Tuning the Electronic Structure of Graphene by an Organic Molecule

2009 ◽  
Vol 113 (1) ◽  
pp. 2-5 ◽  
Author(s):  
Y. H. Lu ◽  
W. Chen ◽  
Y. P. Feng ◽  
P. M. He
Keyword(s):  
Electronic Structure ◽  
Organic Molecule

Organic Molecule Adsorption on Stepped Si–Au Surfaces: Role of Functional Group on Geometry and Electronic Structure

2019 ◽  
Vol 256 (7) ◽  
pp. 1800653
Author(s):  
Conor Hogan ◽  
Svetlana Suchkova ◽  
Friedhelm Bechstedt ◽  
Eugen Speiser ◽  
Sandhya Chandola ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Organic Molecule ◽  
Functional Group ◽  
Molecule Adsorption

D–A3 TADF emitters: the role of the density of states for achieving faster triplet harvesting rates

2019 ◽  
Vol 7 (41) ◽  
pp. 12942-12952 ◽  
Author(s):  
Julien Eng ◽  
Jerry Hagon ◽  
Thomas James Penfold
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Symmetry Breaking ◽  
Density Of States ◽  
Organic Molecule ◽  
Symmetry Breaking Dynamics ◽  
Triplet Harvesting

A D–A3 structure is used to enhance the triplet harvesting rate of a purely organic molecule. However, excited state symmetry breaking dynamics plays an detrimental role causing localisation of the electronic structure and reducing this rate.

Graphene field effect transistor as a probe of electronic structure and charge transfer at organic molecule–graphene interfaces

Nanoscale ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 1471-1478 ◽  
Author(s):  
Jiri Cervenka ◽  
Akin Budi ◽  
Nikolai Dontschuk ◽  
Alastair Stacey ◽  
Anton Tadich ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Field Effect ◽  
Organic Molecule ◽  
Field Effect Transistor ◽  
Nitrogen Heterocycles ◽  
Graphene Field Effect Transistor ◽  
Effect Transistor

The electronic structure of physisorbed molecules containing aromatic nitrogen heterocycles (triazine and melamine) on graphene is studied.

The Valence Electronic Structure of N-Doped P-Sexiphenyl

1999 ◽  
Vol 561 ◽  
Author(s):  
U. Theissl ◽  
E.J.W. List ◽  
N. Koch ◽  
A. Vollmer ◽  
S. Schrader ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Structure ◽  
Binding Energy ◽  
Alkali Metal ◽  
Photoelectron Spectroscopy ◽  
Organic Molecule ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Surface Yield ◽  
Valence Electronic Structure

ABSTRACTThin films of p-sexiphenyl (6P) were doped with increasing amounts of potassium in situ, and the change in the valence electronic structure of 6P upon the alkali metal deposition was followed with ultraviolet photoelectron spectroscopy. We observe the evolution of new intragap emissions, which are attributed to the formation of bipolarons, even for very low doping concentrations. The low binding energy intra-gap emission exhibits a pronounced asymmetric lineshape, in contrast to the findings when cesium is used as dopant. In order to investigate whether this lineshape is due to different emissive electronic species in the bulk and on the surface of the 6P film the take-off angle for the photoelectrons was varied. As no change in the lineshape is found when going from normal to near-grazing emission we can exclude that charged 6P molecules in the bulk and on the surface yield different valence electronic spectra. Therefore, the characteristic lineshape of the low binding energy emission is proposed to be related to the interaction of the doped organic molecule with the different counterions.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

1996 ◽  
Vol 54 ◽  
pp. 342-343
Author(s):  
S.J. Splinter ◽  
J. Bruley ◽  
P.E. Batson ◽  
D.A. Smith ◽  
R. Rosenberg
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Thin Layers ◽  
Nominal Composition ◽  
Spatially Resolved ◽  
Service Lifetime ◽  
Heat Treated ◽  
Probe Size ◽  
Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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