Ordered Architectures of a Soluble Hexa-<i>p</i><i>eri</i>-hexabenzocoronene−Pyrene Dyad:  Thermotropic Bulk Properties and Nanoscale Phase Segregation at Surfaces

Tchebotareva, Natalia; Yin, Xiaomin; Watson, Mark D.; Samorı́, Paolo; Rabe, Jürgen P.; Müllen, Kläus

doi:10.1021/ja028609i

Cited by 88 publications

(86 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A requirement for good mobility in films of organic conjugated molecules is a good overlap of the π-electrons of neighboring molecules. Many pathways are being explored to achieve self-assembled highly connected networks of π-π interacting molecules, including both chemical modifications [2][3][4] and processing techniques. [5][6][7][8][9][10][11][12] Discotics, i.e., planar, disc-shaped aromatic molecules, have been intensely studied during the past two decades.…”

Section: Introductionmentioning

confidence: 99%

In Situ Studies of Phase Transitions in Thin Discotic Films

et al. 2005

Self Cite

View full text Add to dashboard Cite

The crystalline to liquid crystalline (Cr-LC) phase transition in thin films of zone-cast hexa-perihexabenzocoronene sixfold substituted with dodecyl side chains (HBC-C 12 H 25 ) has been studied in detail using grazing incidence X-ray diffraction (GID), electron diffraction (ED), and variable angle spectroscopic ellipsometry (VASE), When heating the material, a first minor transition is observed around 42°C. This change is attributed to alterations of the crystalline alkyl chain packing, which only slightly changes the electronic properties of the material. At higher temperatures of about 90°C, but still significantly below the previously reported transition temperature in bulk, the Cr-LC transition is observed. An accompanying large increase in optical anisotropy is compatible with the X-ray data, showing a transition from the as-cast herringbone-like crystalline state to a highly ordered discotic hexagonal columnar LC phase. The structural transition has the macroscopic effect of increasing the film thickness. The high structural order of the as-cast low-temperature phase is only partly recovered after cooling, and the phase transition exhibits a large hysteresis. From the ellipsometry data, the dielectric tensor of HBC-C 12 H 25 was refined to unprecedented detail. IntroductionOrganic electronics have promising prospects, with the main motivation being to make cheap plastic sensors and circuits. 1 The importance of well-defined molecular order to exploit the highly anisotropic properties of the specifically designed molecules is well-recognized. A requirement for good mobility in films of organic conjugated molecules is a good overlap of the π-electrons of neighboring molecules. Many pathways are being explored to achieve self-assembled highly connected networks of π-π interacting molecules, including both chemical modifications 2-4 and processing techniques. [5][6][7][8][9][10][11][12] Discotics, i.e., planar, disc-shaped aromatic molecules, have been intensely studied during the past two decades. To make them soluble and to control the thermal properties, they are substituted with side chains at the periphery. The molecules tend to segregate into stacked columns of the aromatic cores, separated by less-ordered side chains. These stacks can be considered one-dimensional molecular wires, whereas the side chains, typically alkyl, are electronically inactive. A relatively high mobility of typically 1.0 cm 2 /V s is obtained in these materials. 13 The molecules studied here, hexa-peri-hexabenzocoronenes (HBC; see Figure 1) are graphenes, having delocalized electrons on both sides of the molecular plane. Underivated HBC is highly crystalline and poorly soluble. Because of electrostatic quadrupolar interactions, the molecules tend to pack in the so-called herringbone structure.

show abstract

Section: Introductionmentioning

confidence: 99%

In Situ Studies of Phase Transitions in Thin Discotic Films

et al. 2005

Self Cite

View full text Add to dashboard Cite

show abstract

“…In recent years, synthetic strategies of p-n dyad molecules have shown attractive systems and some of them exhibit mesomorphism [67][68][69][70][71][72][73]. These also would be interesting candidatures for the active layer in organic photovoltaics.…”

Section: Discussionmentioning

confidence: 99%

Discotic Liquid Crystalline Blends for Nano-Structure Formation Toward Bulk Heterojunction Active Layer in Organic Photovoltaics

Shimizu

2014

Nanoscience With Liquid Crystals

View full text Add to dashboard Cite

Liquid crystalline semiconductor is a new category of organic semiconductors and lots of studies on the materials and application to electronic devices have been carried out. In particular, organic thin film photovoltaics is an interesting research field by use of liquid crystalline semiconductors because of the characteristic properties of liquid crystals. In this chapter, the miscibility in liquid crystals and the related issues on the application of liquid crystalline semiconductors are overviewed to give an insight for their possible contribution to the drastic improvement of organic photovoltaics technology including the fabrication by printed electronics.

show abstract

“…For improvement in the performance of bulk heterojunction organic solar cells, the incorporation of p-type and n-type segments in a single molecule was sought. Accordingly, molecular DLC dyads such as HBC-pyrene [162], HBC-anthraquinone [163] and HBC-perylenetetracarboxy diimide [93] were reported. Although OPV cells employing discotic molecules are yet to match the performance of polymer based devices, the progress that we are making with respect to the synthesis of new molecules and design of novel molecular architectures has been very encouraging.…”

Section: Applications Of Discotic Columnar Semiconductorsmentioning

confidence: 99%

Self-assembled 1D Semiconductors: Liquid Crystalline Columnar Phase

Mathews

Achalkumar

2015

Anisotropic Nanomaterials

View full text Add to dashboard Cite

Organic semiconducting materials have emerged as potential alternative to inorganic silicon based semiconductors for the production of low-cost, flexible and light weight plastic electronic devices. When compared with crystalline and polymeric structures, liquid crystalline (LC) ordering in organic semiconductors favors their self-assembly into large area monodomain thin-film structures with carrier mobilities in the range from 10

show abstract

Ordered Architectures of a Soluble Hexa-peri-hexabenzocoronene−Pyrene Dyad: Thermotropic Bulk Properties and Nanoscale Phase Segregation at Surfaces

Cited by 88 publications

References 34 publications

In Situ Studies of Phase Transitions in Thin Discotic Films

In Situ Studies of Phase Transitions in Thin Discotic Films

Discotic Liquid Crystalline Blends for Nano-Structure Formation Toward Bulk Heterojunction Active Layer in Organic Photovoltaics

Self-assembled 1D Semiconductors: Liquid Crystalline Columnar Phase

Contact Info

Product

Resources

About