Design and elaboration of organic molecules for high field-effect-mobility semiconductors

• Based upon the analysis of several molecular systems, the design strategy for molecules for high-mobility organic semiconductors are discussed.
• Correlation between molecular/packing structures and electronic structures in the solid state for representative high-mobility organic semiconductors are presented.
• Several different molecular factors that can be controlled are proposed for realizing high-mobility organic semiconductors.

In this article, we focus on several high-mobility organic semiconductors so far reported, such as acenes, heteroacenes, and rylene diimides, in order to extract molecular and supramolecular factors, including molecular size, manner of π-extension, heteroatom, molecular shape, and substituent, which would enhance our understanding of the design strategy for the synthesis of molecules for high field-effect-mobility semiconductors. After performing a detailed inspection of these organic semiconductors, we arrive at the conclusion that the construction of a two-dimensional (2D) electronic structure with large orbital overlaps in the solid state is the key. This can be realized by tuning these molecular factors; for example, the use of linearly π-extended systems with fused aromatic ring structures, heteroatom incorporation, and the use of suitable substituents for 2D packing, such as herringbone or 2D bricklayer packing.