# B. Reihl's research while affiliated with Technische Universität Dortmund and other places

## Publications (181)

Article
Highly-degenerate As-doped n-type and B-doped p-type Si(l11)−(1×1) surfaces have been prepared via ion implantation and laser annealing and studied using photoemission. For As concentrations of ∼4–7%, surface states become very different from those for intrinsic Si(l11)−(1×1) and the Fermi level EF at the surface moves to the conduction band minima...
Article
k-resolved inverse-photoemission spectroscopy is used to measure the energy dispersion E(k||) of the unoccupied electronic surface-state bands of Si(111)2 × 1, Si(111)1 × 1-Ge, GaP(110), and GaAs(110). Comparison with optical transitions between occupied and empty surface states is made by measuring the bulk valence-band states in-situ with ultravi...
Article
Full-text available
We have built an ellipsoidal display analyzer (EDA) for angle-resolved photoelectron spectroscopy and related techniques. The instrument is an improved version of a design by Eastman et al. [Nucl. Instrum. Methods 172, 327 (1980)] and measures the angle-resolved intensity distribution of photoelectrons at fixed energy I(θ,φ)∣E = const.. Such two-di...
Article
The Shockley-type surface state for the clean and a Xe covered Ag(1 1 1) surface is studied with scanning tunneling microscopy and scanning tunneling spectroscopy at a temperature of 5 K. The minimum of the parabolic dispersion shifts from −67 meV below EF=0 for the clean Ag(1 1 1) surface to +52 meV with one layer of Xe adsorbed, hence the surface...
Article
Photoemission energy distribution curves obtained from single crystals of UTe, UTe0.12Sb0.88 and USb in the photo energy range hv<11 eV are interpreted in terms of the densitites of states of the 6d and 5p bands. The fact that the 5f electrons do not contribute to the photoemission spectra is established by observing negative electron spin polarisa...
Article
We have studied silver clusters grown in nanopits on a graphite surface using low-temperature scanning tunneling spectroscopy (STS) at T=5K. The pronounced peak structure measured in the STS data of the clusters is interpreted to have its origin in the quantized electronic structure of the cluster–surface system. Additionally, a systematic spatial...
Article
We have investigated the system Xe on graphite in the submonolayer coverage regime using scanning tunneling microscopy (STM) at T=5 K. The Xe adlayer forms hexagonal domains in a honeycomblike superstructure. Dynamic properties of the domain-walls could be studied for the first time by a series of STM images, revealing a time-dependent overlayer st...
Article
Nanotubes have to be grown in ultrahigh vacuum (UHV) in order to use sensitive surface science methods for their characterization. A carbon deposition on iron and cobalt clusters, which we produced with our method of controlled cluster growth in nanometer sized pits on a graphite surface^1, resulted in the catalytic growth of single-walled carbon n...
Article
Full-text available
We provide a detailed experimental investigation of the electronic band structure of the 3C-SiC(001)-c(4×2) surface using angle-resolved photoemission and synchrotron radiation. A prominent surface state was identified at -1.5 eV and referred to the Fermi level, showing a downwards dispersion by about 0.2 eV. Two other surface states were found at...
Article
We have investigated the 3×3 reconstruction of the 6H–SiC(0001) surface with angle-resolved direct and inverse photoemission (ARUPS and IPES). The surface was prepared by heating the sample in a Si flux and showed an excellent 3×3 LEED pattern. In the ARUPS spectra, three occupied surface states were found at the energies 0.5 eV, 1.5 eV and 1.9 eV...
Article
We studied the electronic structure of quasi size-selected silver clusters grown in nanopits of a graphite surface using ultraviolet photoelectron spectroscopy at T=40K. For clusters with more than 910 2 atoms the initial state of the d-electrons has already reached the bulk limit, but there is a dynamic final-state effect which we can explain with...
Article
Full-text available
We have investigated the electronic structure of the single-domain 3C-SiC(001)(2×1) using angle-resolved photoemission and synchrotron radiation. Two different surface-state bands are clearly identified within the bulk bandgap. The upper band has a binding energy of 1.4 eV at the center of the surface Brillouin zone (SBZ) and shows a weak dispersio...
