Linear tuning of charge carriers in graphene by organic molecules and charge-transfer complexes

2010 ◽  
Vol 81 (15) ◽  
Author(s):  
J. T. Sun ◽  
Y. H. Lu ◽  
W. Chen ◽  
Y. P. Feng ◽  
A. T. S. Wee
Keyword(s):  
Charge Transfer ◽  
Organic Molecules ◽  
Charge Carriers ◽  
Charge Transfer Complexes

Encapsulating third donors into D-A hybrid heterostructures to form three-component charge-transfer complexes for enhanced electrical properties

2021 ◽  
Author(s):  
Meng-Hua Li ◽  
Ming-Hua You ◽  
Mei-Jin Lin
Keyword(s):  
Charge Transfer ◽  
Electrical Properties ◽  
Organic Molecules ◽  
Steric Effects ◽  
Charge Transfer Complexes ◽  
Coordination Sites ◽  
Component Charge

inorganic donors and organic acceptors. However, due to the steric effects of inorganic coordination sites, it is difficult for the large organic molecules to form compact packing at the molecule...

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

scholarly journals Semiconduction in charge-transfer complexes

1969 ◽  
Vol 47 (20) ◽  
pp. 3899-3902 ◽  
Author(s):  
S. N. Bhat ◽  
C. N. R. Rao
Keyword(s):  
Charge Transfer ◽  
Charge Carriers ◽  
Charge Transfer Complexes ◽  
Chloride Complexes ◽  
Seebeck Coefficients ◽  
Spin Resonance ◽  
Electrical Conductivities ◽  
Donor Acceptor ◽  
Ambient Gases ◽  
Antimony Chloride

Electrical conductivities, electron spin resonance spectra, electronic spectra, and Seebeck coefficients of solid charge-transfer complexes of benzidine–iodine, p-phenylenediamine–iodine, and phenothiazine–iodine as well as two antimony chloride complexes of phenothiazine have been studied. The phenothiazine–I2 system shows change in sign of the majority charge carriers with the donor–acceptor ratio. The effect of ambient gases on the conductivities of a few donors, acceptors, and their complexes in the solid state have been examined. Seebeck coefficient measurements show that the conduction in TCNQ salts takes place by a hopping mechanism.

Electronic Conduction in Polymers. III. Electronic Properties of Polypyrrole

1963 ◽  
Vol 16 (6) ◽  
pp. 1090 ◽  
Author(s):  
BA Bolto ◽  
R McNeill ◽  
DE Weiss
Keyword(s):  
Charge Transfer ◽  
Pyrolysis Temperature ◽  
Electron System ◽  
Charge Carriers ◽  
Charge Transfer Complexes ◽  
Spin Resonance ◽  
Broad Signal ◽  
Donor Nitrogen ◽  
P Type ◽  
Narrow Signal

The electron spin resonance absorption and electrical resistivity have been measured under rigorous conditions for a series of polypyrroles prepared over the temperature range 120-500�. When plotted as a function of pyrolysis temperature the resistivity shows a maximum in the region 200-300�. Although the resistivity of the polymers prepared at 120� and 500� is roughly similar, their e.s.r. behaviour is quite different. The low-temperature polymer, containing much complexed iodine, shows a very broad signal arising from an excited state probably associated with a polypyrrole-iodine charge-transfer complex; the high temperature polymer, containing no iodine, shows a strong narrow signal arising from the ground state of the polymer. The changes in conductivity of the polymers following the adsorption of electron acceptor or donor molecules have been measured. It is concluded that, depending on the relative amounts of electron donating or attracting chemisorbed species in relation to the concentration of donor nitrogen atoms in the polypyrrole, the polymer may behave as an intrinsic or extrinsic semiconductor with n- or p-type characteristics. Charge-transfer complexes of strength sufficient to cause partial ionization induce extrinsic behaviour by changing the ratio of the number of electrons to the number of holes. Substituent groups such as the hetero atoms which interact with the π-electron system inductively or through resonance affect only the relative mobility of the charge carriers and induce intrinsic behaviour.

Investigation of charge-transfer complexes formation between photoluminescent graphene oxide and organic molecules

Nanoscale ◽  
2012 ◽  
Vol 4 (2) ◽  
pp. 405-407 ◽  
Author(s):  
Guoqing Xin ◽  
Hongzhe Wang ◽  
Namhun Kim ◽  
Wontae Hwang ◽  
Sung Min Cho ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Charge Transfer ◽  
Organic Molecules ◽  
Charge Transfer Complexes

Direct imaging of charge transfer

1996 ◽  
Vol 54 ◽  
pp. 680-681
Author(s):  
Yimei Zhu ◽  
J. Tafto
Keyword(s):  
Charge Transfer ◽  
Electron Diffraction ◽  
Scattering Amplitude ◽  
High Temperature Superconductors ◽  
Charge Carriers ◽  
Image Charge ◽  
Net Charge ◽  
Long Time ◽  
Electron Holes ◽  
First Time

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.

Magnetic properties of new charge-transfer complexes based on manganese porphyrins

1997 ◽  
Vol 90 (3) ◽  
pp. 407-413
Author(s):  
MARC KELEMEN ◽  
CHRISTOPH WACHTER ◽  
HUBERT WINTER ◽  
ELMAR DORMANN ◽  
RUDOLF GOMPPER ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Charge Transfer ◽  
Charge Transfer Complexes ◽  
Manganese Porphyrins

Charge Transfer Complexation Boosts Molecular Conductance Through Fermi Level Pinning

2018 ◽  
Author(s):  
Kun Wang ◽  
Andrea Vezzoli ◽  
Iain Grace ◽  
Maeve McLaughlin ◽  
Richard Nichols ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Single Molecule ◽  
Quantum Interference ◽  
Transmission Function ◽  
Scanning Tunneling ◽  
Charge Transfer Complexes ◽  
Tunneling Microscopy ◽  
Quantum Interference Effect ◽  
Single Molecule Junctions ◽  
Charge Transfer Complexation

We have used scanning tunneling microscopy to create and study single molecule junctions with thioether-terminated oligothiophene molecules. We find that the conductance of these junctions increases upon formation of charge transfer complexes of the molecules with tetracyanoethene, and that the extent of the conductance increase is greater the longer is the oligothiophene, i.e. the lower is the conductance of the uncomplexed molecule in the junction. We use non-equilibrium Green's function transport calculations to explore the reasons for this theoretically, and find that new resonances appear in the transmission function, pinned close to the Fermi energy of the contacts, as a consequence of the charge transfer interaction. This is an example of a room temperature quantum interference effect, which in this case boosts junction conductance in contrast to earlier observations of QI that result in diminished conductance.<br>

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