Deep Ultraviolet Plasmonics Using Momentum-Resolved Electron Energy Loss Spectroscopy

  • Author / Creator
    Poursoti, Zohreh
  • Plasmonics deals with the collective excitations of light coupled with free electrons in matter. It has widespread use in the fields of biosensing and nanoscale waveguiding due to the enhancement of the electric fields. My thesis deals with an important frontier in the field of plasmonics by analyzing excitations in the deep ultra-violet (DUV) and extreme ultra-violet (EUV) spectral region.
    Specifically, I have employed a unique experimental method to probe light-matter interaction in the DUV and EUV regimes beyond the spectral range of conventional probes such as ellipsometers.
    One long-term outcome of my work is to propose new sources of light in this regime where we envision future applications such as DUV and EUV lithography. For this purpose, I have employed a unique momentum-resolved electron energy loss spectroscopy (q-EELS) technique to probe photonic modes in thin films at DUV and EUV energy scales. This thesis presents the theory and experimental results related to q-EELS of semiconductor thin films. EELS deals with the measurement of energy loss of relativistic electrons in a transmission electron microscope (TEM). Our technique, q-EELS is an important advancement that measures not only the energy loss but also the momentum loss of electrons thus giving insight on phenomena such as Cherenkov radiation. For the first time, we show the existence of DUV plasmons in Germanium, opening the possibility of using semiconductor materials as new plasmonic light sources. In addition, we analyze excitations in the extreme-ultra-violet regime in silicon and the temperature dependent characteristics of these high energy plasmonic excitations.

  • Subjects / Keywords
  • Graduation date
    Fall 2023
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.