Moletronics or the Molecular Electronics is the branch of Nanotechnology that forms the study and applications of molecular building blocks to create electronic devices. Molecular electronics combines interdisciplinary branches like physics, chemistry material science etc. Using the Moletronics methods, it is possible to create passive components such as resistors and active components like transistors.
Two related fields in Moletronics are used to create the electronic components. These are molecular materials for electronics which focus on bulk properties of the material and the molecular scale electronics, which is concerned with single molecule applications. In 1974, John Mc Ginness demonstrated the working of the Voltage controlled switch made through the Moletronics technology. This switch was made of DOPA melanin, a mixed polymer of Polyacetylene and Polyaniline. The switch showed metallic conductivity in the ON state.
The charge transfer complexes were identified as the highly conducting compounds. These compounds show electrical conductivity like metals. Salts like Tetrathiafulyalene have shown full electrical conductivity. Melanins are considered as the back bone of conductive polymers. Compounds such as Polyacetyle, Poly pyrrole, Polyaniline etc are the major conductive polymers. Studies have shown that the iodine doped polypyrrols have a resistance as low as 1 ohm.
Polymers are organic molecules composed of both carbon and hydrogen. Sometimes additional molecules such as nitrogen, chlorine, sulphur etc are also found. Most of these molecules are insulating when their length exceeds a few nanometers. Naturally occurring carbon is conducting. Graphite is a conducting material and is considered as a semi-metal, a category in between metals and semi-conductors. It has a layered structure, each sheet being one atom thick. Between each sheet, the interactions are weak enough to allow an easy manual cleavage.
How Moletronics work?
The Moletronics works in the Quantum realm of less than 100 nm distance. In the low bias voltage regime, the non-equilibrium nature of the molecular junction can be ignored, and the current-voltage characteristics of the device can be calculated using the equilibrium electronic structure of the system. Recent progress in Nanotechnology and Nanoscience has facilitated both experimental and theoretical study of molecular electronics. The development of the scanning tunneling microscope (STM) and the atomic force microscope (AFM) have helped to manipulate single-molecule in molecular electronics