We present a computational study of the atomic morphology, structural order and charge transfer properties of radially -conjugated, closed-loop, highly strained chiral carbon nano-belts (CNB). Synthesis of nano-belts has recently...

Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer π∙∙∙π transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent π∙∙∙π interaction, direct construction of robust frameworks via noncovalent π∙∙∙π interaction is a difficult task. Toward this goal, we report a robust noncovalent π∙∙∙π interaction-stacked organic framework, namely πOF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent π∙∙∙π interactions. The elaborate porous structure, with a 1.69-nm supramaximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. πOF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range π∙∙∙π interaction, we demonstrate remarkable transport properties of πOF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position πOF in a direction toward porous and yet conductive materials for high-performance organic electronics.

An in-depth theoretical characterization of alternative structural architectures is reported for use in organic photovoltaic devices (OPV): a host-guest structure where a circular π -conjugated nanohoop electron donor encapsulates an electron acceptor fullerene, forming a circular donor/acceptor complex. The mesoscale morphology, pairwise charge transport at the donor or acceptor domains, and charge transfer reactions at the donor/acceptor interfaces are calculated. For a fundamental understanding, three prototype complexes are considered: C60@10-cycloparaphenylene (C60@[10]CPP), C70@11-cycloparaphenylene (C70@[11]CPP), C70@3-cycloparaphenyleneacetylene (C70@[3]CPPA). It is found that solid state packing is crucial for the interface morphology, charge transport, and the electronic performance of the materials. While contorted and stiff packing result in small structural disorder, electron-phonon coupling is reduced, charge mobility and charge transfer is limited by the complex transport network. In contrast, a regular packing arrangement suggests an efficient charge transport; however, it is limited by the large amount of disorder and relatively large electron-phonon coupling. Hole and electron mobilities in the order of 10 −3 to 0.1 cm 2 Vs −1 and 10 −5 to 10 −2 cm 2 Vs −1 have been extracted, respectively, and electron mobilities are found to be very susceptible to intermolecular arrangements. Power conversion efficiency of 10% under 1 sun illumination has been offered from time-domain drift diffusion model.