SRPES spectroscopy

Accurate investigation of the valence ionization spectra is important subject to elucidate the electronic structure of molecules. Ionization spectra of five-membered aromatic compounds have also been intensively studied. The high-resolution synchrotron radiation photoelectron spectra (SRPES) of furan and thiophene were measured and analyzed with asymmetry parameter up to about 40 eV [63,64]. The electron momentum spectroscopy (EMS) was also applied to furan up to 30-40 eV [65]. The ionization spectra of these molecules were also studied by several theoretical methods. However, there were some controversial assignments even for the outer-valence region, in particular for the peak position of Ibi(TTi) state and the inner-valence spectra have not been theoretically reproduced. 

Among the related methods, specific experimental designs for applications are emphasized. As in-system synchrotron radiation photoelectron spectroscopy (SRPES) will be applied below for chemical analysis of electrochemically conditioned surfaces, this method will be presented first, followed by high-resolution electron energy loss spectroscopy (HREELS), photoelectron emission microscopy (PEEM), and X-ray emission spectroscopy (XES). The latter three methods are rather briefly presented due to the more singular results, discussed in Sections 2.4-2.6, that have been obtained with them. Although ultraviolet photoelectron spectroscopy (UPS) is an important method to determine band bendings and surface dipoles of semiconductors, the reader is referred to a rather recent article where all basic features of the method have been elaborated for the analysis of semiconductors [150]. 

Figure 2.26 Schematic of the SoLiAS used for SRPES at BESSY level 1 is the conditioning level with the electrochemical vessel (EC see Figure 2.27) attached, facilities for etching, and a buffer chamber (BC) for outgassing of samples that underwent wet treatments after transfer to the manipulator M, measurement levels 2 and 3 can be assessed at level 2, UPS LEED and quadrupole mass spectroscopy (QMS)...

The use of surface-sensitive techniques for the development of photoelectrochemical devices that convert solar energy has been described. The essence of this approach is the control of interfacial properties. This is achieved by a combination of empirical procedures that are developed into directed approaches of interface modification for desired electronic, chemical, and structural properties by a feedback between preparation and analysis. Besides the multitude of commercially available surface analytical techniques employed (AFM, STM, TEM, HRSEM, HREELS, SRPES, FTIR), novel methods have been developed such as Brewster angle refiectometry and stationary microwave reflectivity. The detailed highly surface-sensitive analysis of the surface chemistry of samples where electrochemical currents have passed has become possible by the development of in-system photoelectron spectroscopy and HREELS. 

The photoelectron emission spectroscopies (UPS/UPES, XPS/XEPS DSPES, SRPES, SECSA, FED, ARPS/ARPES)... 

SRPES synchrotron radiation photoelectron spectroscopy. For photon energies less than 300 eV also SXPS soft X-ray photoelectron spectroscopy. 

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