Photoemission Study of Metal-Deposited p-Sexiphenyl Film

1999 ◽  
Vol 598 ◽  
Author(s):  
E. Ito ◽  
N. Koch ◽  
H. Oji ◽  
H. Ishii ◽  
G. Leising ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Alkali Metals ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Level Shift ◽  
Vacuum Level ◽  
X Ray ◽  
Photoemission Study ◽  
Gap States

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.

THE EFFECT OF A LiF LAYER ON Al/LiF/Alq3 INTERFACES STUDIED WITH ELECTRON SPECTROSCOPIES

2002 ◽  
Vol 09 (01) ◽  
pp. 425-430 ◽  
Author(s):  
TAKAHIRO YOKOYAMA ◽  
HISAO ISHII ◽  
YUKIO OUCHI ◽  
DAISUKE YOSHIMURA ◽  
KAZUHIKO SEKI ◽  
...  
Keyword(s):  
Energy Level ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Chemical Interaction ◽  
Electron Injection ◽  
Interface Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
X Ray ◽  
Combined Use ◽  
Device Efficiency

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.

Valence band spectroscopy on lignin

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Lothar Klarhöfer ◽  
Burkhard Roos ◽  
Wolfgang Viöl ◽  
Oliver Höfft ◽  
Stefan Dieckhoff ◽  
...  
Keyword(s):  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
X Ray ◽  
Chemical Groups

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.

Energy Level Alignment at Tpd/Etal Interfaces Studied by Kelvin Method

1999 ◽  
Vol 558 ◽  
Author(s):  
N. Hayashi ◽  
E. Ito ◽  
H. Ishii ◽  
Y. Ouchi ◽  
K. Seki
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metal Substrate ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Level Shift ◽  
Organic Metal ◽  
Metal Interface ◽  
Kelvin Probe ◽  
Vacuum Level ◽  
Initial Stage ◽  
Kelvin Probe Method

ABSTRACTThe vacuum level shift A was determined by Kelvin probe method for TPD/metal systems prepared in ultrahigh vacuum (TPD: N, N'-bis(3-methylphenyl)-N, N'-diphenyl-[1, 1'-biphenyl]-4,4'-diamine). The energy of the vacuum level sharply changed at the initial stage of depositing TPD on the metal substrates, and further bending was not observed up to 100 nm thickness of TPD. This result is consistent with our previous studies of ultraviolet photoelectron spectroscopy. These results indicate the invalidity of traditional model with a common vacuum level at organic/metal interface. We discussed the dependence of the vacuum level shift on the work function Φm of the metal substrate (Au, Cu, Ag, Mg, and Ca). A liner correlation between Δ and Φm was observed only in the region of 3.8 eV < Φm < 4.5 eV, indicating that Fermi level alignment is not achieved at least for some interfaces. We found that Δ for TPD film on the air-exposed metal substrate is smaller than that of TPD on clean metals and was observed a liner relation between Φm and Δ except for the Cu substrate.

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