Photon-stimulated desorption of methanol on Si(111)7 x 7 and Si(100)2 x 1 at the C 1s and O 1s thresholds

Photostimulated desorption experiments have been performed on deuterated methanol adsorbed on Si(111) 7 x 7 and Si(100) 2 x 1 at the C Is and O Is thresholds. D+ and the masses of the series CDx+ are produced in the photofragmentation process in both energy ranges. A comparison has been made with the photofragmentation spectra of methanol in the gas phase and two different desorption mechanisms have been hypothesized for the desorption of D+ and higher masses from the silicon surfaces at the C Is threshold. (C) 1997 Elsevier Science B.V.