From C60 "trilliumons" to "trilliumenes:" Self-assembly of 2D fullerene nanostructures on metal-covered silicon and germanium

Spatially Confined Face-Selective Growth of Large-Area 2D Organic Molecular Crystals in a Supramolecular Gel for Highly Efficient Flexible Photodetection

2D organic molecular crystals (2DOMCs) are promising materials for the fabrication of high-performance optoelectronic devices. However, the growth of organic molecules into 2DOMCs remains a challenge because of the difficulties in controlling their self-assembly with a preferential orientation in solution-process crystallization. Herein, fullerene is chosen as a model molecule to develop a supramolecular gel crystallization approach to grow large-area 2DOMCs by controlling the perfect arrangement on the {220} crystal plane with the assistance of a gelated solvent. In this case, the gel networks provide tuneable confined spaces to control the crystallization kinetics toward the growth of dominant crystal faces by their inhibiting motions of solvent or solute molecules to enable the growth of perfect crystals at appropriate nucleation rates. As a result, a large-area fullerene 2DOMC is produced successfully and its corresponding device on a flexible substrate exhibits excellent bendable properties and ultra-high weak light detection ability (2.9 × 10¹¹ Jones) at a 10 V bias upon irradiation with 450 nm incident light. Moreover, its photoelectric properties remain unchanged after 200 cycles of bending at angles of 45, 90, and 180°. These results can be extended to the growth of other 2DOMCs for potentially fabricating advanced organic (opto)electronics.

Structural and electronic properties of C60 fullerene network self-assembled on metal-covered semiconductor surfaces

Using first-principles density functional theory calculations, we made an accurate structural characterization of the C₆₀ superstructures self-assembled on the Tl-adsorbed Si(111) and Ge(111) surfaces, which finds a good agreement with the recent scanning tunneling microscopy observations. Our band structure calculations revealed the semi-metallic character of the C₆₀/Tl/Si(111) system, while the C₆₀/Tl/Ge(111) system was found to show up the pronounced metallic character due to the cascade of the flat bands lying in the vicinity of the Fermi level. The latter is a fingerprint for strong correlation effects in the C₆₀/Tl/Ge(111) system, which makes it a promising object for studying electrical transport phenomena and opens the prospects for its application in the molecular-based electronic devices. We elucidated the details of the molecule-substrate and intermolecular interactions and discussed the character of a charge transfer in both systems.

Tailoring structural features and functions of fullerene rod crystals by a ferrocene-modified fullerene derivative

Effective functional intercalation and facile structural manipulation of fullerene crystals could be achieved by ferrocene-modified fullerene based on the liquid–liquid interfacial precipitation process.