Conductivity measurements of ultrahigh vacuum-sublimed (MPcF)n thin films (M=Al, Ga; Pc = phthalocyanine) were performed under ultrahigh vacuum and well-defined gas conditions. The intrinsic dark conductivity of as-prepared (GaPcF)n thin films is remarkably high (4 × 10−6 S/cm at 300 K) if compared to pressed pellets (3 × 10−6 S/cm at 300 K). After heating to 485 K, the conductivity decreases to 2.4 × 10−6 S/cm. This is the result of changes in the geometric structure observed in scanning electron microscopy. In contrast to (GaPcF)nm, a very low dark conductivity (< 10−9 S/cm at 300 K) is observed for (AlPcF)n. Light illumination in the visible range and exposure to dry oxygen have only a small influence on the conductivity, whereas exposure to ambient air and to water in a nitrogen atmosphere increases the conductivity of (AlPcF)n remarkably (6 × 10−2 S/cm at 300 K for pH2O = 0.2 mbar).
https://www.sciencedirect.com/science/article/abs/pii/037967799391208J#!