scispace - formally typeset
Search or ask a question
Topic

Photoemission spectroscopy

About: Photoemission spectroscopy is a research topic. Over the lifetime, 10821 publications have been published within this topic receiving 250888 citations. The topic is also known as: photoelectron spectroscopy & PES.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the energy dependence of the electron lifetime in graphite was measured using femtosecond time-resolved photoemission spectroscopy, and the lifetime was found to be inversely proportional to the excitation energy above the Fermi level.
Abstract: The energy dependence of the electron lifetime in graphite was measured using femtosecond time-resolved photoemission spectroscopy The lifetime was found to be inversely proportional to the excitation energy above the Fermi level, ie, $({E\ensuremath{-}E}_{F}{)}^{\ensuremath{-}1}$, in sharp contrast to that of metals, whose lifetime is found to be proportional to $({E\ensuremath{-}E}_{F}{)}^{\ensuremath{-}2}$ The results are in agreement with the prediction of the layered electron gas theory, which suggests that electron-plasmon interactions dominate the lifetime of electrons in a layered electron gas, even for small excitation energies, due to interlayer plasmon coupling

95 citations

Journal ArticleDOI
TL;DR: In this article, high-resolution photoemission spectroscopy of newly-discovered iron-based layered superconductor La(O$0.93}$F$_{0.07}$)FeAs (Tc = 24 K) was performed.
Abstract: We report high-resolution photoemission spectroscopy of newly-discovered iron-based layered superconductor La(O$_{0.93}$F$_{0.07}$)FeAs (Tc = 24 K). We found that the superconducting gap shows a marked deviation from the isotropic s-wave symmetry. The estimated gap size at 5 K is 3.6 meV in the s- or axial p-wave case, while it is 4.1 meV in the polar p- or d-wave case. We also found a pseudogap of 15-20 meV above Tc, which is gradually filled-in with increasing temperature and closes at temperature far above Tc similarly to copper-oxide high-temperature superconductors.

95 citations

Journal ArticleDOI
TL;DR: In this article, a soft X-ray photoemission Spectroscopy using surface sensitive Synchrotron Radiation has been applied to accurately determine the binding energy shifts and the valence band offset of the HfO2 grown on Hf metal.
Abstract: Soft X-Ray Photoemission Spectroscopy using surface sensitive Synchrotron Radiation has been applied to accurately determine the binding energy shifts and the valence band offset of the HfO2 grown on Hf metal. Charging of oxide films under x-rays (or other irradiation) is circumvented by controlled and sequential in-situ oxidation. Photoemission results show the presence of metallic Hf (from the substrate) with the 4f7/2 binding energy of 14.22 eV, fully oxidized Hf (from HfO2) with the 4f7/2 binding energy of 18.16 eV, and at least one clear suboxide peak. The position of the valence band of HfO2 with respect to the Hf(m) Fermi level is determined as 4.05 eV.

95 citations

Journal ArticleDOI
TL;DR: An experimental setup for time- and angle-resolved photoemission spectroscopy using a femtosecond 1 kHz high harmonic light source and a two-dimensional electron analyzer for parallel energy and momentum detection is presented.
Abstract: An experimental setup for time- and angle-resolved photoemission spectroscopy using a femtosecond 1 kHz high harmonic light source and a two-dimensional electron analyzer for parallel energy and momentum detection is presented. A selection of the 27th harmonic (41.85 eV) from the harmonic spectrum of the light source is achieved with a multilayer MoSi double mirror monochromator. The extinction efficiency of the monochromator in selecting this harmonic is shown to be better than 7:1, while the transmitted bandwidth of the selected harmonic is capable of supporting temporal pulse widths as short as 3 fs. The recorded E(k) photoelectron spectrum from a Cu(111) surface demonstrates an angular resolution of better than 0.6 degrees (=0.03 A(-1) at E(kin,e)=36 eV). Used in a pump-probe configuration, the described experimental setup represents a powerful experimental tool for studying the femtosecond dynamics of ultrafast surface processes in real time.

94 citations

Journal ArticleDOI
TL;DR: XPS is used to study the densities of states of the metals Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au, and also the compounds ZnS, CdCl2, and HgO and seems to be capable of giving a very good description of the general shape of the density-of-states function.
Abstract: In x-ray photoelectron spectroscopy (XPS), a sample is exposed to low energy x rays (approximately 1 keV), and the resultant photoelectrons are analyzed with high precision for kinetic energy. After correction for inelastic scattering, the measured photoelectron spectrum should reflect the valence band density of states, as well as the binding energies of several core electronic levels. All features in this spectrum will be modulated by appropriate photoelectric cross sections, and there are several types of final-state effects which could complicate the interpretation further. In comparison with ultraviolet photoelectron spectroscopy (UPS), XPS has the following advantages: (1) the effects of inelastic scattering are less pronounced and can be corrected for by using a core reference level, (2) core levels can also be used to monitor the chemical state of the sample, (3) the free electron states in the photoemission process do not introduce significant distortion of the photoelectron spectrum, and (4) the surface condition of the sample does not appear to be as critical as in UPS. XPS seems to be capable of giving a very good description of the general shape of the density-of-states function. A decided advantage of UPS at the present time, however, is approximately a fourfold higher resolution. We have used XPS to study the densities of states of the metals Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au, and also the compounds ZnS, CdCl2, and HgO. The d bands of these solids are observed to have systematic behavior with changes in atomic number, and to agree qualitatively with the results of theory and other experiments. A rigid band model is found to work reasonably well for Ir, Pt and Au. The d bands of Ag, Ir, Pt, Au and HgO are found to have a similar two-component shape.

94 citations


Network Information
Related Topics (5)
Band gap
86.8K papers, 2.2M citations
92% related
Thin film
275.5K papers, 4.5M citations
90% related
Raman spectroscopy
122.6K papers, 2.8M citations
89% related
Amorphous solid
117K papers, 2.2M citations
88% related
Silicon
196K papers, 3M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023128
2022262
2021227
2020281
2019247
2018263