Flat-on ambipolar triphenylamine/C-60 nano-stacks formed from the self-organization of a pyramid-sphere-shaped amphiphile

Abstract

A giant amphiphile, which is constructed with an amorphous nano-pyramid (triphenylamine, TPA) and a crystalline nano-sphere (C-60), was synthesized. Structural characterization indicates that this pyramid-sphere-shaped amphiphile (TPA-C-60) forms a solvent-induced ordered phase, in which the two constituent units self-assemble into alternating stacks of two-dimensional (2D) TPA and C-60 nanosheets. Due to the complexity of the molecular structure and the amorphous nature of the nano-pyramid, phase formation was driven by intermolecular C-60-C-60 interactions and the ordered phase could not be reformed from the TPA-C-60 melt. Oriented crystal arrays of TPA-C-60, which contain flaton TPA/C-60 nano-stacks, can be obtained via a PDMS-assisted crystallization (PAC) technique. The flaton dual-channel supramolecular structure of TPA-C-60 delivered ambipolar and balanced charge-transport characteristics with an average me of 2.11 x 10(-4) cm(2) V-1 s(-1) and mh of 3.37 x 10(-4) cm(2) V-1 s(-1). The anisotropic charge-transport ability of the pyramid-sphere-shaped amphiphile was further understood based on the lattice structure and the lattice orientation of TPA-C-60 revealed from electron diffraction analyses.