Article
We have investigated the electronic structure of the single-domain 3C–SiC(001)2×1 using angle-resolved photoemission and synchrotron radiation. Two different surface-state bands are clearly identified within the bulk bandgap. The upper band has a binding energy of 1.4 eV at the center of the surface Brillouin zone and shows a weak dispersion of 0.3...
Article
We have studied the structure of Xe adsorbed on a highly oriented pyrolytic graphite surface in the submonolayer regime using scanning tunneling microscopy (STM) at T = 5 K. The Xe adlayer forms hexagonal domains in a honeycomblike superstructure. We observe domain walls tilted by roughly 12° with respect to the atomic rows of the Xe layer, which e...
Conference Paper
Full-text available
In den hier vorgestellten Experimenten wurden die (√3x√3)R30∘- und die 3x3-Oberflächen mit direkter und auch inverser winkelaufgelöster Photoemissionspektroskopie (ARUPS und IPES) untersucht. Beide Rekonstruktionen werden durch Heizen im Si-Fluß präpariert und mittels LEED und AES eindeutig identifiziert. Die (√3x√3)R30∘-Spektren zeigen einen unbes...
Article
We have measured ultraviolet photoemission spectra of quasi-size-selected silver clusters at T = 40 K grown in the nanopits of a graphite surface. The Fermi-level onset observed shows distinct deviations from the steplike shape typical for metals. A simple model that takes into account the finite lifetime of the photohole (corresponding to a charge...
Article
We have studied the development of the surface electronic structure of a rubidium-adsorbed Si(100)2×1 surface for increasing Rb coverages, with angle-resolved direct and inverse photoemission (IPES). At very low coverages, up to 0.2 ML, the 5s electrons of the Rb atoms fill the minimum of the normally empty substrate-derived surface band. For highe...
Article
A new dedicated UHV STM for investigations at T less than or equal to 5 K is presented. To achieve such low temperatures and to ensure a high thermal stability, the low-temperature (LT) STM described here has a concentric system of bath cryostats. There are openings for tip and sample exchange at low T, and windows with an infrared radiation shield...
Article
A novel low-temperature (LT) surface-science facility based on a two-chamber UHV system has been developed for combined investigations of the electronic and geometric structure of surfaces, employing scanning tunneling microscopy atT≤ 5 K and high-resolution (ΔE ≌ 10 meV) photoemission atT≤ 50 K. A LHe-cooled sample manipulator enables cold transfe...
Article
Gold clusters were produced by condensing evaporated gold in nanometer-sized preformed pits on the surface of highly oriented pyrolytic graphite (HOPG). The height of the clusters was 6.7 Â± 0.7 nm as measured with scanning tunneling microscopy in ultrahigh vacuum, the lateral width was 10.1 Â± 1.9 nm as determined with transmission electron micros...
Article
Full-text available
We have performed scanning tunneling microscopy (STM) in ultrahigh vacuum and transmission electron microscopy (TEM) on silver and gold clusters grown in preformed nanometer-sized pits on the surface of highly oriented pyrolytic graphite. We describe the preparation method and evaluate the three-dimensional shape of the clusters using a combination...
Article
C60 chemisorbs and forms ordered overlayers on both Ag(110) and Au(110)2 × 1: Ag(110)c(4 × 4)C60 and Au(110)(6 × 5)C60. We use direct (UPS) and inverse photoemission spectroscopy (IPS) to examine the occupied and unoccupied electronic structure of Ag(110)c(4 × 4)C60 and IPS to examine the unoccupied electronic structure of Au(110)(6 × 5)C60. Compar...
Article
We have studied the clean Si(100)2 × 1 surface with angle-resolved direct and inverse photoemission spectroscopy (ARUPS and KRIPES) as a function of temperature in the range 300 < T < 1215 K. We note four effects: (i) The dangling bond surface-state emission observed in ARUPS around −0.8 eV below the Fermi level (EF) in normal emission gradually lo...
