Modulation of Electronic Properties in Neutral and Oxidized Oligothiophenes Substituted with Conjugated Polyaromatic Hydrocarbons

Organic electronics offer exciting new alternatives to traditional inorganic devices based on advantages such as lower cost, ease of manufacture and flexibility. Small molecule semiconductors such as pentacene and rubrene are the focus of intense research due to performance approaching that of inorganic semiconductors. Charge transfer in polyaromatic hydrocarbons (PAHs) relies on the degree of π-conjugation and overlap of the π-systems of neighbouring molecules in the solid state. Small changes in the intermolecular interactions can lead to important changes in crystal packing and electronic properties. Thus, functionalization of PAHs is often used to improve their packing in the solid state. The addition of electronegative atoms into the ring system of pentacene has been proposed for improving stability while retaining attractive properties. [1] N-heteroacenes result from the substitution of nitrogen into the arene ring structure. The resulting potential for weak hydrogen bonding could direct coplanar molecular arrangements, sheet formation and favourable π-overlap for charge transport. Theoretical studies [2] have been carried out showing promising properties at the molecular level. As of yet no analysis of the solid state of these molecules has been performed to investigate how this substitution affects the packing and electronic properties. Here, we present the results of crystal structure prediction studies and calculation of charge transport properties aimed at understanding the influence of nitrogen substitution on the crystal packing of N-heteropentacenes and their performance as semiconducting materials.

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Strategies toward phosphorus-containing PAHs and the effect of P-substitution on the electronic properties

Pure and Applied Chemistry ◽

10.1515/pac-2016-0909 ◽

2017 ◽

Vol 89 (3) ◽

pp. 341-355 ◽

Cited By ~ 6

Author(s):

Rózsa Szűcs ◽

François Riobé ◽

Aude Escande ◽

Damien Joly ◽

Pierre-Antoine Bouit ◽

...

Keyword(s):

Electronic Properties ◽

Polyaromatic Hydrocarbons ◽

Theoretical Calculations ◽

Theoretical Perspective ◽

Fine Tuning ◽

Phosphorus Containing ◽

Organophosphorus Derivatives

AbstractIn this paper, we report on the different synthetic strategies which led to the preparation of a whole family of polyaromatic hydrocarbons containing a P-atom at the edge. In particular, we show from both experimental and theoretical perspective how the Scholl method has to be adapted to the specificity of organophosphorus derivatives. The P-modified PAHs possess the classical phosphane reactivity that allows fine-tuning of their electronic properties as evidenced by spectro-electrochemistry and theoretical calculations. In particular, the effect of P-substitution on the aromaticity of the different cycles of the PAH was studied.

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BN-Substituted coronene diimide donor–acceptor–donor triads: photophysical, (spectro)-electrochemical studies and Lewis behavior

Journal of Materials Chemistry C ◽

10.1039/d1tc03034e ◽

2021 ◽

Author(s):

Jonas Hoffmann ◽

Denis Jacquemin ◽

Muriel Hissler ◽

Anne Staubitz

Keyword(s):

Electronic Properties ◽

Polyaromatic Hydrocarbons ◽

Molecular Structures ◽

Electrochemical Studies ◽

Donor Acceptor ◽

Boron Nitrogen

Boron/nitrogen substituted polyaromatic hydrocarbons (PAHs) are unique materials, with similar molecular structures to their carbon/carbon analogs, but different electronic properties.

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Structural properties of GaAs/InGaAs/GaAs (001) and InGaAs/GaAs (001) heterostructures and correlation with electronic properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176149 ◽

1990 ◽

Vol 48 (4) ◽

pp. 602-603

Author(s):

J.M. Bonar ◽

R. Hull ◽

R. Malik ◽

R. Ryan ◽

J.F. Walker

Keyword(s):

Band Gap ◽

Electronic Properties ◽

Gaas Substrate ◽

Critical Thickness ◽

Lattice Mismatch ◽

Band Offset ◽

Misfit Dislocations ◽

Gaas Substrates ◽

Gaas Structure ◽

Low X

In this study we have examined a series of strained heteropeitaxial GaAs/InGaAs/GaAs and InGaAs/GaAs structures, both on (001) GaAs substrates. These heterostructures are potentially very interesting from a device standpoint because of improved band gap properties (InAs has a much smaller band gap than GaAs so there is a large band offset at the InGaAs/GaAs interface), and because of the much higher mobility of InAs. However, there is a 7.2% lattice mismatch between InAs and GaAs, so an InxGa1-xAs layer in a GaAs structure with even relatively low x will have a large amount of strain, and misfit dislocations are expected to form above some critical thickness. We attempt here to correlate the effect of misfit dislocations on the electronic properties of this material.The samples we examined consisted of 200Å InxGa1-xAs layered in a hetero-junction bipolar transistor (HBT) structure (InxGa1-xAs on top of a (001) GaAs buffer, followed by more GaAs, then a layer of AlGaAs and a GaAs cap), and a series consisting of a 200Å layer of InxGa1-xAs on a (001) GaAs substrate.

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