Thermionic emission in gold nanoparticles under femtosecond laser irradiation observed with photoemission electron microscopy

Thermionic electron emission microscopy of metal-oxide multilayers on tungsten

Introduction Thermionic cathodes are used in many industrial vacuum electronic applications. Vacuum tubes for high-frequency or high-power applications are one example (e.g., see [1]). The emission properties of thermionic electron sources in vacuum devices are often Bimproved[ by the addition of oxide coatings on the metal cathode surface [2, 3]. The explanation of the improvement is usually b...

Polyatomic molecules under intense femtosecond laser irradiation.

Interaction of intense laser pulses with atoms and molecules is at the forefront of atomic, molecular, and optical physics. It is the gateway to powerful new tools that include above threshold ionization, high harmonic generation, electron diffraction, molecular tomography, and attosecond pulse generation. Intense laser pulses are ideal for probing and manipulating chemical bonding. Though the ...

Energy dependence of electron lifetime in graphite observed with femtosecond photoemission spectroscopy.

The energy dependence of the electron lifetime in graphite was measured using femtosecond timeresolved photoemission spectroscopy. The lifetime was found to be inversely proportional to the excitation energy above the Fermi level, i.e., sE 2 EFd, in sharp contrast to that of metals, whose lifetime is found to be proportional to sE 2 EFd. The results are in agreement with the prediction of the l...

Femtosecond Thermionic Emission in the Space-Charge Limited Regime

Ultrafast electron transport in layered semiconductors studied with femtosecond-laser photoemission

Femtosecond-laser photoemission was used to investigate the electron dynamics in the layered semiconductors MoSe2 and WSe2. Photoexcitation with 200-fs pulses of 2.03 eV light creates an electron gas with significant excess energy. Our measurements reveal a strong transient enhancement in the diffusive transport of the most energetic electrons relative to the conduction-band minimum. Additional...