The doctoral dissertation in the field of Physics will be examined at the Faculty of Science, Forestry and Technology, Joensuu campus.
What is the topic of your doctoral research? Why is it important to study the topic?
My research develops waveguide-integrated photodetectors using two-dimensional semiconductor materials on silicon nitride photonic chips. It is important because integrated photonics needs compact, efficient on-chip detectors for sensing, communications, and emerging photonic systems, and 2D materials enable strong absorption in an ultrathin layer that can be added onto existing waveguides.
What are the key findings or observations of your doctoral research?
I demonstrated and characterized 2D-material photodetectors integrated on low-loss silicon nitride waveguides, and linked fabrication and integration choices to device performance and stability. The work provides practical device designs and process steps that enhance light–matter interaction in a small footprint and improve repeatability, which is valuable for scalable on-chip optoelectronics.
How can the results of your doctoral research be utilised in practice?
The results support adding compact photodetectors directly onto photonic chips, reducing external components and enabling integrated modules for optical sensing and communication. The process and design guidelines can be reused to improve scalability, and reliability when integrating 2D materials on photonic platforms.
What are the key research methods and materials used in your doctoral research?
The work combines cleanroom nanofabrication and device testing. Silicon nitride waveguides were fabricated using lithography and plasma etching, contacts were formed using thin-film deposition and patterning, and 2D materials were integrated onto the waveguides. Devices were evaluated with optical coupling and electrical photoresponse measurements, supported by SEM, AFM, and Raman when needed.
Is there something else about your doctoral dissertation you would like to share in the press release?
The dissertation provides both experimental results and practical fabrication know-how for integrating emerging 2D materials with established photonic chip platforms, aimed at enabling scalable device fabrication for future applications.
The doctoral dissertation of Maaz Ahmed Qureshi, MSc, entitled Waveguide-Integrated 2D Material Photodetectors: Fabrication and Characterization will be examined at the Faculty of Science, Forestry and Technology, Joensuu campus. The opponent will be Associate Professor Sanshui Xiao, Technical University of Denmark (DTU), Denmark, and the custos will be Professor Markku Kuittinen, University of Eastern Finland. Language of the public defence is English.
For more information, please contact:
Maaz Ahmed Qureshi, [email protected], tel. +358 50 401 5051
- Public examination
- Dissertation (PDF)
- Photo (coming)
