Template guided self-assembling two-dimensional array of Au@SiO ₂ core-shell nanoparticles for room-temperature single electron transistors

The composite nanoparticles of a gold core capped by a SiO ₂ shell with well-controlled thickness have been synthesized and fabricated into two-dimensional array on silicon surface by a simple self-assembly method combined with an AFM nanolithography technique. Current-voltage measurements of the Au@SiO ₂ composite nanoparticles (shell thickness of 6 nm) show a well-pronounced Coulomb staircase with a period of 300 mV at room temperature, demonstrating single electron transistor behavior. The step width of the Coulomb staircase can be tuned by controlling the thickness of SiO ₂ shell. The tunable single electron tunneling properties make the 2D array of Au@SiO ₂ composite nanoparticles an ideal candidate for planar single electron transistor devices.