Article
A low-temperature ultrahigh-vacuum scanning tunneling microscope (STM) is used to excite photon emission from Au(110) surfaces. In the detected photon intensity the ( 1×2) reconstruction of the Au surface is clearly resolved. This first observation of atomic resolution in STM-induced photon emission is interpreted in terms of local variations of th...
Article
Full-text available
Direct and inverse ultraviolet photoemission spectroscopy (UPS and IPS) are used to measure the occupied and unoccupied electronic structure of TiO2(100)1x1 and TiO2(100)c(2x2)K. UPS results from stoichiometric TiO2(100)1x1 are in good agreement with earlier studies. IPS data recorded from TiO2(100)1x1 show two distinct features with energy positio...
Article
We report momentum-resolved inverse-photoemission measurements from a quasi-one-dimensional metal, (TaSe4)2I. Measurements were performed above (300 K) and below (100 K) the Peierls transition temperature (263 K). No change in the spectra is observed that could be associated with the phase transition. The mainly Ta-5d-derived conduction bands displ...
Article
Using a scanning tunneling microscope, the growth of C60 on Ag(110) is explored. The substrate influences the natural tendency of the fullerene molecules to pack closely and an overlayer system with twofold rotational symmetry is formed: Ag(110)c(4×4)C60. This represents a distorted close-packed configuration for the C60 molecules, where the neares...
Article
Applying in situ combination of angle‐resolved photoelectron spectroscopy and k‐resolved inverse photoemission to Si(100):Sb‐1×1 and Si(100):Sb‐2×1 surfaces, we have determined the surface band gaps between the Sb‐derived filled and empty surface states at several points of the surface Brillouin zone. The values of the surface band gaps are compare...
Article
Full-text available
Scanning tunneling microscopy (STM) studies of C 60 molecules on a Au(110) single crystal surface have been performed in ultrahigh vacuum and at low temperatures (5 and 50 K). Submonolayer, monolayer, and bilayer coverages of C 60 have been sublimated onto reconstructed Au(110) 1×2 surfaces. STM images reveal ordered C 60 overlayers which are comme...
Article
We have used a scanning tunneling microscope (STM) as a local electron source to excite photon emission from ordered monolayers of C60 molecules on Au (110) surfaces. In maps of the STM stimulated photon emission the C60 molecules have been spatially resolved. The photon emission is most intense when the tip is centered above a molecule. The diamet...
Article
The novel technique of low-temperature scanning tunneling microscopy is used to study conventional and high-Tc superconductors (spatial identification and distribution of the superconducting gap, vortex movement, etc.), but also custom-designed materials which are unstable at room temperature, e.g. xenon layers and size-selected clusters, or specie...
Article
We have employed scanning tunneling microscopy at room and low temperature, i.e. 300, 50, and 5 K, to study the epitaxy and growth of fullerene films on the noble-metal surfaces Ag(110) and Au(110). Initial island growth occurs on terrace sites away from substrate step edges. Particularly at low temperatures where the rotational and vibrational mov...
Article
We present the first experimental demonstration of spatially resolved photon emission of individual molecules on a surface. A scanning tunneling microscope (STM) was used as a local electron source to excite photon emission from hexagonal arrays of C60 molecules on Au(110) surfaces. Specifically, we show that in maps of photon emission intensities,...
Article
Full-text available
The tip-surface region of a scanning tunneling microscope (STM) emits light when the energy of the tunneling electrons is sufficient to excite luminescent processes. These processes provide access to dynamic aspects of the local electronic structure that are not directly amenable to conventional STM experiments. From monolayer films of carbon-60 fu...
Article
We have studied the formation of monolayer films of lithium, sodium, potassium and cesium atoms on Cu(111) at room temperature with angle-resolved inverse and direct photoemission, and monitored the coverage-dependent changes of the empty and occupied electronic density of states of the alkali adsorbates. All alkali metals formed 2 × 2 overlayer st...
Article
We have studied the electronic structures of lithium, sodium and potassium-adsorbed Si(100)2 × 1 surfaces with angle-resolved direct and inverse photoemission. An empty, overlayer-derived state appeared for all three adsorbates at submonolayer coverage and shifted downwards in energy for increasing coverage. It is assigned to alkali-metal npz or mi...
