Structural Requirements for Surface-Induced Aromatic Stabilization

2014 ◽  
Vol 1647 ◽  
Author(s):  
Takuya Hosokai ◽  
Keiichirou Yonezawa ◽  
Kengo Kato ◽  
Rintaro Makino ◽  
Jinpeng Yang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Synchrotron Radiation ◽  
Aromatic Hydrocarbon ◽  
Photoelectron Spectroscopy ◽  
Functional Group ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Organic Metal ◽  
Structural Requirement ◽  
Structural Requirements ◽  
Aromatic Stabilization

ABSTRACTSurface-induced aromatic stabilization (SIAS), a recently proposed mechanism leading to a formation of charge-transfer (CT) states at organic/metal (O/M) interfaces [G. Heimel, et al., Nat. Chem.5, 187 (2013)], was investigated for an aromatic hydrocarbon, diindenoperylene (DIP), by means of synchrotron radiation-based ultraviolet photoelectron spectroscopy (UPS). By employing DIP and noble metal substrates (Ag and Cu), we confirmed the formation of CT states, indicating that an inclusion of a specific functional group with a hetero-atom within adsorbate molecules as suggested before is not necessarily required for the formation of CT states mediated by the SIAS. With a comparison of the mother and analogue molecules, perylene and PTCDA, we discuss the structural requirement for the realization of the SIAS.

scholarly journals Фотоэмиссионные исследования электронной структуры GaN, выращенного методом молекулярно-пучковой эпитаксии с плазменной активацией азота

2019 ◽  
Vol 61 (12) ◽  
pp. 2294
Author(s):  
С.Н. Тимошнев ◽  
А.М. Мизеров ◽  
Г.В. Бенеманская ◽  
С.А. Кукушкин ◽  
А.Д. Буравлев
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Synchrotron Radiation ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Experimental Studies ◽  
Surface States ◽  
Li Adsorption ◽  
Semiconductor Character

The results of experimental studies of the electronic and photoemission properties of an epitaxial GaN layer grown on a SiC/Si(111) substrate by plasma assisted molecular beam epitaxy are presented. The electronic structure of the GaN surface and ultrathin Li/GaN interface was first studied in situ under ultrahigh vacuum conditions under different Li coverages. The experiments were performed using photoelectron spectroscopy with synchrotron radiation in the photon energy range of 75–850 eV. The photoemission spectra in the region of the valence band and surface states and the photoemission spectra from the N 1s, Ga 3d, Li 2s core levels were studied for different submonolayer Li coverages. It is established that Li adsorption causes significant changes in the general form of the spectra induced by charge transfer between the Li layer and the lower N and Ga layers. It is established that the GaN surface has predominantly N-polarity. The semiconductor character of the Li / GaN interface is shown.

The Electronic Structure and the Energy Level Alignment at the Interface Between Organic Molecules and Metals

2006 ◽  
Vol 965 ◽  
Author(s):  
Eiji Kawabe ◽  
Hiroyuki Yamane ◽  
Kenji Koizumi ◽  
Ryohei Sumii ◽  
Kaname Kanai ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Energy Level ◽  
Photoelectron Spectroscopy ◽  
Organic Molecules ◽  
Interface States ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Energy Level Alignment ◽  
Tetracarboxylic Dianhydride

ABSTRACTWe investigated the electronic structure and the energy level alignment at the interfaces between perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and metals (Au, Cu and Co) by ultraviolet photoelectron spectroscopy (UPS). In the case of PTCDA/Au interface, the apparent interface states and charge transfer (CT) states were not observed in its UPS spectra. In the case of PTCDA/Cu and Co interfaces, however, we found that the CT from metal to PTCDA occurred, and that the apparent CT states were observed at PTCDA/Cu interface.

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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