Semiconductors do not fall into either the conductor or non-conductor categories. Instead they fall in between. A substance, as silicon or germanium, with electrical conductivity intermediate between that of an insulator and a conductor. They can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide. Carbon, silicon and germanium (germanium, like silicon, is also a semiconductor) have a unique property in their electron structure -- each has four electrons in their outer shells. They are used extensively in electronic circuits. As its name implies, a semiconductor is a material that conducts current, but only partly. The materials that are neither conductor nor insulator with energy gap of about 1 eV (electron volt) are called semiconductors. They are in everything from your cell phone to rockets. Semiconductors are the middle ground between conductors and insulators and are made from silicon that is doped from different impurities to make it a suitable semiconductor. ON Semiconductor offers a comprehensive portfolio of innovative energy efficient power and signal management, logic, discrete, and custom semiconductor . Neither a conductor nor an insulator, N- and p-type semiconductors, Transistor: a device for amplifying electric current, TA widely known semiconductor is silicon.