Article
The surface electronic band structure of the Na-saturated Si(100)2×1 surface has been studied with angle-resolved inverse and direct photoemission. Single-domain 2×1-reconstructed surfaces were obtained by using vicinal samples. At a sodium coverage of roughly half the saturation coverage, an overlayer-derived empty surface state appears at the Gam...
Article
Full-text available
We have performed Scanning Tunneling Microscopy (STM) in ultra-high vacuum at low temperatures (5 and 50K) of unordered and ordered C60 layers adsorbed on a Au(110) surface. STM topographs of the frozen C60 molecules reveal four symmetric patterns within single molecules, which may be associated with different orientations of the fullerenes on a hi...
Article
Alkali-metal layers on semiconductor surfaces are model systems for metal-semiconductor contacts, Schottky barriers, and metallization processes. The strong decrease of the work function as a function of alkali-metal coverage is also technically made use of. Recently, however, interest in these systems is growing owing to ongoing controversial disc...
Article
We have employed angle-resolved direct and inverse photoemission spectroscopy to study the electronic structure of oriented monolayers of hexatriacontane CH3(CH2)34CH3 on Cu(111). Using dipole selection rules we conclude that these polyethylene model compounds lie flat on the copper surface. The valence bands determined experimentally are compared...
Article
Sodium deposited on the cleaved Si(111)2\ifmmode\times\else\texttimes\fi{}1 surface induces a 2\ifmmode\times\else\texttimes\fi{}1$\rightarrow${}1\ifmmode\times\else\texttimes\fi{}1 surface structural transition at about 1/2 monolayer coverage. Angle-resolved direct and inverse photoemission reveal the surface to be semiconducting. The measured ene...
Article
We describe a new scanning tunneling microscope designed specifically for use in an ultra-high-vacuum low-temperature environment. The concept is based on an instrument with interchangeable tip, probe, and a remotely manipulated STM head. The instrumental performance and initial images of a Au(110)(1x2) reconstructed surface obtained with atomic re...
Article
The nature of interfaces formed between alkali metals and silicon (111) surfaces have been investigated with photoemission techniques. The Si(111) 7 × 7-Cs surface is found to exhibit an adatom dangling bond derived surface state with >0·4eV downward dispersion. The metallization of this surface upon continued evaporation beyond the saturation of t...
Article
We have investigated sodium deposition on the cleaved Si(111)2 × 1 surface employing k-resolved direct and inverse photoemission, low-energy electron diffraction (LEED) and work-function measurements. We find that Na lifts the 2 × 1 reconstruction yielding a 1 × 1 LEED pattern. This is in contrast to K which leaves the 2 × 1 surface intact, and Cs...
Article
We have studied the unoccupied surface bands of single-domain Si(100)2 × 1 surfaces with angle-resolved inverse photoemission (IPE). Two surface states are present near the Fermi level (EF) with flat energy dispersions at 1.1 and ∼ 0.4 eV above EF along the Γ-J direction, while along the Γ-J‧ direction these state are dispersive with an apparent cr...
Article
We have studied the electronic structure of potassium-covered Si(100)-(2 × 1) surfaces with angle-resolved direct (ultraviolet) and inverse photoemission at room temperature. Single-domain (2 × 1)-reconstructed surfaces were obtained by using vicinal samples. At a K coverage of less than 1/2 monolayer, an empty overlayer-derived state appears at 2....
Article
The bonding character (ionic versus covalent) of alkali metals on semiconductor surfaces is controversial. This concerns the amount of charge transfer and the question where a possible metallization takes place (alkali overlayer or semiconductor substrate). To give an answer we have employed direct and inverse photoemission spectroscopy to Na, K, a...
Article
The electronic structure of potassium-covered single-domain Si(100)2×1 surfaces has been studied with angle-resolved direct (ultraviolet) and inverse photoemission at room temperature. At saturation coverage, the surface is metallic due to the filling of the minimum of a strongly dispersive empty surface state of mainly K 4pz character. Parabolic-l...
