A new ESCA instrument with improved surface sensitivity, fast imaging properties and excellent energy resolution

The use of mixed self‐assembled monolayers, combining hydrophobic co‐adsorbents with the sensitizer, has been demonstrated to enhance the efficiency of dye‐sensitized solar cells (DSCs). Herein, the influence of the anchoring groups of the co‐adsorbents on the performance of the DSCs is carefully examined by selecting two model molecules: neohexyl phosphonic acid (NHOOP) and bis‐(3,3‐dimethyl‐butyl)‐phosphinic acid (DINHOP). The effect of these co‐adsorbents on the photovoltaic performance (J–V curves, incident photon‐to‐electron conversion efficiency) is investigated. Photoelectron spectroscopy and electrochemical impedance spectroscopy are performed to assess the spatial configuration of adsorbed dye and co‐adsorbent molecules. The photoelectron spectroscopy studies indicate that the ligands of the ruthenium complex, containing thiophene groups, point out away from the surface of TiO2 in comparison with the NCS group.

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“…[21] The electron take-off angle was 908. The samples were analyzed at a pressure in the range 10-10 mbar.…”

Section: Pes Characterizationmentioning

confidence: 99%

Molecular‐Scale Interface Engineering of Nanocrystalline Titania by Co‐adsorbents for Solar Energy Conversion

et al. 2012

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“…However, they indicate that epitaxial relationship between In and W can be expected. To get more information about the behaviour of indium on tungsten we employed imaging property of SCIENTA instrument [17]. Indium films of 2.0-2.8 ML thickness have been deposited on the area a little smaller than one half of the tungsten surface.…”

Section: Surface Diffusion Of In Atoms On the Polycrystalline Tungstementioning

confidence: 99%

Study of Ultrathin In-Ag Layers οn Tungsten by Means of Surface Spectroscopy Techniques

2008

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Auger electron spectroscopy, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, scanning tunnelling microscopy, low energy electron diffraction, and thermodesorption methods were used to investigate the process of growth of ultrathin In films and formation of In-Ag surface alloys on tungsten substrate. Several indium layers, having coverage ranging from 0.2 to 0.8 ML were deposited on tungsten substrate in room temperature. It was found that at the lowest coverages (Θ = 0.1-0.3 ML) indium atoms form (3 × 1) structure, characterized by very sharp low energy electron diffraction patterns. With increasing Θ they tend to form densely packed islands interpreted as slightly distorted In(111) monolayers. Surface diffusion of In onto the tungsten surface was studied by using ESCA imaging property of SCIENTA ESCA200 instrument. Measuring the photoelectron intensity as a function of two spatial coordinates and the energy, we observed movement of In atoms on the tungsten surface. On the basis of the change of surface coverage with distance surface the diffusion coefficient was evaluated at the temperature range of 400-700 K. Intermixing of ultrathin films of indium and silver, after their surface diffusion from the sample edges to the centre of the tungsten surface, were observed by using X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and the Auger electron spectroscopy methods. Intermixing was controlled by means of photoemission spectra from the valence states and the In 4d level, as well as by X-ray photoelectron spectroscopy studies of indium and silver core levels excited by Al Kα source.

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“…In the ESCA measurements Al Ka X-ray photons (1486.7 eV) generated from a rotating anode are used for the excitation of secondary electrons and of photoelectrons from Cs 3d and I 3d core levels. The ESCA-300 system is described in [32]. Briefly, we worked with an energy resolution of 0.30 eV and a lateral resolution of 27 pm, as determined by resolving lithographic microstructures.…”

Section: Csi Film Characterizationmentioning

confidence: 99%

“…Furthermore the lateral resolution is crucial in the study of insulators where local charging effects can easily induce artifacts in spatially integrated X-ray photoemission results [31]. Our study employed a laterally resolved Electron Spectroscopy for Chemical Analysis (ESCA-300) apparatus [32] and a Scanning Auger Microprobe (SAM) to investigate the lateral inhomogeneity of the surface stoichiometry of polycrystalline CsI films. To obtain the local quantum efficiency (QE) we measured the secondary electron photoemission by a Photoemission Electron Microscope both in PEEM mode (excitation by a nonmonochromatized deuterium lamp) and in XSEM mode (excitation by tunable X-ray synchrotron radiation source) [33].…”

Section: Introductionmentioning

confidence: 99%

Laterally resolved measurements of polycrystalline cesium iodide surfaces

Rudolf¹,

Marchal²,

Sporken³

et al. 1997

Nuclear Instruments and Methods in Physics Research Section A:

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Laterally resolved measurements of polycrystalline cesium iodide surfaces Rudolf, Petra; Marchal, F.; Sporken, R.; Caudano, R.; dellOrto, T.; Almeida, J.; Braem, A.; Piuz, F.; Sgobba, S.; Paic, G. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractThe aim of this work was to establish the correlation between the local chemical composition and morphology of polycrystalline cesium iodide (CsI) and its local quantum efficiency. We used a laterally resolved Electron Spectroscopy for Chemical Analysis (ESCA-300) apparatus and a Scanning Auger Microprobe (SAM) to investigate the lateral inhomogeneity of the CsI surface stoichiometry.The local quantum efficiency (QE) was determined by measuring the secondary electron emission in Photoemission Electron Microscopy both with a non-monochromatized deuterium lamp and with tunable X-ray synchrotron radiation as the excitation source. CsI films on different substrates were studied. We found that the local QE depends strongly on the morphology, on the local stoichiometry and on carbon contamination. The results allow for an optimisation of the quantum efficiency of large area photocathodes.

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A new ESCA instrument with improved surface sensitivity, fast imaging properties and excellent energy resolution

Cited by 275 publications

References 23 publications

Molecular‐Scale Interface Engineering of Nanocrystalline Titania by Co‐adsorbents for Solar Energy Conversion

Molecular‐Scale Interface Engineering of Nanocrystalline Titania by Co‐adsorbents for Solar Energy Conversion

Study of Ultrathin In-Ag Layers οn Tungsten by Means of Surface Spectroscopy Techniques

Laterally resolved measurements of polycrystalline cesium iodide surfaces

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