Theory of carrier dynamics in Silicon HotElectron Light Sources

Modern electronic devices face increasing limitations in power consumption, heat dissipation, and bandwidth, restricting their ability to meet growing data processing demands. Nanophotonic integration with electronics offers a promising solution by enabling faster and more energy-efficient data transfer. Since the semiconductor industry relies heavily on silicon, leveraging silicon for nanophotonics ensures compatibility with CMOS fabrication, making it an ideal platform for large-scale integration. However, a major challenge remains: the absence of an efficient on-chip silicon-based light source. In this thesis, I investigate the theoretical feasibility of a silicon-based infrared light source leveraging hot carrier emission. I review the main scattering processes hot carriers are subject to, and calculate their probabilities using density functional theory techniques. These probabilities are then incorporated into stochastic simulations to model hot carrier dynamics in reciprocal space. Then, I explore how Purcell enhancement, achieved through nanophotonic cavities with bowtie-like features that enable extremely small mode volumes, can enhance hot carrier emission. I also design and experimentally characterize cavities that combine high-Q factors, small mode volumes, and the ability to be optically and electrically pumped. This work provides fundamental insights into hot carrier dynamics and cavity-enhanced emission in silicon, highlighting the challenges and limitations of achieving an efficient silicon-based infrared light source for integrated photonic applications.