Surface morphology on a nanometer scale studied by two-photon photoelectron spectroscopy

The energies of electronic states depend strongly on the size and dimension of the physical system. The high-resolution two-photon photoelectron spectroscopy of weakly-bound image- potential states can be used to monitor the surface morphology of ultrathin metal films. States on terraces of different layer height can be distinguished and the growth mode can be inferred from the presence or absence of several of these states. Lateral localization of the states on small islands leads to an increase of the energy which can be described by the simple model of an electron in a potential well. Distribution of island sizes can be derived on the nanometer scale and compare well with the results of nucleation theory. The high-resolution spectroscopy of image-potential states provides a new tool to study the growth of metal films without disturbing the surface.

[1]  Riess,et al.  Two-photon photoemission via image-potential states. , 1985, Physical review letters.

[2]  P. Halevi,et al.  TWO-PHOTON PHOTOEMISSION SPECTROSCOPY OF IMAGE STATES , 1995 .

[3]  T. Fauster,et al.  Bichromatic two-photon photoemission spectroscopy of image potential states on Ag(100) , 1990 .

[4]  J. Pendry,et al.  The existence and detection of Rydberg states at surfaces , 1978 .

[5]  R. Fischer,et al.  Alloying of thin Ag and Au films on Pd(111) studied by high-resolution photoelectron spectroscopy of surface states , 1996 .

[6]  Fischer,et al.  Three-dimensional localization of electrons on Ag islands. , 1993, Physical review. B, Condensed matter.

[7]  Fischer,et al.  Image states and local work function for Ag/Pd(111). , 1993, Physical review letters.

[8]  G. Rangelov,et al.  Growth and structure of Ag on Pd(111) studied by photoelectron forward scattering using a two-dimensional display-type analyzer. , 1993, Physical review. B, Condensed matter.

[9]  Smith,et al.  Phase analysis of image states and surface states associated with nearly-free-electron band gaps. , 1985, Physical review. B, Condensed matter.

[10]  W. Steinmann.  Two‐Photon Photoemission Spectroscopy of Electronic States at Metal Surfaces , 1995 .

[11]  C. Ratsch,et al.  Saturation and scaling of epitaxial island densities. , 1994, Physical review letters.

[12]  Willis,et al.  Quantum-well states and magnetic coupling between ferromagnets through a noble-metal layer. , 1993, Physical review. B, Condensed matter.

[13]  T. Fauster.  Calculation of surface states using a one-dimensional scattering model , 1994 .