[21p-221A-1~6] 9.3 Nanoelectronics

▲ [21p-221A-3] Negative Differential Conductance on Au₂₅ Nanocluster Single-Electron Transistor

〇(D)JAEYEON KIM¹, Yoon Young Choi¹, Younsu Jung¹, Masanori Sakamoto², Toshiharu Teranishi², Yutaka Majima¹ (1.Tokyo Inst., 2.Kyoto Univ.)

Keywords:Single-electron transistor, Au25 nanocluster, Negative differential conductance

Currently, single-electron transistors (SETs) considered as one of the candidates of nextgeneration transistors, since SETs have advantages for low power consumption and multi-logic circuits. Here, we report single-electron transistors (SETs) based on the Au₂₅ cluster as Coulomb island toward a stable room temperature operation. Au₂₅ cluster consists of icosahedral Au₁₃ core as well as distinct bonding arrangement named “extend motif” (-S-Au-S-Au-S-) at the gold-thiolate interface [1], and the core diameter of Au₂₅ cluster is only 1.2 nm. We synthesized Au₂₅ nanocluster with 18 ligand molecules of 16 phenylethanethiol (PET) and 2 acetylthio-bipheny-thiol. For the Au₂₅ cluster SET fabrication, we have fabricated ultra-fine hemispheric electroless gold plated (H-ELGP) Pt-based nanogap electrodes. The Au₂₅ cluster has been chemisorbed between H-ELGP Pt-based nanogap electrodes from its solution. Clear gate voltage dependence of the I_d-V_d and dI_d/dV_d-V_d characteristics on single Au₂₅ cluster SET was obtained in Figure 1(a). Negative differential conductance (NDC) were observed as negative dI_d/dV_d peaks at positive V_d. Experimental stability diagrams as function of V_d and V_g with the color maps of dI_d/dV_d also clearly showed gate voltage dependence. NDR peak voltage move as lines parallel to the borderlines of the diamonds in the regions where the current is not blocked at positive V_d.