Direct and indirect DIET and DIMET from semiconductor and metal surfaces: What can we learn from ‘toy models ’?
Abstract
Desorption
induced by electronic transitions (DIET) and its variant DIMET (M = ‘Multiple’),
are among the simplest possible “reactions
” of ad-species involving ultra-short lived electronically
excited states at surfaces. The non-adiabatic bond-cleavage can be enforced, for
example, with laser irradiation or with electrons or holes emitted from the tip of a
scanning tunnelling . Lett., 1999, 82, 1967], is studied and compared to so-far hypothetical femtosecond laser desorption. The possibility of controlling the reaction by shaping the laser pulses is addressed. (2)
For the same system, temperature effects are studied for electron- or hole-stimulated desorption with an STM [T. C. Shen, C. Wang, G. C. Abeln, T. R. Tucker, J. W. Lyding, Ph. Avouris and R. E. Walkup, Science, 1995, 268, 1590; C. Thirstrup, M. Sakurai, T. Nakayama and K. Stokbro, Surf. Sci., 1999, 424, L329]. A modified version of Gadzuk’s “
sudden transition and averaging” approach is adopted which accounts for temperature dependent excited state lifetimes. (3) For photodesorption of NO from Pt(111), based on
quantum dynamical simulations possible experimental tests involving static electric fields
are suggested to address the relevance of the recently challenged [F. M. Zimmermann, Surf. Sci., 1997. 390, 174],
“negative
ion resonance” model of the
Antoniewicz type.