Semiconductors combine the process of conductors and insulators. Semiconductors made of different materials work well when they have four valence electrons in the outer orbit of the atom. The electrons are able to form a lattice. The lattice formed in silicon (most common semiconductor material) creates a silvery crystalline form. The lattice forms covalent bonds. A covalent bond is a chemical paring that shares its electrons between atoms. In the case of semiconductors they are located outside. The lattice is so perfectly created and uniform because, there are no free electrons to conduct electricity. This means silicon is an insulator, not a conductor.
A diode is used to manipulate the semiconductor material, in a process called doping. A diode allows a current to flow in a single direction. By “doping” a semiconductor material, an impurity is added to the material (silicon in this example). Doping creates two types of relationships a P-type (positive) and N-type (negative). The doping allows for extra valence electrons in the outside orbit of an atom. Instead of an even number, an odd number of electrons occur. This odd number allows for the two types of elements to bond. Alone P and N types are not very strong but once meshed together, they create a current when applied to a power source. Using the different types of relationships allows the silicon to become a conductor. The power source can be big as a battery or small as Nano technology allows. Once the power source and diodes create a junction, the current can flow throw a pathway and create energy.