An efficient strategy for designing n-type organic semiconductor materials - Introducing a six-membered imide ring into aromatic diimides

The aromatic diimides are among the most promising and versatile candidates for organic optoelectronic materials due to their commercial availability, low cost, excellent optical and electric performance, such as naphthalene, anthracene and perylene diimides. But, so far, the problem is not clarified - is a five- or six-membered imide ring more helpful for n-type organic semiconductor materials? The work investigated in detail and compared various properties for molecules with a five-/six-membered imide ring from the following aspects: (1) molecular stability, reaction activity, geometries, frontier molecular orbitals as well as oxidation and reduction abilities at the single-molecule level; (2) the variation of transfer integrals at the various molecular stacking motifs; (3) the estimate of carrier mobility and its anisotropy for the actual molecule crystals. The results indicate that molecules with a six-membered imide ring should be more suitable for n-type organic semiconductor materials.