Influence of heteroatoms on the charge mobility of anthracene derivatives

The introduction of polarizable heteroatom, such as O, and S, attached peripheral side chains of conjugated moieties such as polyacenes has not been systematically investigated. To study such effects, and to explore semiconductors with both high charge mobility and luminescence properties, we present a comparative systematic study of heteroatom effects on the conduction of organic semiconductors in a representative series of new organic semiconductors based on the blue phenyl-anthracene molecule core. Elucidated by the single-crystal X-ray analysis, thin film XRD and AFM measurements, a correlation between the molecular structure variation, film ordering, and charge mobility has been established. Quantum chemistry calculations combined with the Marcus-Hush electron transfer theory interpret the transport parameters. The anisotropic transport properties of these compounds were suggested by the DFT predictions and the high hole mobility in BEPAnt and BOPAnt is contributed mainly by the parallel packing of these compounds with the highest ∥μ_h; these results are in good agreement with the experimental observations. Heteroatoms are demonstrated to influence the charge mobility dramatically. Our systematic investigation will provide valuable guidance for a judicious material design of semiconductors for OTFT applications.