Basic Electronics

The electronics devices such as diodes, transistors, field effect transistors, thyristors, integrated circuits etc. are made of special materials called "semiconductors". These materials are called semiconductors because their conductivity lies between that of a metal and insulator. The conductivity of semiconductors can be controlled since it depends on temperature and the temperature of semiconductors can be controlled easily. Therefore it is sometimes called as "part time" conductors whose conductivity can be controlled.

The conductivity of semiconductors increases with increase in temperature. The most popularly used semiconductor materials are Silicon and Germanium. Most electronic devices are fabricated by using semiconductor materials alongwith conductors and insulators.Silicon is the most common material used to build semiconductor devices.
• Si is the main ingredient of sand and it is estimated that a cubic mile of seawater
contains 15,000 tons of Si.
• Si is spun and grown into a crystalline structure and cut into wafers to make
electronic devices.
The semiconductor materials are used for specialized applications. The Gallium Arsenide (GaAa) and related compounds are used for high speed devices and optical devices.