Article
We have studied the development of the electronic structure at the early stages of interface formation of Cs on the Si(111)7×7 surface. Low-energy electron diffraction shows that the 7×7 surface symmetry is conserved throughout the sub-saturation-coverage region. The changes in the surface electronic states characteristic of the clean silicon surfa...
Article
We have determined the unoccupied part of the electronic structure of sodium on Cu(111), employing k-resolved inverse photoemission in the isochromat mode. For Na coverages above 0.15 monolayer, an image-potential surface state is observed 2.3 eV above EF. For the completed p(2×2) Na phase at 0.25-monolayer coverage, a pronounced Na 3pz-derived fea...
Article
The unoccupied electronic structure of the InP(110) surface has been investigated with k-resolved inverse photoemission spectroscopy. Two surface states were detected, partly dispersing in the projected bandgap, with energy positions that agree rather well with optical spectroscopy data. The measured band dispersions, however, are in poor agreement...
Article
The first theoretical and experimental analysis of image states at a semiconductor surface is presented: results of angle resolved inverse photoemission and of ab-initio pseudopotential calculation in the non-local density approximation for GaP(1 1 0) are compared showing the presence of a well defined image state with a dispersion in k-space very...
Article
We have studied the room-temperature deposition of potassium on the cleaved Si(111)2×1 surface with direct and inverse photoemission. In contrast to the analogous cesium case as well as the prediction of a total-energy calculation, we find that the 2×1 reconstruction is stable against K adsorption. The measured energy dispersions of the unoccupied...
Article
We have built and tested a spin‐polarized electron source based on photoemission from negative electron affinity GaAs(100). It provides 5–10 μA of longitudinally spin‐polarized electrons in the energy range 5–20 eV. Following the design of Erdman and Zipf, the electron optics are simple and consist of only five elements. Their voltages are all prop...
Article
The growth of evaporated silicon and germanium on Cu(111) has been studied by angle-resolved direct and inverse photoemission. At room temperature both semiconductors form a reacted interface a few angstroms thick. For overlayers of more than 20-Å thickness the surface-sensitive photoemission techniques demonstrate the growth of pure silicon or ger...
Article
Angle-resolved inverse photoemission has for the first time been used to study the surface electronic band structure of a II–VI semiconductor, CdTe. The energy dispersion of an empty electronic surface state on CdTe(110), previously observed in normal emission only, has been mapped gG-X̄ and gG-X̄ ' in the surface Brillouin zone. In the course of t...
Article
Full-text available
We have measured absorbed-current and secondary-electron-emission spectra in normal incidence and emission, respectively, from the (111), (100), and (110) surfaces of silver. The main features below 10 eV electron energy show good agreement with the bulk band structure for wave vectors normal to the surfaces. Structures due to surface-plasmon thres...
Article
The interaction between the metallic Si(111)7×7 surface and evaporated alkali metals, K and Cs, has been studied by angle-integrated ultraviolet photoelectron spectroscopy and angle-resolved inverse photoemission. Changes observed in both the occupied and unoccupied surface electronic states show a transition from metallic to semiconducting surface...
Article
The cleaved silicon surface of a highly n-type doped crystal has been studied with k-resolved inverse-photoemission spectroscopy (KRIPES). The dispersion of the unoccupied electronic surface-state band of a single-domain 2×1 reconstruction was found to be very similar to p-type doped samples. The band minimum at point J¯ occurs at the same energy v...
Article
We have employed ultraviolet photoemission spectroscopy at hν = 21.2 and 40.8 eV and inverse photoemission spectroscopy at hν = 9.5 eV to study Nd2-xCexCuO4-y (x = 0.0, 0.1, 0.15, 0.2). We observe a shift of the Fermi level to higher energies as a function of x. The total shift is 0.3 eV and saturates at x = 0.2. As suggested by existing band-struc...
Article
Full-text available
The electron affinity levels of condensed films of benzene, chlorobenzene, 1.4‐dichlorobenzene, s‐trichlorobenzene, and hexafluorobenzene on Cu(111) have been determined by isochromat inverse photoemission spectroscopy. In addition to the π∗ orbitals of the benzene ring, low‐lying σ∗ orbitals are observed in the chlorine and fluorine‐substituted mo...
