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A series of amphiphilic molecules consisting of oligo(phenylene vinylene) (OPV) asymmetrically end-substituted with a hydrophilic poly(ethylene glycol) (PEG) segment and a hydrophobic alkyl chain is synthesized. This amphiphilic structure induces self-assembly into both thermotropic and lyotropic lamellar liquid crystalline (LC) phases.

Highly uniaxial alignment of [pi]-conjugated oligo(p-phenylenevinylene)s is achieved in the as-cast films by spin-coating the solution onto mechanically rubbed polymer alignment layers such as poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT:PSS) film. Its application to organic photovoltaic devices has achieved a high anisotropy in photosensitivity.

We report a new type of ordered monolayer for the surface modification of organic semiconductors. Fullerene derivatives with fluorocarbon chains ([6,6]-phenyl-C61-buryric acid 1H,1H-pertluoro-1-alkyl ester or FCC) spontaneously segregated as a monolayer on the surface of a [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) film during a spin-coating process from the mixture solutions, as confirmed by X-ray photoelectron spectroscopy (XPS). Ultraviolet photoelectron spectroscopy (UPS) showed the shift of ionization potentials (IPs) depending on the fluorocarbon chain length, indicating the formation of surface dipole moments. Surface-sensitive vibrational spectroscopy, sum frequency generation (SFG) revealed the ordered molecular orientations of the C60 moiety in the surface FCn layers. The intensity of the SFG signals from FCn on the surface showed a clear odd-even effect when the length of the fluorocarbon chain was changed. This new concept of the surface-segregated monolayer provides a facile and versatile approach to modifying the surface of organic semiconductors and is applicable to various organic optoelectronic devices. [ABSTRACT FROM AUTHOR]

The article offers information on a study on the synthesis of all-conjugated diblock copolymers (BCPs) by quasi-living polymerization and observation of their microphase separation. It states that in developing high-performance polymer devices it is of crucial value to control the nanostructures of semiconducting polymers. One of the strategies employed in this concern is to develop BCPs which contain semiconducting polymer segments.