Séminaire Cethil : Electron and photon emission from locally heated carbon nanotubes, Alireza Nojeh, University of British Columbia

Arrays of vertically-aligned multiwall carbon nanotubes, also known as multiwall carbon nanotube forests, are conductive materials. Yet, when a focused beam of light strikes a nanotube forest, the generated heat remains confined to the illuminated region. This makes it possible to achieve a high-temperature spot on the material using low optical power, for example from an inexpensive laser pointer, and leads to the localized thermal emission of electrons and photons. We will discuss this ‘heat trap’ effect, its characteristics, and example applications that it enables in energy conversion and free-electron devices, notably a compact, inexpensive electron microscope. We will also cover several possible mechanisms behind this heat localization and experimental efforts on its detailed characterization, in particular on thermal electron spectroscopy and thermal photon hyper-spectroscopy.