Article
The unoccupied electronic structure of potassium on Cu(111) is determined by angle-resolved inverse photoemission. The observed spectral features are assigned to unoccupied 4p and 3d states of potassium. For a complete monolayer an ordered (2×2) overlayer structure is formed. The dispersion of the K-induced states is determined and compared to a re...
Article
Direct observation of interface formation between alkali metals and semiconductors has been achieved by using a combination of ultraviolet photoelectron spectroscopy and inverse photoemission. The electronic structure thus revealed shows major changes, e.g. the appearance of several alkali-induced surface states, and points to the need for continue...
Article
The development of the electronic structure of two interfaces of alkali metals with semiconductors, K/GaAs(110) and Cs/GaAs(110), has been studied experimentally. Changes in the occupied states have been monitored with ultraviolet photoelectron spectroscopy while the unoccupied states have been investigated using angle-resolved inverse photoemissio...
Article
An investigation of the development of the potassium-covered GaAs(110) surface up to a monolayer coverage has been performed. Low-energy electron diffraction shows that a monolayer of K forms an ordered 1×1 structure. Ultraviolet photoelectron spectroscopy reveals the early formation of a filled surface state extending into the fundamental band gap...
Article
The unoccupied surface electronic structure of cleaved Ge(111)2 × 1 surfaces has been investigated with k-resolved inverse photoemission spectroscopy. A prominent empty surface state is detected, which exhibits a large dispersion in good agreement with the antibonding band calculated for the π-bonded chain model. Identical dispersions are obtained...
Article
Contrary to previous knowledge, we have found an ordered &surd;3×&surd;3 R30° surface reconstruction on the cleaved Si(111) surface after room-temperature deposition of one monolayer of Cs. The preparation and characterization of this surface, and the dispersion of the lowest unoccupied surface-state band as measured with angle-resolved inverse pho...
Article
UHV cleaved GaAs(110) surfaces were irradiated by unmonochromatized UV — radiation from gas discharge sources and by X-rays. A band bending up to 0.6 eV was observed after irradiation with He II, Ne II and Mg Kα, whereas no such effect occurred after He I and Ne I irradiation. The band bending increases with time to a saturation level that depends...
Article
We have placed photon detectors near the tip-sample region of a scanning tunneling microscope (STM). The intensity of the outcoming photons at various energies was measured as a function of bias voltage between tip and sample. Local inverse-photoemission spectra are presented for polycrystalline tantalum, Si(111)7 × 7, and polycrystalline silver, a...
Chapter
In this article we are summarizing our experimental bandstructure results on clean and metal-covered semiconductor surfaces, which we obtained employing the technique of inverse-photoepiission spectroscopy (IPES). The paper is organized as follows. Within the introduction chapter we will give a short description of the inverse-photoemission techniq...
Article
Applying angle-resolved inverse photoemission to cleaved GaAs(110), we have measured the energy dispersion of the unoccupied surface-state bands along the Gamma¯-X¯ and Gamma¯-X¯' symmetry directions of the surface Brillouin zone. The bands are almost parallel to the known occupied surface-state bands, which implies that only one optical transition...
Article
We have detected the light emitted from an STM at both ultraviolet (9·5 eV) and optical (1–4 eV) energies. We show that this light contains spectroscopic information on the sample surface comparable to conventional inverse photoelectric spectroscopy, but with nearly atomic spatial resolution. At optical energies we found sufficiently high intensiti...
Article
Angle-resolved inverse photoemission studies of the Si(111) 1×1 Ge surface reveal an unoccupied surface-state band induced by the germanium overlayer. The band exhibits very little energy dispersion along the major symmetry directions of the surface Brillouin zone. The results are explained in terms of a disordered Si(111) 2×1-Ge surface.
Article
Electron energy loss (EEL) spectra of coldly deposited silver films show the same surface plasmons as observed for Ag(111) and room temperature deposited films. No EEL structure corresponds to the strong anomalous optical absorption centeree at 2.4 eV. We conclude that the latter must be caused by excitations within the porous film.
