Scientific discoveries - Essay Example

Scientific Discoveries Introduction Diodes constitute an important and versatile component of the world of electronics, not much of which is clearto an outsider. It is comes in several sizes and forms and employed as essential components with particular reference to the semiconductor industry. The explosion in the field of electronics has led to the search for smaller, cheaper, faster, and more efficient diodes and this search has entered the nanoscale domain. (1). The Molecular Diode Constable and Somerville 2003, p.

239, define nanotechnology as “manipulation of matter on atomic and molecular scales”. (2). Molecular electronics face two types of challenges. The first challenge is building molecular structures that act as switches and the second challenge is combining these molecules into a complex circuit in order that they are able to perform a specific function. These two tasks demand reproducible organic molecular conductors and insulators. Polyphenylene based molecules besides carbon nanotubes have been considered as possible candidate molecules capable of these tasks (3).

In October 2009 a team of researchers led by bio-designer N. J. Tao reported success in the development of key electrical component of the diode on a phenomenally tiny molecular scale, namely the single-molecule diode. (4). Figure -1(4) Diodes constitute critical components for a wide range of applications that include power conversion equipment, radios, logic gates, photodetecters and light emitting devices. In all these applications diodes make up the components that permit current to flow in one direction, but not in the other direction in an electrical circuit.

To bring this specific function down to the level of a molecule, the molecule should be physically asymmetrical, where one end of the molecule has the capacity to form a covalent bond with the negatively charged anode terminal and the other end capable of bonding with the positively charged cathode terminal. A symmetrical molecule allows current to flow in both directions, which is similar to an ordinary resistor. On the other hand an asymmetrical molecule allows current to flow in only direction similar to a diode, which is the more important and difficult component to replicate.

With the size of a transistor in the field of electronics nearing a few ten nanometers or about twenty times larger than a molecule, the development of a molecular diode is exciting. (5). The Tao led research team studied conjugated molecules for the purpose of developing a molecular diode. In conjugated molecules the atoms are stuck together by alternating single and multiple bonds. These molecules demonstrate strong electrical conductivity and also possess asymmetrical ends that have the capacity for spontaneously forming covalent bonds with metal electrodes to form a closed circuit, making the ideal candidates for development as molecular diodes.

This exciting development allows examination of a single molecule through the application of a voltage, or a mechanical force, or an optical field, and measure current and the response. The behavior of single molecules is governed by the laws of quantum physics and this capability makes it possible to study the properties that are distinct from the properties in the behavior of conventional devices. (4).Conclusion The development of the molecular diode through the use of nanotechnology is an exciting advance, as it paves the way for smaller electronic devices, where diodes are employed and in addition stands out as an example of the benefits that can accrue from employing nanotechnology.

Works Cited1. Harth, Richard. “Small . smaller . smallest? ASU researchers create molecular diode”. 2009. 23 October 2009. .2. Constable, George & Somerville, Bob. A century of Innovation. Washington, D.C: Joseph Henry Press, 2003.3. Kumar, Jagadesh. M. “Molecular Diodes and Applications”. Recent Patents on Nanotechnology, 1.1 (2007): 51-57.4. Melville, Kate. “Nanotronics within reach with creation of molecule-sized diode”. 2009. 23 October 2009. .5. “Smallest Electronic Component: Researchers Create Molecular Diode”. 2009. ScienceDaily.

23 October 2009. .