Semi-conductors, Physics

 

Semiconductor is solid material whose electrical conductivity at room temperature lies between conductivity of a conductor and that of an insulator. At high temperatures its conductivity approaches that of a metal, and at low temperatures it acts as insulators. Every material can be classified as a conductor, an insulator, or a semiconductor. These three distinct classes of material arise from a difference in the structure of the allowed electron energy level. In particular every material possesses both valance and a conduction band for electrons and the energy difference between these two bands will determine how easily an electric current will pass through the material. In semiconductor there is a limited movement of electrons, depending upon the crystal structure of the material used. The substances firstly used for semiconductors were the elements Silicon, germanium and gray tin. It was establish that the incorporation of some impurities in them improves their conductive properties. The property either adds free electrons or creates in holes in the crystals structures of the host substances by attracting electrons. Thus there are two kinds of semiconductors: N-type (negative) in which the current carriers are negative and the P-type, in which the positively charged holes move and carry the current. The process of adding this impurity is called doping, the impurities themselves are called do pants. Certain chemical compounds, including Gallium Arsenide, Indium antimonite, and aluminium phosphate are semiconductors.

 

Posted Date: 7/7/2012 8:49:13 AM | Location : United States







Related Discussions:- Semi-conductors, Assignment Help, Ask Question on Semi-conductors, Get Answer, Expert's Help, Semi-conductors Discussions

Write discussion on Semi-conductors
Your posts are moderated
Related Questions
Q. A compound microscope consists of an objective lens of focal length 2.0cm and an eye piece of focal length 6.25cm separated by a distance of 15cm.How far from the objective sho

Determine the volume of bodily fluid A 60.0 kg runner expends 330 W of power while running a marathon (Fig. P11.28). Assuming that9.00% of the energy is delivered to the muscle

Formers used for winding coils are ceramic or glass, because they are stable. Copper wire with silver plating is used up to 50 M Hz. Lit wire produces lower RF resistance than soli

Q. Illustrate about Optical Memories? In 1983 one of the most successful consumer products of all times was introduced which is compact disk (CD) digital audio system. This CD

At what velocity a clock should move so that it seems slow by one minute in a day.

projectile down an inclined plane

what are characteristics of resistances

newtons 3 law

screw gauge mostly based on what theory

Explain Cement concrete Cement concrete is a mixture of cement, sand, pebbles or crushed rock and water, which where placed in the skeleton of forms and permitted to cure becom