Electronic device that operates on the basis of the electric, magnetic, or optical properties of a solid material, especially one that uses a solid crystal in which an orderly three-dimensional arrangement of atoms, ions, or molecules is repeated throughout the entire crystal. Synthetic crystals of elements such as silicon, gallium arsenide, and germanium are used in transistors, rectifiers, and integrated circuits. The first solid-state device was the "cat's whisker" (1906), in which a fine wire was moved across a solid crystal to detect a radio signal. See also semiconductor