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Metallic behaviour of carrier-polarized C$_{60}$ molecular layers: Experiment and Theory

Z. H. Lu·C. C. Lo·C. J. Huang·M. W. C. Dharma-wardana·Marek Z. Zgierski
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Abstract

Although C$_{60}$ is a molecular crystal with a bandgap E$_g$ of ~2.5 eV, we show that E$_g$ is strongly affected by injected charge. In sharp contrast to the Coulomb blockade typical of quantum dots, E$_g$ is {\it reduced} by the Coulomb effects. The conductance of a thin C$_{60}$ layer sandwiched between metal (Al, Ag, Au, Mg and Pt) contacts is investigated. Excellent Ohmic conductance is observed for Al electrodes protected with ultra-thin LiF layers. First-principles calculations, Hubbard models etc., show that the energy gap of C$_{60}$ is dramatically reduced when electrons hop from C$_{60}^-$ to C$_{60}$.

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Z. H. Lu, C. C. Lo, C. J. Huang, M. W. C. Dharma-wardana, Marek Z. Zgierski. 2004-11-02. Metallic behaviour of carrier-polarized C$_{60}$ molecular layers: Experiment and Theory. https://doi.org/10.1103/physrevb.72.155440

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