Photoinduced desorption (PID) of Xe from porous silicon (PSi) following UV irradiation has been studied. A nonthermal, morphology, and wavelength dependent phenomenon with more than 3 orders of magnitude enhancement of Xe PID within pores over atoms adsorbed on top of flat surfaces has been recorded, displaying extraordinary large cross sections up to ${\sigma }_{\mathrm{Xe}/\mathrm{PSi}}=2\times {10}^{-15}{\mathrm{cm}}^2$. A long-lived, photoinduced, charge separated silicon-xenon complex is proposed as the precursor for this remarkable photodesorption process.

• Received 20 April 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.167402