Extreme Conductance Suppression in Molecular Siloxanes

作者：Li Haixing; Garner Marc H; Su Timothy A; Jensen Anders; Inkpen Michael S; Steigerwald Michael L^*; Venkataraman Latha^*; Solomon Gemma C^*; Nuckolls Colin^*

来源：Journal of the American Chemical Society, 2017, 139(30): 10212-10215.

DOI：10.1021/jacs.7b05599

Single-molecule conductance studies have traditionally focused on creating highly conducting molecular wires. However, progress in nanoscale electronics demands insulators just as it needs conductors. Here we describe the single-molecule length-dependent conductance properties of the classic silicon dioxide insulator. We synthesize molecular wires consisting of Si-O repeat units and measure their conductance through the scanning tunneling microscope-based break-junction method. These molecules yield conductance lower than alkanes of the same length and the largest length dependent conductance decay of any molecular systems measured to date. We calculate single-molecule junction transmission and the complex band structure of the infinite 1D material for siloxane, in comparison with silane and alkane, and show that the large conductance decay is intrinsic to the nature of the Si-O bond. This work highlights the potential for siloxanes to function as molecular insulators in electronics.

• 出版日期2017-8-2