
Silicon is a semiconductor material used in quantum devices, wave detection, and crystal structures due to its electronic properties.Silicon (Si) is a metalloid, i.e., an element with properties intermediate between metals and nonmetals. Its atoms are arranged in a diamond-like lattice. It is the second most abundant element in the Earth's crust, found in quartz and silicates. A bandgap of 1.1 eV makes it a classic semiconductor: doping with phosphorus creates free electrons (n-type), and with boron—holes (p-type). The contact of p- and n-regions forms a p–n junction, the basis of diodes, transistors and solar cells.
Jöns Jacob Berzelius isolated amorphous silicon in 1824, and Henri Sainte-Claire Deville obtained crystalline silicon in 1854. The first point-contact transistor (1947) worked on germanium, but silicon quickly replaced it. In 1954, Morris Tanenbaum created the first silicon transistor at Bell Labs. Leo Esaki contributed to the understanding of junctions by investigating quantum tunneling and inventing the tunnel diode. Since then, miniaturization has progressed exponentially, approaching physical limits.
When n- and p-regions come into contact, a depletion region arises, creating a potential barrier. Under forward bias, the current increases exponentially; under reverse bias, it is blocked. This rectifying property is described by the diode equation. In metal-oxide-semiconductor field-effect transistors (MOSFETs), the voltage on the gate controls the conductivity of the channel. Operation is based on electrostatics, the Poisson equation, and carrier statistics (Fermi–Dirac distribution). In solar cells, the p–n junction separates photogenerated electron-hole pairs, generating an electric current.
Microchips in every phone and laptop; solar panels on roofs; glass and concrete around us.
The whole Silicon Valley is named after this element. The first silicon transistor was made in 1954, and since then the number of transistors on a chip has been doubling approximately every two years (Moore's law).


















