University thesis:
Dissertation, Albert-Ludwigs-Universität Freiburg im Breisgau, 2018
Footnote:
Description:
Abstract: The silicon-vacancy center (SiV-center) is a promising candidate for quantum-physical applications due to its physical properties. Besides its narrowband photon emission at 738 nm wavelength, it shows a high photo-stability already at ambient conditions. Con- trary to the well-known and extensively studied nitrogen-vacancy center (NV-center), the physical properties of the silicon-vacancy center are not known well enough at the moment for actual applications in the area of quantum-computing or quantum- communication. Especially the possibility of electrical excitation and the luminescence properties of different charge-states of the SiV-center are not sufficiently proven. The present work intends to narrow this gap. Therefore, after initial optimization of the diamond growth-processes in ellipsoidal cavity Microwave Plasma Enhanced Chemical Vapor Deposition (MWPECVD) reactors developed at Fraunhofer IAF, diamond PIN- and Schottky-diodes with in-situ incorporated as well as implanted silicon-vacancy cen- ters, respectively, were fabricated. With these devices, the electrical excitability of the luminescence of silicon-vacancy centers was studied. Additionally, experiments for exploring the luminescence properties of the silicon-vacancy center at different surface terminations (hydrogen-, oxygen-, and fluorine-termination) influencing its charge-state were performed. For a more detailed investigation of the SiV charge states, a two- dimensional Schottky-diode was fabricated from diamond, allowing to control the charge states actively and examine the resulting optical properties of the silicon-vacancy center. An ATLAS-simulation of the luminescence behavior observed in the two-dimensional Schottky-diode was performed to explain the physical processes and the experimental observation. The simulation indicates, that a charge state shift between SiV0 and SiV− (possibly even to SiV2−, which have been predicted theoretically), could be observed in the present experiment. Thereby, it could be shown, that a shift of the charge state of the SiV-centers from neutral to negative charge state could qualitatively explain the lu- minescence behavior observed. The methods as well as the obtained results, embedded in the physical backgrounds are extensively discussed and interpreted in the present thesis