Electronic structure-transport property relationships of polyferrocenylene, polyferrocenylacetylene, and polyferrocenylsilane

Combining nonequilibrium Greens function technique with density functional theory, the electronic structure-transport property relationships of polyferrocenylene, polyferrocenylacetylene, and polyferrocenylsilane were comparatively studied. We have found that the bridge group between two adjacent ferrocene units plays an important role in tuning their conductivity. The conductivity follows the sequence polyferrocenylene, polyferrocenylacetylene, and polyferrocenylsilane, in agreement with the experimental observation. The sequence cannot be interpreted by different band gaps; electronic structure factors such as Fe-Fe, Fe-cyclopentadienyl, and cyclopentadienyl-bridge group interactions, which influence the conductivity, are identified.