Switching Mechanisms in Molecular Switches

Book chapter, 2016

Molecular electronics aims at using tailor-built molecules as active device elements to achieve the desired electronic functionality. Molecular-based electronic switches appear to be the most promising candidates for compact memory arrays with low power consumption. In the past decade, detailed investigations have been performed on a great variety of molecular switches, including mechanically interlocked switches, conformational switches, and redox-active molecules. In this chapter, we will review basic switching mechanisms in molecular switches: thermal fluctuations, current-induced excitations, and quantum tunneling. We will demonstrate how the quantitative information allowing to judge between those different switching mechanisms can be extracted from the data measured on single-molecule devices. We will also discuss how the intrinsic switching properties may be affected when the molecule is bridged to electrodes, and how to distinguish whether the switching happens in molecular kernel or at the molecule-to-electrode interface.