Amphiphilic Molecular Design as a Rational Strategy for Tailoring Bicontinuous Electron Donor and Acceptor Arrays: Photoconductive Liquid Crystalline Oligothiophene−C₆₀ Dyads

Abstract

For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study.

Design amphiphilic dipolar π-systems for stimuli-responsive luminescent materials using metastable states

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Controlling the crystalline three-dimensional order in bulk materials by single-wall carbon nanotubes

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Ambipolar-transporting coaxial nanotubes with a tailored molecular graphene–fullerene heterojunction

“…In 2004, Würthner et al (11) reported that selfassembly of a hydrogen-bonded D-A-D triad consisting of oligo(p-phenylene vinylene) (D) and perylenediimide (A) affords photoconductive nanofibers. To realize selective formation of bicontinuous D/A arrays in bulk, an amphiphilic oligothiophene-C 60 covalent D-A dyad with a liquid crystalline character has been developed (12). Dye-sensitized wet solar cells have been prepared by a modification of electrodes through layer-bylayer assembly of oligo(p-phenylene)/naphthalenediimide (13) and porphyrin/C 60 (14), designed to form a heterojunction.…”