Programable molecular orbital states of C₆₀ from integrated circuits

The authors have reported experimental demonstration of four C60 programable molecular orbital states, C600, C60 1-, C60 2-, and C60 3-, through a charge-based nonvolatile memory cell. Owing to the monodisperse nature and molecular size of C60, very sharp Coulomb staircase is observed at room temperature. A physical model based on the molecular orbit structure, the charging energy solved by an electrostatic method, and the Fermi-level pinning theory yield good quantitative agreement with experiments. These not only lead to better understanding of the C60 molecular orbital structure and corresponding chemical redox levels, but also potentially pave the way for realizing reliable multilevel molecular memories.