Seminar - Simple Electron Microscope

Abstract:

The scanning electron microscope produces images with a large depth of field and a natural lighting quality, as though microscopic objects are seen by the naked eye. This makes it an intuitive and broadly applicable instrument, but cost and complexity limit its reach. In this seminar, a compact and low-cost electron microscope [1] is described that is enabled by a photothermionic cathode based on carbon nanotubes [2]. The instrument was built using common components and hobby-level electromechanics, and has a flexible and customizable design. The goal is not only to broaden access to this imaging technique for traditional users, but also to expand it to application domains and scenarios that have not been able to employ it in the past.

[1] Nature Communications 16, 8067 (2025)

[2] MRS Bulletin 42, 500 (2017)

Speaker Bio:

Dr. Alireza Nojeh works on electron emission phenomena and vacuum nanoelectronic devices including free-electron instruments and energy converters. Much of his work has revolved around optical excitation of carbon nanotubes leading to localized heating and the thermal emission of electrons and photons. He studied at Sharif University of Technology (BS, MS), the University of Paris XI-Orsay (DEA), and Stanford University (PhD). He has been at UBC since 2006, where he is a professor in ECE and an investigator at QMI, and a member of AMPEL and ICICS and, of course, Characterization@UBC.