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 doctoral research explores how light interacts with advanced nanomaterials: carbon nanotubes, perovskites, and two-dimensional semiconductors. These materials are only a few atoms thick, which gives them optical properties very different from ordinary bulk matter.
Understanding how their structure and composition affect light emission, charge transfer, and stability is key to making them useful. This knowledge is important because it helps overcome long-standing challenges in material science and enables future technologies such as brighter and more stable LEDs, ultrasensitive detectors, secure quantum light sources, and flexible low-cost electronics.
What are the key findings or observations of your doctoral research?
My research shows how the properties of nanomaterials can be tuned by modifying their structure, environment, or by combining them into hybrids.
A method was refined to separate carbon nanotubes into metallic and semiconducting types, which is crucial for electronics. It was demonstrated that oxygen atoms can make nanotubes shine more than twice as brightly, opening routes for quantum communication and bioimaging. I also studied 2D semiconductors and their heterostructures, showing how interlayer interactions control light emission and charge transfer. Most recently, the first stable encapsulation of light-emitting perovskite inside nanotubes was achieved.
These findings solve long-standing problems in materials science, improving material performance, increasing nanotube brightness, and enhancing the stability and uniformity of perovskite emission. They are valuable both for fundamental research and for future technologies such as solar cells, LEDs, detectors, neuromorphic devices, and quantum applications.
How can the results of your doctoral research be utilised in practice?
The results of my research can be used to develop new generations of optoelectronic devices. Brighter carbon nanotubes and stable, uniform perovskites open opportunities for efficient light-emitting devices such as LEDs, lasers, and single-photon sources. The knowledge gained on 2D materials and heterostructures supports the design of ultrasensitive detectors and precise charge-transfer devices.
Together, these findings pave the way for practical applications in solar cells, flexible electronics, energy-efficient sensors, and emerging fields such as neuromorphic and quantum technologies.
What are the key research methods and materials used in your doctoral research?
I combined the preparation of novel nanomaterials with advanced optical measurements. My work covered carbon nanotubes, halide perovskites, two-dimensional semiconductors, as well as their hybrid structures. To study how they interact with light, I used Raman, absorption and photoluminescence spectroscopy, time-resolved photoluminescence, ultrafast pump-probe spectroscopy, and terahertz time-domain spectroscopy. For structural characterization, I employed electron microscopy and X-ray techniques.
These methods allowed me to track how excitations are created, transferred, and relaxed in materials on timescales from femtoseconds to nanoseconds. By comparing pristine, modified, and hybrid materials, I revealed how structural changes and nanoscale confinement affect optical properties. This systematic approach links material design with light-matter interactions, opening new opportunities for fundamental research and optoelectronic applications.
The doctoral dissertation of Valentina Eremina, MSc, Probing light-matter interactions in hybrid nanomaterials: carbon nanotubes, perovskites, and 2D heterostructures will be examined at the Faculty of Science, Forestry and Technology, Joensuu campus. The opponent will be Professor Mika Pettersson, Department of Chemistry, University of Jyväskylä, and the custos will be Professor Yuri Svirko University of Eastern Finland. Language of the public defence is English.
For more information, please contact:
Valentina Eremina, [email protected]
