Metal-Semiconductor Transition In Ultrathin Cobalt-Phthalocyanine Films Grown On Srtio3 Single Crystal Substrates

We have investigated the low temperature charge transport properties of ultrathin cobalt-phthalocyanine films grown on (100) SrTiO3 single crystal substrates. The temperature dependence of resistivity shows an anomalous behavior, i.e., a transition from semiconducting to metallic behavior at around 110 K. We demonstrated that metallic behavior in these films is triggered by compressive strains of the SrTiO3 substrate due to its cubic to tetragonal structural phase transition at 110 K. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704141]