Monolayer Crystal Structure of the Organic Semiconductor 7-Decyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophene

The monolayer crystal phase structure of the organic semiconductor 7-decyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophene was theoretically investigated. On the basis of a transition model from the bilayer crystal structure obtained by X-ray diffraction to possible monolayer crystal structures, two model structures for the monolayer crystal, i.e., antiparallel and core-chain nanosegregated structures, were proposed. The carrier mobilities of these two monolayer crystal models were compared through theoretical calculations to obtain insight into the probable monolayer crystal structure model. The results show that the antiparallel monolayer crystal structure model is more probable than the nanosegregated model.