Rubrene-Directed Structural Transformation of Fullerene (C60) Microsheets to Nanorod Arrays with Enhanced Photoelectrochemical Properties

One-dimensional (1D) nanostructures possess huge potential in electronics and optoelectronics, but the axial alignment of such 1D structures is still a challenging task. Herein, we report a simple method that enables two-dimensional (2D) C-60 microsheets to evolve into highly ordered nanorod arrays using rubrene as a structure-directing agent. The structural transformation is accomplished by adding droplets of rubrene-m-xylene solution onto C-60 microsheets and allowing the m-xylene solvent to evaporate naturally. In sharp contrast, when rubrene is absent from m-xylene, randomly oriented C-60 nanorods are produced. Spectroscopic and microscopic characterizations collectively indicate a rather plausible transformation mechanism that the close lattice match allows the epitaxial growth of rubrene on C-60 microsheets, followed by the reassembly of dissolved C-60 along the aligned rubrene due to the intermolecular charge-transfer (CT) interactions, leading to the formation of ordered nanorod arrays. Due to the aligned structures and the CT interactions between rubrene and C-60, the photocurrent density of the nanorod arrays is improved by 31.2% in the UV region relative to the randomly oriented counterpart. This work presents a facile and effective strategy for the construction of ordered fullerene nanorod arrays, providing new ideas for the alignment of fullerene and other relevant organic microstructures.

Automated summary

This study presents a simple method using rubrene as a structure-directing agent to transform 2D C-60 microsheets into highly ordered nanorod arrays. The results suggest that the intermolecular charge-transfer interactions between rubrene and C-60 enable the reassembly of dissolved C-60 into ordered nanorod arrays. The aligned structures and charge-transfer interactions contribute to a 31.2% improvement in photocurrent density of the nanorod arrays in the UV region compared to randomly oriented counterparts.