Engineering the morphologies and charge transport properties of newly synthesized dibenzochrysene-based small molecules by attaching various side groups

•Three triethylsilylethynyl-modified dibenzochrysene derivatives are described.•The derivatives have varied aromatic side-group of a different geometric size.•The morphological and electrical character depending on side-group are verified.•The small side-group promote the more-connected and higher ordered crystal.•The charge transport property is increased with decreasing size of the side-group.

The microstructure of small molecular semiconductors can be readily altered via side group-engineering although they have same conjugated core. Here, we study a variation of morphology and charge transport properties about derivatives of triethylsilylethynyl-modified dibenzochrysene (TES-DBC) depending on side group size. It was verified that the TES-DBC combined with smaller side group developed more favorable morphology to charge carrier transport. The TES-DBC derivative with thienyl (DTTES-DBC), the smallest side group, formed well-connected crystal domain with well-ordered molecular assemblies which facilitate fast charge carrier transport. In addition, a high (1,2,4-trichlorobenzene; TCB) and low (chlorobenzene; CB) boiling point was used as processing solvent to observe the effect of the film fabrication time on the molecular ordering according to side group size.

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