Exploring Chemistry and Physics at the Nanoscale Using Mechanically Controlled Break Junctions

Abstract

The use of single molecules as circuit elements represents the ultimate in device miniaturization. The mechanically controlled break junction (MCBJ) technique is a commonly used method for the formation of metal-molecule-metal junctions. Using MCBJs, the electrical properties of single molecules can be investigated. In this thesis, an MCBJ experimental setup for the study of charge transport is described. Early investigations began with gold wire break junctions, eventually progressing to lithographically fabricated break junctions. In particular, the measurement electronics, LabVIEW programming and mechanical setup underwent significant revisions, leading to improvements in noise floor, sensitivity, and speed. The resulting setup is capable of measuring the charge transport properties of single molecule junctions accurately and at a high rate.