Structure and electronic properties of the nanopeapods—One dimensional C60O polymer encapsulated in single-walled carbon nanotubes

Delocalized exciton formation in C60 linear molecular aggregates

Organic semiconducting materials containing C60 molecules are efficient acceptors for planar perovskite solar cells. In this work, we theoretically investigate the optical and excitonic properties of C60 linear molecular aggregates (composed of 1 to 7 C60 molecules) via the real-time-propagation rt-TDDFT technique. In the case of a single C60 molecule, the photoabsorption peaks are dominated by localized molecular excitons. We furthermore demonstrate that, in the case of linear molecular aggregates, the photoabsorption peaks are contributed by localized molecular excitons, charge transfer excitons, and Wannier-like delocalized excitons. This result is different to the accepted theory that only localized molecular excitons or charge transfer excitons can be produced in organic semiconducting materials. This work provides additional insights into the exciton formation in C60 molecular aggregates and may help in the rational design of efficient solar cells.

Mechanical Properties of C3N Nanotubes from Molecular Dynamics Simulation Studies

Although the properties of carbon nanotubes (CNTs) are very well-known and are still extensively studied, a thorough understanding of other carbon-based nanomaterials such as C₃N nanotubes (C₃NNTs) is still missing. In this article, we used molecular dynamics simulation to investigate the effects of parameters such as chirality, diameter, number of walls, and temperature on the mechanical properties of C₃N nanotubes, C₃N nanobuds, and C₃NNTs with various kinds of defects. We also modeled and tested the corresponding CNTs to validate the results and understand how replacing one C atom of CNT by one N atom affects the properties. Our results demonstrate that the Young’s modulus of single-walled C₃NNTs (SWC₃NNTs) increased with diameter, irrespective of the chirality, and was higher in armchair SWC₃NNTs than in zigzag ones, unlike double-walled C₃NNTs. Besides, adding a second and then a third wall to SWC₃NNTs significantly improved their properties. In contrast, the properties of C₃N nanobuds produced by attaching an increasing number of C₆₀ fullerenes gradually decreased. Moreover, considering C₃NNTs with different types of defects revealed that two-atom vacancies resulted in the greatest reduction of all the properties studied, while Stone–Wales defects had the lowest effect on them.