Abstract. The energy distribution of electrons injected into acceptor states on the surface of TiO 2 was measured with femtosecond two-photon photoemission. Shape and relative energetic position of these distribution curves with respect to the corresponding donor states, i.e. of perylene chromophores in the first excited singlet state attached via different bridge-anchor groups to the TiO 2 surface, were compared with the predictions of different theoretical models for light-induced ultrafast heterogeneous electron transfer (HET). Gerischer's early scenario for light-induced HET was considered and two recent explicit calculations, i.e. a fully quantum mechanical analytical model and a time-dependent density functional theory model based on molecular dynamics simulations for the vibrational modes were also considered. Based on the known vibrational structure in the photoionization spectrum of perylene in the gas phase and that measured in the linear absorption spectra of the perylene chromophores anchored on the TiO 2 surface the energy distribution curves for the injected electrons were fitted assuming the excitation of the dominant 0⋅17 eV vibrational mode in the ionized perylene chromophore leading to a corresponding Franck-Condon dictated progression in the energy distribution curves. Each individual peak was fitted with a Voigt profile where the Lorentzian contribution was taken from the time-resolved HET data and the Gaussian contribution attributed to inhomogeneous broadening. The measured room temperature energy distribution curves for the injected electrons are explained with the fully quantum mechanical model for light-induced HET with the high energy, 0⋅17 eV, skeletal stretching mode excited in the ionized perylene chromophore. The corresponding energy distribution of the injected electrons is fully accommodated in acceptor states on the TiO 2 surface fulfilling the wide band limit.

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The partial pressures of TBP and TMIn were 3.2ϫ 10 −1 mbar and 1.6ϫ 10 −2 mbar, respectively, and not 3.2 mbar and 1.6 mbar as stated in the text of our paper.

The formation of hydrogen bonds was investigated on the P-rich InP͑001͒ surface employing attenuated total-reflection Fourier-transform infrared spectroscopy, low-energy electron diffraction, and total-energy density-functional theory calculations. Strong evidence was found for a c͑2 ϫ 2͒-2P-3H reconstruction with a higher hydrogen coverage than is characteristic for the metal-organic chemical-vapor deposition prepared hydrogen-stabilized ͑2 ϫ 2͒-2D-2H surface. The new surface reconstruction was formed upon exposure to atomic hydrogen. Complete transformation of all the metastable atomic configurations to form the new surface reconstruction was not achieved, since prior to this the surface began to deteriorate. The latter effect was monitored as the formation of In-H bonds. Two observations, i.e., nearly complete screening of the infrared peaks for excitation with p-polarized light and a pronounced redshift of P-H peaks with increasing hydrogen coverage were attributed to dipole-dipole interaction between the vibrating adsorbates.

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