The PhD defence and trial lecture will be streamed. The chair of the defence will moderate the disputation.
Ex auditorio questions: the chair of the defence will invite the audience physically present in the auditorium to ask ex auditorio questions.
→ Live streaming of trial lecture and disputation
→ Request for thesis copy (available until the disputation starts)
Trial lecture
Time and place: September 10, 2026 - 10:15 AM
Lille Fysiske auditorium (V232) - Fysikkbygningen
Title: "Semiconductor defect engineering in quantum technology"
Main research findings
Hydrogen is both a key ingredient and a potential challenge in modern silicon solar cells. It is essential for achieving today’s high efficiencies. Yet, growing evidence suggests that hydrogen-related processes may contribute to a puzzling degradation phenomenon known as light- and elevated temperature-induced degradation (LeTID), which affects the lifetime of charge carriers and, ultimately, solar cell performance.
This thesis uses Fourier-transform infrared (FTIR) spectroscopy, which enables probing of hydrogen centers in silicon. Combined with carrier lifetime measurements, the work tracks the evolution of hydrogen centers and links these changes to degradation.
The results show that the amount of hydrogen introduced during processing strongly influences degradation, with lower hydrogen concentrations leading to weaker degradation. The study also reveals that different dopants favor different dominant hydrogen species and identifies several previously overlooked hydrogen complexes that contribute to the overall hydrogen balance. In addition, the measured evolution of hydrogen centers over time was quantitatively compared with a model. This provides further insight into the mechanisms behind degradation.
These findings provide new insight into the role of hydrogen in silicon and support the development of silicon solar cells that maintain their performance more reliably over time.
Adjudication Committee
- Professor Hele Savin, Department of Electronics and Nanoengineering, Aalto University, Finland
- Associate Professor Ruy Sebastian Bonilla, Department of Materials, University of Oxford, United Kingdom
- Professor Joakim Bergli, Department of Physics, University of Oslo, Norway
Supervisors
- Professor Eduard Monakhov, Department of Physics, University of Oslo, Norway
- Professor Andrej Kuznetsov, Department of Physics, University of Oslo, Norway
Chair of defence
Professor Andreas Görgen, Department of Physics, University of Oslo, Norway
Contact information to Department: Line Trosterud Resvold