynamics on the different time-scales. In addition, we will continue to study how strong transient THz fields modify the initial carrier dynamics at buried interfaces.
The samples will be grown in project A1 (Stolz) and will be structurally characterized in project A5 (Volz). The analysis of the experimental data will be performed in close cooperation with B4 (SW Koch).

Project-Related Publications

1. M. J. Drexler, R. Woscholski, S. Lippert, W. Stolz, A. Rahimi-Iman, M. Koch Disturbing the Coherent Dynamics of an Excitonic Polarisation with strong THz fields Phys. Rev. B 90, 195304 (2014).
2. J. Kuhnert, A. Rahimi-Iman, W. Heimbrodt Magneto-Photoluminescence measurements of tungsten disulphide monolayers J. Phys. Condens. Matter 29 (2017).
3. S. Gies, B. Holz, C. Fuchs, W. Stolz, W. Heimbrodt Recombination dynamics of type-II excitons in (Ga,In)As/GaAs/Ga(As,Sb) heterostructures Nanotechn. 28, 025701 (2017).
4. M. Stein, C. Lammers, P. Springer, P.-H. Richter, S. W. Koch, M. Koch, M. Kira Density-dependent exciton dynamics and L-valley anisotropy in germanium Phys. Rev. B 95, 155207 (2017).