Spectroscopy: Ultraviolet Photoelectron Spectroscopy (UPS)

Service description

Ultraviolet photoelectron spectroscopy (UPS) involves the measurement of kinetic energy spectra of photoelectrons emitted by molecules which have absorbed ultraviolet photons, in order to determine molecular orbital energies in the valence region. Photoelectron Spectroscopy Service is a general service of the Institute of Catalysis and Petrochemistry (https://icp.csic.es/services/research-support-services/xps/), whose main activity is the characterization of solid surfaces (identification of elements, information about their oxidation state and atomic concentration in the surface) by XPS (X-Ray Photoelectron Spectroscopy) and UPS (Ultraviolet Photoelectron Spectroscopy) techniques. This Service has a photoelectron spectroscopy system (SPECS) working under UHV, with energy analyzer PHOIBOS 150 9MCD, monochromatic and non-monochromatic X-ray sources (XPS analysis), flood gun for charge compensation, ultraviolet photon source (UPS analysis), ion-gun for depth profiling and and a high pressure chamber to perform reactions (HPC). This Service gives analytical support to CSIC scientists, as well as to Universities, Research Centres and Private Companies. In order to apply for an XPS, UPS and/or HPC+XPS analysis, it is necessary to fill in the "Application Form", which is available on the web page of the Service (https://icp.csic.es/services/research-support-services/xps/). This Form must be given together with the samples to the Technical Manager of the Service. Previously, it is necessary to read the "Guide" with information about how the Photoelectron Spectroscopy works, and also the "Rates" of the Service. Both documents are also available on the web page of the Service.

Service description

The XPS analysis Service is equiped with two instruments with different capabilities and aimed to different applications: 1.- A X-ray spectrometer devoted to the analysis of monolithic and "Thin Films" samples. This equipment consists of four interconected ultra high vacuum chambers: the analysis chamber, two preparation chambers and a load lock chamber. The analysis chamber is equiped with a SPEC PHOIBOS 100 hemispherical electron energy analyser and a DLD detector, and with different excitation sources: an acromatic dual X-ray source (Mgkalpha and Alkalpha), a Kimbal electron gun, an ion gun and an UV light source. With these sources, not only XPS analysis, but also UPS, ISS and REELS analyses can be carried out. Short noble gas ion etching and depth profile analysis can also be carried out. The reparation and load lock chambers are equiped with a resistive heater, several leak gas valves, a plasma source, ion sources, view ports and several Knudsen cells, for surface cleaning, chemical treatment, light irradiation or surface coating of the samples, in situ. Photoelectron Spectrometer for "powder Samples" and Gas Reactivity Cell (SPECS PHOIBOS 100, SPECS HPHT CELL), with the following: Analysis chamber, equipped with a multichannel hemispheric analyser (PHOIBOS 100), three axes manipulator, and dual X-ray source (Mgkalpha and Alkalpha). Reactivity Cell, (High Pressure and High Temperature) for treating the samples under controlled gas and vapour atmospheres, up to 200 bar and 800C (simultaneously). Both static and continous flow of gases are possible for those treatments. Samples in the form of powders or thin films can be treated in this chamber. A fast load chamber, where samples can be outgassed at mild temperatures (150C). Ion sputtering of samples to make a depth profiling is also possible under diferrent ion beams (Ar+, O2+, etc). Different additional accesories, such as Metal evaporators, UV-Vis sources can be incorporated if neccesary.