Discotic Liquid Crystals as Organic Semiconductors

Pisula, Wojciech; Müllen, Kläus

doi:10.1002/9783527671403.hlc145

Cited by 14 publications

(13 citation statements)

References 163 publications

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“…Besides alignment, charge transport is another important requirement for organic electronics. As has been summarised by Pisula and Müllen [7], both size and intracolumnar π-overlap matters in this respect. For example, hexathiohexyltriphenylene displays a hole mobility of 0.1 cm 2 V -1 s -1 , which is several orders of magnitude higher than those for the corresponding hexahexyloxytriphenylene (μ = 0.001 cm 2 V -1 s -1 ).…”

Section: Introductionmentioning

confidence: 85%

Playing with nanosegregation in discotic crown ethers: from molecular design to OFETs, nanofibers and luminescent materials

Baro

Wöhrle

Kirres

2016

Liquid Crystals Today

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Discotic liquid crystals are promising materials for electronic device applications. Combining extended π-systems with crown ethers may further open access to functional supramolecular hybrid materials. In the present publication, we briefly summarise recent literature developments and focus in a second part on our work in the field of discotic crown ethers. The crown ether derivatives are conveniently accessible by convergent syntheses which allow a high degree of variation with respect to side chains, mesogenic unit, size and symmetry of the crown core, metal complexation and counterion. This set of compounds provides a basis for systematic structureproperty relationship investigations. Numerous experimental studies identified factors being crucial for mesophase stabilisation and geometry and furthermore led to novel room-temperature crown ether mesogens. The latter were obtained by congestion of the mesogenic units and even introduction of peripheral δ-methyl branched side chains. The formation of molybdenum clustomesogens and their application as luminescent hybrid materials is also described.

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Section: Introductionmentioning

confidence: 85%

Playing with nanosegregation in discotic crown ethers: from molecular design to OFETs, nanofibers and luminescent materials

Baro

Wöhrle

Kirres

2016

Liquid Crystals Today

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“…Particular interest is presented by discotic mesogens formed by an aromatic nucleus surrounded by aliphatic chains that do not contain benzene rings. In such compounds, a large number of phase transitions are usually observed [9][10][11]. Therefore, disk-shaped systems are of great interest from the point of view of basic research in the physics and chemistry of liquid crystals.…”

Section: The Structure Of Discotic Liquid Crystalsmentioning

confidence: 99%

Phase Transitions in Liquid Crystals With Disk-Like and Graphene Molecules

Naskalova¹,

Larin²,

Кузнецова³

2018

Proceedings of the International Symposium “Engineering and Earth Sciences: Applied and Fundamental Research” (ISEES 2018)

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“…Columnar phases of discotic liquid crystals display one-dimensional (1D) photoconductivity according to a seminal discovery by Haarer et al in 1993 [1], turning the investigation of the electronic charge transport in columnar liquid crystals into a very active field of research [2,3]. Columnar materials can be used as semiconductors in applications, like organic field effect transistors (OFET) [4,5], organic light emitting diodes (OLED) [6], or organic photovoltaic cells (OPV) [7].…”

Section: Introductionmentioning

confidence: 99%

Improved Electronic Transport in Ion Complexes of Crown Ether Based Columnar Liquid Crystals

et al. 2019

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The Li+- and K+-complexes of new discotic mesogens, where two n-alkoxy-substituted triphenylene cores are connected by a central crown ether (12-crown-4 and 18-crown-6), provide interesting structural and electronic properties. The inter- and intra-columnar structure was investigated by small and wide angle X-ray scattering. The electronic and ionic transports were studied by temperature dependent photoconductivity and impedance spectroscopy, respectively. Besides a strong increase of the stability and the width of the columnar phases the presence of soft anions (iodide, thiocyanate, tetrafluoroborate) leads to an improved intra-columnar order. The hereby shortened stacking-distance of the triphenylene cores leads to a significant increase of the photoconductivity in the columnar mesophase. Furthermore, the ionic conductivity of the new materials was investigated on macroscopically aligned thin films. The existence of channels for fast cation transport formed by the stacked crown ether moieties in the centre of each column can be excluded. The cations are coordinated strongly and therefore contributing only little to the conductivity. The ionic conductivity is dominated by the anisotropic migration of the non-coordinated anions through the liquid, like side chains favouring the propagation parallel to the columns. Iodide migrates about 20 times faster than thiocyanate and 100 times faster than tetrafluoroborate.

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Discotic Liquid Crystals as Organic Semiconductors

Cited by 14 publications

References 163 publications

Playing with nanosegregation in discotic crown ethers: from molecular design to OFETs, nanofibers and luminescent materials

Playing with nanosegregation in discotic crown ethers: from molecular design to OFETs, nanofibers and luminescent materials

Phase Transitions in Liquid Crystals With Disk-Like and Graphene Molecules

Improved Electronic Transport in Ion Complexes of Crown Ether Based Columnar Liquid Crystals

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