Quantum Dots

Simon Fafard

The techniques used to manufacture computer chips have created a wealth of optoelectronic devices with remarkable features. These heterostructures (sandwiches created by alternating layers of two materials with different conductive properties) owe their special properties to structures which reduce the movement of electrons.
For example, laser diodes used to such great advantage in the telecommunication industry, were made possible by confining carriers, or electrons, within quantum wells. By further limiting the carriers, researchers hope to increase the efficiency and thermal stability of diode lasers, while reducing threshold currents. Dimension control, smoothness and uniformity of that quantum dots that form on the semiconducting layers are key elements of this research. By extending dimensional control to the second and third axes, we can exploit the potential benefits of wire and dot structures, potentially creating a new type of laser for use in optical computing, consumer products and telecommunications…