Walter Schottky Institute
Center for Nanotechnology and Nanomaterials

Semiconductor Quantum Nanomaterials - Research
Group leader: PD Dr. Gregor Koblmueller (Chair of Prof. Dr. Jonathan Finley)


HOMENEWSPEOPLEPUBLICATIONSRESEARCHTEACHINGOPENINGSFUNDING


Our research activities on semiconductor quantum nanomaterials aim at four different domains. These encompass "Advanced Synthesis" using ultrahigh-purity molecular beam epitaxy methods, "Functional Imaging" to interrogate key structure-property-function relationships, "Integrated Photonics" describing the development of novel on-chip integrated nanolasers and quantum light sources, and "Quantum Electronics" addressing new concepts in nanowire-based quantum transport, in topological semi-/ superconductors, and nano-thermoelectrics research.




ADVANCED SYNTHESIS

[research]
A major workhorse for our research on advanced nano-systems/devices are innovative semiconductor nano- & quantum-heterostructures created by design using accurately controlled synthesis methods. Specifically we employ ultrahigh-purity molecular beam epitaxy (MBE) dedicated to III-V compound semiconductors (arsenides / antimonides), group-III nitrides as well as  new classes of emerging 2D materials. The latter are synthesized in a new MBE-cluster system in collaboration with the MWM sub-group. Currently, a substantial effort in synthesis is on III-V nanowires (NW), which offer unique capabilities in heterostructure and crystal phase engineering, as well as site-selective growth and deterministic incorporation of atomically engineered low-dimensional quantum systems. The following selection of key publications gives a brief view into ongoing activities in growth/synthesis research of 1D-NWs and their quantum heterostructures.


Personnel

M. Bissolo, C. Doganlar, H. Esmaielpour,  G. Hirpessa, H. W. Jeong, S. Meder, P. Schmiedeke, T. Schreitmüller, A. Uhle

Selected publications


H. W. Jeong, et al., “Sb-mediated tuning of growth and exciton dynamics in entirely catalyst-free GaAsSb nanowires”, Small 19, 2207531 (2023). 


F. Del Giudice, et al., “Epitaxial type-I and type-II InAs-AlAsSb core-shell nanowires on silicon”, Appl. Phys. Lett. 119, 193102 (2021).



D. Ruhstorfer, et al., “Growth dynamics and compositional structure in periodic InAsSb nanowire arrays on Si (111) grown by selective area molecular beam epitaxy", Nanotechnology 32, 135604 (2021). 



B. Sun, et al., “Dislocation-induced thermal transport anisotropy in single-crystal group-III nitride films”, Nature Materials 18, 136 (2019).



                                                                                                                                                                                                                                                                                                                                                                                                           



FUNCTIONAL IMAGING

[research]
To establish the as-grown quantum nano-structures for various different devices, it is important to clearly understand their structure-property relationships to predict their performance. This requires advanced high-resolution spectroscopy and imaging methods to resolve properties quantitatively and at the nanoscale. Here, we employ a whole toolbox of different nano-metrology techniques to link specific structural and morphological features with electrical, optical, mechanical and thermal properties. Examples of such methods include electrical scanning probe microscopy (SPM) techniques, high-resolution electron and ion-beam microscopy, µRaman spectroscopy, time- and spatially resolved µPL spectroscopy (vis-to-midIR), absorption spectroscopy, etc. Typical examples of research in this field are illustrated in various selected publications.


Personnel

M. Bissolo, C. Doganlar, H. Esmaielpour, G. Hirpessa, H. W. Jeong, S. Meder, P. Schmiedeke, T. Schreitmüller, A. Uhle


Selected publications