Manifestation of microcrystalline structure in transport properties of p‐quinquophenyl films

Abstract

The electrical conductivity measurements of the p-quinquephenyl films possessing microcrystallite structure are done at temperature between 10 K -300 K. The investigated film thickness varies within 0.2 -2.5 µm. The measurements were performed with Al(Au) electrodes for the films deposited by spin coating in argon atmosphere on glass substrates. The molecular dynamics simulations as well as quantum chemical calculations have shown that three different mechanisms contribute to the observed electrical feature, which are: the conductivity originated from proper crystalline states; this of the amorphous-like inter-grain region and the one created in the grain boarder interfaces. Comparing the experimental data and theoretically calculated dependencies, we have shown that the main contribution to the observed DC conductivity of this material results from the interfaces located at the borders of polycrystalline grains, although they possess a relatively low part of the total film volume.