We investigate femtosecond-laser induced desorption [desorption induced by multiple electronic transitions (DIMET)] of NO molecules from thin $\text{Pt}\left(111\right)$ films. On the basis of a two-state, open-system density matrix treatment in combination with a two-temperature model, we argue that decreasing the film thickness enhances desorption cross sections by orders of magnitude in comparison to bulk materials. Both the spatial confinement and the laser fluence appear therefore as efficient, nonlinear enhancement factors for nonadiabatic photoreactions of metal surfaces and, possibly, of nanostructered materials in general.

• Received 9 February 2004

DOI:https://doi.org/10.1103/PhysRevB.69.235405