Valence band spectroscopy on lignin

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Lothar Klarhöfer ◽  
Burkhard Roos ◽  
Wolfgang Viöl ◽  
Oliver Höfft ◽  
Stefan Dieckhoff ◽  
...  

Abstract The valence band of lignin and sputtered lignin was studied by X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and metastable induced electron spectroscopy (MIES). The corresponding spectra were compared with those from fingerprint molecules, representing the various chemical groups of lignin. The results of this analysis show that valence band spectroscopy, in particular a combination of XPS, UPS and MIES, allows an identification of hydroxyl, methoxy and phenyl groups at the lignin surface.

1999 ◽  
Vol 598 ◽  
Author(s):  
E. Ito ◽  
N. Koch ◽  
H. Oji ◽  
H. Ishii ◽  
G. Leising ◽  
...  

ABSTRACTMetal deposition on a p-sexiphenyl (6P) film was studied by ultraviolet photoelectron spectroscopy (UPS), metastable atom electron spectroscopy (MAES), and X-ray photoelectron spectroscopy (XPS). The deposited metals were Au, Mg, and several alkali metals (K, Na, Rb, and Cs). No chemical reaction between 6P and Au or Mg was observed in the measured spectra, while additional gap states appeared in the UPS and MAES spectra by deposition of the alkali metals. The diffusion of Au and Mg atoms into the 6P film was observed in the MAES spectra. We found the trend of the vacuum level shift is different between the systems of the 6P on the Au and its reversed systems (Au on the 6P film), suggesting the different formation of the interface depending on the deposition sequence.


2002 ◽  
Vol 09 (01) ◽  
pp. 425-430 ◽  
Author(s):  
TAKAHIRO YOKOYAMA ◽  
HISAO ISHII ◽  
YUKIO OUCHI ◽  
DAISUKE YOSHIMURA ◽  
KAZUHIKO SEKI ◽  
...  

The interface of the tris (8-hydroxyquinoline) aluminum ( Alq 3)/ LiF/Al system was investigated with ultraviolet photoelectron spectroscopy (UPS), metastable atom electron spectroscopy (MAES), and X-ray photoelectron spectroscopy (XPS). Strong chemical interaction was observed at Alq 3 on Al interface. By inserting a LiF layer, this interaction is suppressed and interface energy level alignment is changed to reduce a barrier for electron injection. The enhancement of device efficiency is ascribed to these phenomena. The importance of the combined use of various techniques on the same interface is stressed.


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