PhD defence by Anastasiia Vladimirova

Abstract

Today's electronic devices are reaching their limits when it comes to speed, energy efficiency, and how much data they can handle. One promising way to overcome these challenges is combining electronics with light-based technology. Using light to move data around can make devices faster and more energy-efficient. Since most electronics are built using silicon, finding a way to use light within silicon-based systems is important for making this technology widely usable. However, one big hurdle remains: silicon does not naturally produce light efficiently.

This research explores whether it is possible to create a light source using silicon that works in the infrared range, which is useful for data communication. In particular, the study focuses on a process called "hot carrier emission," where
highly energized current carriers in silicon can release light while relaxing its energy. I studied how these carriers behave using advanced stochastic simulations based on quantum mechanics. Then, I looked at how nanostructures,
resonating within the infrared range, can boost the hot-carriers emission by confining the emitted light in very small volumes. Additionally, I designed and tested these nanoscaled light resonators.

Overall, this work helps us better understand the physics behind light generation in silicon, highlighting the challenges and limitations of achieving an efficient silicon-based infrared light source.

Supervisors

• Principal supervisor: Professor Søren Stobbe, DTU Electro, Denmark
• Co-supervisor: Professor Jesper Mørk, DTU Electro, Denmark

Evaluation Board

• Professor Jakob Schiøtz, DTU Physics, Denmark
• Dr. Jelena Sjakste, Ecole Polytechnique, Palaiseau, France
• Professor N. Asger Mortensen, University of Southern Denmark, Denmark

Master of the Ceremony

• Senior researcher Philip T. Kristensen, DTU Electro, Denmark