A superlattice is a structure made up of alternating layers of different materials. These layers are typically measured in nanometers, and the typical superlattice is extremely small. These structures are used in creation of new forms of semiconductors that exhibit different properties than their included materials. As this technology enters the mainstream, it is believed it will allow scientists to create materials with vastly different properties without any changes in its appearance.
The structure is made by stacking layers of different materials on top of one another. These layers are very thin, thinner even than a human hair. By stacking such thin materials together, the properties of the individual materials blend together in unexpected ways. This combination of properties allows scientists to create substances that have properties that are rare or unknown among natural materials.
There are two common reasons for making a superlattice structure. The first is to increase the material's resistance to shearing effects. The process of making a superlattice increases the resistance to shearing far beyond the resistance possessed by any of the constituent materials. This resistance allows the material to maintain its structure under higher stresses than traditional materials.
The other common reason for the construction of a superlattice is to produce new varieties of semiconductors. These materials transmit electricity better than an insulator, but not as good as a conductor. They are used in nearly every form of modern electronics, often in the form of an integrated circuit or microchip. Current semiconductors are usually made of silicon, but superlattice semiconductors may be made of many different things.
Semiconducting superlattices have a handful of advantages over typical semiconductors. These manufactured materials can conduct electricity faster or slower than a typical silicon semiconductor, simply by altering the amounts of substances in the lattice. This will allow the custom construction of a semiconductor with very specific tolerances.
Another advantage involves keeping some properties of the latticed materials separate. By creating a layered conductor, it is possible to send currents of varying power across the semiconductor. In effect, each layer relays power at its natural speed. This will allow a single material to operate on two different frequencies at the same time, improving material response time.
Few manufactured goods are utilizing superlattices. Some companies are experimenting with batteries and light bulbs that use superlattice-based cathodes, but they are very rare. The research that is ongoing in the field will likely change that. Superlattice structures have many properties that, when added to common consumer goods, will increases their lifespan and reduce their power consumption.
By M. McGee