Article
Full-text available
By placing a photon detector near the tip-sample region of a scanning tunneling microscope, we have measured isochromat photon-emission spectra of polycrystalline tantalum and Si(111)77 at photon energies of 9.5 eV. Such spectra contain electronic-structure information comparable to inverse photoemission spectroscopy, but with high lateral/spatial...
Article
With the technique of k-resolved inverse photoemission a pronounced dispersing surface state is observed for the Si(111)7×7 surface, 0.5 eV above the Fermi level. This state bears strong similarities with the empty adatom states observed on Si(111)&surd;3 × &surd;3 -Al, -Ga, and -In surfaces, and originates from the 12 adatoms in the 7×7 surface ce...
Article
We have measured the energy distribution of backscattered electrons originating from a tungsten field emission tip positioned several hundred μm above an oxidized Si wafer. Energy loss spectroscopy (ELS) and Auger electron spectroscopy (AES) are shown to be feasible in this manner. Hence we suggest a simple scanning type of microscope yielding elec...
Article
We have measured angle-resolved inverse-photoemission spectra of GaP(110) along the Γ̄X̄ and Γ̄X̄́ symmetry direction. An unoccupied, surface-state band near the bottom of the conduction band exhibits a downward dispersion along Γ̄X̄ and appears to be quite flat along Γ̄X̄́. Its minimum energy is found at X̄ to be EF+0.9 eV. Combining this value wi...
Article
Employing k-resolved inverse-photoemission spectroscopy, we have measured the dispersion of the unoccupied electronic surface-state band of cleaved single-domain Si(111) 2\ifmmode\times\else\texttimes\fi{}1 along the $\Gamma${}\ifmmode\bar\else\textasciimacron\fi{}\char21{}J\ifmmode\bar\else\textasciimacron\fi{} and $\Gamma${}\ifmmode\bar\else\text...
Article
We show that the measured peak positions of direct- and inverse-photoemission features near the Fermi level are off from their true values by the order of the energy resolution. Sources of ambiguities are the energy and k resolution, asymmetric line shapes, and high backgrounds. Surface-state bands and/or surface emission which cross the Fermi leve...
Article
We have measured ultraviolet and inverse-photoemission spectra of the novel superconductor Sr02La1.8CuO4. Our results compare favorably with recent band-structure calculations for La2CuO4.
Article
We report k‐resolved inverse photoemission results for the unoccupied surface‐state bands of the reconstructed Si(100)‐(2×1) surface with potassium. The experimental results are compared to the surface‐state bands obtained from geometry‐optimized total‐energy calculations. These self‐consistent field calculations suggest an ionic type of bonding of...
Article
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Article
Employing ultraviolet and inverse photoemission spectroscopy to study Sr0.2La1.8CuO4, we have obtained a density-of-states type of picture of the electronic structure of this novel material which becomes superconducting below Tc=40 K. Our results compare favorably with recent band-structure calculations.
Article
The valence-level excitations of the actinide intermetallic compounds ThPt3, UPt5, and UAu3 have been investigated with resonant photoemission techniques, while those of USn3 have been studied with x-ray photoemission. In all compounds, 5f spectral weight is found at the Fermi energy. Comparison of the spectra with calculated densities of states sh...
Article
k-resolved inverse-photoemission spectroscopy has been used to determine the empty surface-state band structures of Si(111)√3 × √3 -Al, -Ga, and -In surfaces. The results are compared with first-principles pseudopotential total-energy and electronic-structure calculations for energy-minimized geometries of the filled- (T4) and the hollow- (H3) site...
Article
Employing inverse photoemission we have remeasured the energy dispersionE(k) of the lowest-lying image state on Ag(100) with improved energy resolution (electrons and photons, E=0.35 eV) andk-resolution (k–1). In a least-square fit with the binding energyE B atk=0 and the effective massm * as parameters we obtainE B =E vac –0.67 eV andm *=1.5 m i...
Article
Si(111)-(7 × 7) surfaces with deposits of noble metals form ordered overlayers after annealing. Coverages in the monolayer range of Ag and Au result in ()−R30° overlayer structures and for Cu a pseudo “(5 × 5)” structure is produced, while at higher coverage of Au a (6 × 6) overlayer structure is formed. We have studied all four overlayer structure...
