title: Hydrostatic pressure effect on charge transport properties of phenacene organic semiconductors.
abstract: We investigate the charge transport properties of phenacene organic semiconductors including phenanthrene, chrysene and picene using density functional theory (DFT) calculations under hydrostatic pressure. Under compression, the crystal structures of the three materials are altered and thus, a decrease in the intermolecular distances gives changes in charge transport properties while the molecular structures remain stable. As a result of the applied pressure, the mobilities of these materials increase dramatically. Chrysene shows a transition from a p-type semiconductor to an ambipolar semiconductor at around 2.0 GPa. Interestingly, chrysene favors electron transport at above 3.0 GPa. On the other hand, both phenanthrene and picene exhibit hole transport characteristics under high pressure. Between 3.1 and 4.3 GPa, the picene crystal is found to transform from an anisotropic mobility to an isotropic mobility in the ab plane. We also found that, the bulk modulus representing the resistance of the material under pressure compression follows a linear relationship with molecular length.
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea. jhshim@postech.ac.kr.
authors.forename: Thao P
authors.initials: TP
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea. jhshim@postech.ac.kr and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 37673, Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Shim