Presentation Information

[20p-D903-7]Two Consecutive Negative Differential Resistances in Single-Molecule Resonant Tunneling Device between Au/Pt Nanogap Electrodes

〇(D)Dongbao Yin1, Eiji Tsuchihata1, Haru Tanaka1, Ryosuke Nitta1, Seiichiro Izawa1, Ryo Shintani2, Yutaka Majima1 (1.Tokyo Tech, 2.Osaka Univ.)

Keywords:

single-molecule transistors,resonant tunneling transport,negative differential resistances

As one of the ultimate goals in nanoelectronics, constructing an electronic device using a single molecule enables the trend of ultra-fast resonant tunneling devices. Single-molecule electronic devices could use the exploration of charge transport through molecular orbitals, creating a variety of functional electrical circuits by individual molecules. Resonant tunneling transport at single-molecular orbital is as fast as 1 attosecond (10-18 s), which is much faster than the time by drift transport in nanoscale transistor.
Recently, we developed the fabrication method for heteroepitaxial spherical (HS)-Au/Pt nanogap electrodes, which consist of few-nm-scale gap separation prepared from heteroepitaxial Au growths by self-termination electroless gold plating (ELGP) on Pt surface, which exhibited the potential to be a novel platform for single-molecule electronic devices. Here, we demonstrate resonant tunneling transport in a single-molecule transistor consisting of HS-Au/Pt electrodes and a π-conjugated quinoidal-fused oligosilole, Si2×2 (3.5 nm in length), which has a rigid, planar π-conjugated system. The energy levels of molecular orbitals of Si2×2 enable resonant tunneling transport at a single-molecule level.
Drain current (Id)-drain voltage (Vd) characteristic of a Si2×2 single-molecule transistor is shown in Figure 1. The consecutive negative differential resistances (NDRs) are clearly observed at Vd = 1.2 and 1.5 V. These NDRs are attributed to the resonant tunneling transports through different two molecular orbitals of Si2×2. These two consecutive NDRs provide a new insight for single-molecular electronic devices and reveal a promising candidate of resonant tunneling transistors.