Development of Fullerene Thin-Film Assemblies and Fullerene-Diamine Adducts towards Practical Nanocarbon-Based Electronic Materials

Fullerenes are attractive spherical aromatic molecules with good electron acceptor capabilities and good utility as an n-type organic semiconductor. By using a fullerene-amine addition reaction, it was possible to fabricate ultrathin-film assemblies of fullerene on the surface of substrates, which were confirmed by photoelectric conversion applications. Addition reactions between fullerenes and primary aliphatic diamines can also occur to form insoluble adduct particles consisting of fullerenes and diamines. In one example, C-60-ethylenediamine adduct particles can be solubilized by addition of alkylacid chloride to residual amino groups of the adducts. Spin-coated or dip-coated thin-films of C-60-ethylenediamine adducts from their solutions are useful as n-type organic semiconductors which was confirmed with solar cell application. In this account, the history of the fabrication and application of fullerene thin-film assemblies and fullerene-diamine adducts using the fullerene-amine addition reaction is introduced and summarized from the early studies to more recent developments.