Structures and charge transfer in metal-doped aromatic hydrocarbons

Organic based compounds were suggested as candidates for high temperature or room temperature superconductors since the electrons can interact with much higher excitation energy than the phonon energy in these materials. Recently, the discovery of superconductivity in aromatic hydrocarbons seemingly supports the above idea suggested by Little and Ginzburg. Chen et al reported that the Tc exceeds 120 K in K-doped p-terphenyl. This result clearly shows that organic compounds are potential room-temperature superconductors. However, the structural characteristics of metal-doped aromatic hydrocarbons and the charge transfer from metal to organic molecule have always been puzzled. Here we report these research results by employing the first-principles calculations. In this work, we will present the atomic positions in metal (K, Al, Ga, and In)-doped aromatic hydrocarbons and the distribution and the number of transferred charge, as well analyze the relation between them and electronic structures. The results is meaningful to understand this superconductivity in this kind of materials.