Studies of molecular conductance with conducting probe AFM

Abstract

This thesis describes a research work in the field of molecular electronics. The molecular conductance was investigated by fabricating molecular junctions with the help of conducting probe atomic force microscope (AFM). Two types of molecules (saturated alkanethiols and oligo(phenylene ethynylene) (OPE)) were self-assembled into monolayers on atomically flat gold substrate. The probe of the conducting probe AFM was adopted as another electrode and has been connected with the molecules by applying a controlled force on the cantilever of the probe. Experimental results showed that, conjugated oligo(phenylene ethynylene) molecules have a more complicated self-assembly behaviors and a higher conductance than saturated alkanethiols. The charge transport process through OPE molecules can vary with the substituent functional groups of different electron induction effects.