CONDUCTOR,INSULATOR AND SEMICONDUCTOR

CONDUCTOR:-Electrical conductors are materials through which electrical current flows smoothly. Copper (Cu), aluminum (Al), zinc, gold (Ag) and silver (Ag) are the electrical conductors. A large amount of free electrons are found in the electrical conductive material. Each device powered by electrical energy is manufactured by conductive material. The resistivity of a conductor or metal is 10^–6..ohm-cm.the weak bond electrons behave like free electrons and these free electrons can move freely inside the substance but cannot leave the substance. these electrons responsible for electrical conduction.all the metals are conductors. Silver is very good conductor of electricity. cu,Al,coal,mercury,human body are also conductors of electricity.

INSULATOR:-The substance in which no of free electrons are negligible or the substance in which the current does not flow easily are call insulator or nonconductor.Electrons are very strongly bound in the atom of the conductive material, so they cannot move from one place to another. In this situation, no current can go through the substance.the resistivity of the insulator is 10¹³.the examples of the insulator are wood,wax,ebonite,sulfur etc.

SEMICONDUCTOR:-A semiconductor is a substance whose electrical properties lie between conductors and conductors. Germanium and silicon are the most popular examples of these substances. According to the energy band assumption, semiconductor materials at room temperature are those that:-the conduction and connective bands are partially filled and Those between which the Forbidden energy band is quite narrow is about one electron volt, for example, it is 0.75 electron volts for germanium and about 1.12 electron volts for silicon. There are two types of semiconductors 

1) Intrinsic semiconductor:-A semiconductor in its purest form is called an intrinsic semiconductor or we can say that semiconductor in which no impurities are found is called a intrinsic semiconductor. Thus pure germanium and silicon are natural semiconductors in their natural state.

2) Extrinsic semiconductor:-An extrinsic semiconductor is formed by adding a specific type of impurities to the intrinsic semiconductor. The method of adding impurities in a semiconductor is known as doping