Electronic properties of hybrid Cu2S/Ru semiconductor/metallic-cage nanoparticles

Hybrid inorganic nanoparticles, comprising a semiconducting Cu2S quantum-dot (QD) core encapsulated by a metallic Ru cage-like shell, and each of their individual components, are studied via scanning tunneling spectroscopy. Bare Cu2S QDs show nearly identical semiconducting-like I-V characteristics while the empty Ru cages exhibit single electron tunneling effects-the Coulomb blockade and staircase. Surprisingly, in some cases negative differential conductance features, with periodicity that correlates to the Coulomb staircase, were observed. The tunneling spectra measured on the hybrid QDs varies greatly along a single particle, manifesting synergetic electrical properties that originate from this unique semiconducting-metallic interface.