Thermal radiation and fragmentation pathways of photo-excited silicon clusters

• The fragmentation of laser heated silicon clusters was studied by time-of-flight mass spectrometry. For Si+n (n = 5–19, 21), the lowest energy fragmentation pathways were identified as the metastable decay channel occurring after the primary acceleration of the ions. The radiative cooling of laser excited Si+n (n = 5–9, 11, and 13) was quantified via its quenching effect on the amount of metastable fragmentation. The quenching varied strongly with cluster size, from no observable amount for Si+7 to a cooling constant of 3 · 10E5 s−1 for Si+13. In addition, based on the observed fragmentation channels, the ionization energies and the relative binding energies of the clusters were partially ordered, and several ionization energies have been bracketed more precisely.

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Silicon clusters

radiative cooling

mass spectrometry

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)