Hot luminescence spectroscopy of non-radiative recombination in silicon

• Applicant: Dr. Friedemann Heinz
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 426644073

The electronic properties of indirect semiconductors such as silicon, which are important for technological applications, are significantly influenced by the non-radiative recombination of excited charge carriers, e. g. via defect levels in the band gap. Details about the physical mechanism of non-radiative recombination, which mainly takes place via Auger processes, have not yet been fully investigated. For the first time, experimental equipment is available today, which enables direct investigation of hot luminescence of Auger carriers in silicon produced by Auger and defect-Auger recombination on short time scales and thus to cover a large parameter space with statistical relevance. The aim of the proposed project is to investigate the fine structure of the hot luminescence and to fill gaps in the physical understanding of the recombination and relaxation mechanisms. In particular, the role of excitonic effects will be investigated. The project lays the basis for a new method of spectroscopy of defect levels within the band gap with an unprecedented low detection limit, which has the potential to complement or even replace existing standard analysis methods of semiconductor research. For the first time, the determination of the properties of defects that are very important for semiconductor research, such as the defect level of the boron-oxygen complex, is thus within reach.

• DFG Programme: Research Grants