Calculation of Energy Level Alignment and Interface Electronic Structure in Molecular Junctions beyond DFT

2021 ◽  
Author(s):  
Enrique Montes ◽  
Héctor Vázquez
Keyword(s):  
Electronic Structure ◽  
Energy Level ◽  
Molecular Junctions ◽  
Energy Level Alignment

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.

A New Alternative for the Low-Workfunction Electrode in Organic Devices

1999 ◽  
Vol 598 ◽  
Author(s):  
Norbert Koch ◽  
Egbert Zojer ◽  
Aparna Rajagopal ◽  
Jacques Ghijsen ◽  
Robert L. Johnson ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Energy Level ◽  
Strong Interaction ◽  
Photoelectron Spectroscopy ◽  
Organic Material ◽  
Photoelectron Spectra ◽  
Covalent Bonds ◽  
Light Emitting ◽  
Energy Level Alignment ◽  
Organic Devices

ABSTRACTThe application of ele ctroactive organic materials in devices (light emitting diodes, photovoltaic cells) often requires electrodes with a low workfunction. Commonly, aluminum or alkaline earth metals are used, which usually exhibit strong interaction with the organic material, such as the formation of new covalent bonds or doping. This results in a strong modification of the electronic structure of the organic/metal interface, and in most cases does not yield the energy level alignment expected for the unreacted interface. As a n alternative to the above-mentioned metals we propose the use of samarium, with a workfunction of 2.7 eV, for the following reason: we have studied the interface formation between Sm and p -sexiphenyl (6P, which exhibits intense blue electroluminescence), with ultraviolet photoelectron spectroscopy. Sm was deposited stepwise onto thin films of 6P in ultrahigh vacuum, and the photoelectron spectra were recorded after each step. We did not find any indication for a strong interaction between the two materials. Metallic Sm is formed instantaneously and the valence electronic structure of 6P remains unchanged upon the metal deposition. The weak interaction at this interface allows one to determine the energy level alignment between a metal and an organic material in a direct manner from the photoelectron spectra, without the need for making any assumptions on the workfunction or ionization potential.

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