Structurally Tunable Self-Assembled 2D Cocrystals of C60 and Porphyrins on the Ag (110) Surface

Abstract

Due to the donor–acceptor nature of their supramolecular interactions, nanostructured porphyrin-fullerene self-assembled architectures show attractive properties that can be exploited in high efficiency solar cells. In this work, we show that six different ordered bicomponent porphyrin-fullerene (C60) networks are obtained by controlling the peripheral functionalization of meso-tetraphenylporphyrins (TPP) with amino groups and the stoichiometry of their aggregates with C60 on Ag (110). Such networks can be grouped in two general classes, depending on their structural habit: the so-called “stripes” phases, formed by alternating monomolecular stripes of C60 and TPP, and the so-called “pores” phases, where a fullerene net accommodates isolated TPP molecules in nanometer-sized pores. These phases are of general interest in the field of surface-supported electron donor–acceptor systems, since they represents a rare example of fullerene-containing surface-supported bicomponent supramolecular networks where the binary nanostructures are definitely more stable thermodynamically than the two separated single-component phases, thereby resembling three-dimensional TPP/C60 cocrystals. The thermodynamic stability in an extended temperature range has profound consequences on the degree of long-range order attainable in the self-assembly process.