Promotionsvortrag Physik: „Investigation of defects in Silicon Carbide and a Tool for FAIR Data Acquisition“

Ankündigung des Promotionsvortrags von: Herrn Johannes Lehmeyer

Color centers in semiconductors are luminescent point defects. They are promising candidates for

applications in quantum technology like quantum communication or nanoscale sensors. Each defect

has its own advantages and disadvantages, thus studying a wide range of different defects is

of interest.

In this talk I focus on the less studied “Temperature Stable” (TS) defect in 4H-Silicon Carbide. This

color center remains as virtually the only luminescent defect after high temperature annealing,

thus making it a promising candidate for applications in which an otherwise unperturbed crystalline

environment is needed.

I present three experiments to investigate the properties of the TS defect and come closer to

identifying its microscopic origin:

The TS defect’s behavior with a changing Fermi Level in the semiconductor reveals information

about other charge states within the bandgap.

The influence of mechanical strain on the TS defect’s photoluminescence (PL) is examined quantitatively.

Under strain, the TS defect’s PL lines split into several lines with distinct polarization,

which is further studied to obtain the spatial direction of the transition dipole moment.

Finally, I present measurements on single defects, which offer further insight into the microscopic

nature of the TS defect.

The talk will close with a brief introduction to a second topic: The development of the open-source

measurement software NOMAD CAMELS. It provides a user-friendly opportunity to directly record

FAIR (“Findable, Accessible, Interoperable, Reusable”) experimental data. Such data is ready for

data-driven and AI-driven science.

(Vortrag auf Deutsch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.