Article
Pyrazine (C4N2H4) is probably adsorbed with the molecular plane parallel to the Ag(111) surface, because π−π∗ transitions measured by electron energy loss spectroscopy (EELS) are screened. The inverse and direct photoemission spectra are discussed within the framework of dipolar selection rules. A strong affinity level of pyrazine 2.6 eV above the...
Article
Inverse photoemission spectra of xenon layers adsorbed on Au(110) have been recorded. The unoccupied levels of xenon exhibit layer-dependent peak shifts to higher energies. The 6s level of the second xenon layer is shifted by 0.65 eV relative to the monolayer energy, with the 6p level exhibiting a 0.85-eV shift. These shifts are related to the imag...
Article
The $\surd${}3\ifmmode\times\else\texttimes\fi{}$\surd${}3-Au, $\surd${}3\ifmmode\times\else\texttimes\fi{}$\surd${}3-Ag, "5\ifmmode\times\else\texttimes\fi{}5"-Cu, and 6\ifmmode\times\else\texttimes\fi{}6-Au overlayer interfaces on Si(111) are studied with $k$-resolved inverse photoemission. Strong surface-state emission is observed at \AA{}2.0 eV...

## Citations

... Scanning tunneling microscopy (STM) has been proven to be a capable technique to study and manipulate single molecules immobilized on surfaces [1][2][3][4][5][6][7]. In combination with a photon collection setup, its functionality can be extended to detect the light emitted from the junction [8][9][10][11][12][13][14][15][16]. For a molecule to emit light in a STM junction, it needs to be decoupled from the metallic substrate in order to reduce the hybridization of molecular orbitals. ...
... As a result, by combining scanning tunneling microscopes with photon detecting systems one can study the relation between electron-induced photon emission and local surface structure on atomic and mesoscopic size scales. 2 Gimzewski and coworkers reported the first STM-induced photon emission results from metals (i.e. Ag films) 2 and more recently showed variations in emission yield correlated with atomic spacings in the metallic lattice. ...
... In particular, features of the tunneling current-voltage characteristics determined using the method of scanning tunneling spectroscopy (STS) for nanoclusters of noble and transition metals on the surface of semiconductors [53,54] were inter preted as being due to a gap in the spectrum of electron states of nanoclusters and their transition to a nonme tallic state. In Ag and Pt clusters on HOPG, the STS measurements at T ≈ 5 K revealed discrete electron levels [55,56]. To the best of the authors' knowledge, no STS data on the electron structure of transition metal nanoclusters on the HOPG surface were reported in the literature. ...
... Fig. 14 Li has one of the lowest values of electronegativity of 0.98 [8], much lower than both Si and C. This would suggest in a simple pairing between Li adsorbates and unsaturated surface Si and C atoms, that a set of dipoles directed into the surface would form, reducing the potential difference between the SiC and vacuum, as seen in lithiated diamond and silicon [42,44,45]. The EA calculated for the equilibrium structure shown in Fig. 13 is just 0.08 eV (Table 1). ...
... This effect was theoretically predicted in principle by Villain et al. 58 back in the 1980s. Tilted domain walls were obtained experimentally by Grimm et al. 59 , where the authors showed that the rotation of the xenon lattice on the graphite surface at 4 K is explained by the rotation of hexagonal domain walls separating domains with a commensurate structure. ...
... Of the Group I elements, the interaction of potassium and sodium with the Si͑001͒ surface has been fairly well studied both theoretically and experimentally. [4][5][6][7][8][9][10][11][12] Recently, we have performed detailed calculations of the atomic and electronic structure of the Si͑001͒-Li chemisorption system, 13 and compared the results of these calculations with the existing experimental data, [14][15][16][17][18][19][20][21][22][23][24] and earlier theoretical work. 10,25,26 While some experimental work has been published on the interaction of Rb with the Si͑001͒ surface, [29][30][31][32][33] no theoretical investigation of this Si͑001͒-AM chemisorption system has been reported to our knowledge. ...