Electrons and holes in semi-counductor, Physics

Electrons and holes in semi-counductor

Metals have free electrons available in conduction band for conduction of electric current. As the valence band overlaps the conduction band and no forbidden energy gap exists in the conductor, small electric field is sufficient to move an electron into higher state without creation of hole. The flow of electrons constitute electric current.

Hence only electrons are charge carriers in metals like aluminium, copper, sliver etc.

In semiconductors, the forbidden energy gap is small. At room temperature, the electrons from valence band jump into conduction band creating a hole in valence band. When the semiconductor is connected to terminals of the battery, electrons move towards positive terminal and holes move towards negative terminal.

In the applied electric field, the electron occupies the hole by moving towards positive terminal and a new hole is created in the place of electron moved. This hole acts as a positive charge carrier, while electron acts as a negative charge carrier. Both these electron and hole currents constitute the total current.

                 I = Ielectrons + Ihole

Posted Date: 8/29/2012 1:37:22 AM | Location : United States







Related Discussions:- Electrons and holes in semi-counductor, Assignment Help, Ask Question on Electrons and holes in semi-counductor, Get Answer, Expert's Help, Electrons and holes in semi-counductor Discussions

Write discussion on Electrons and holes in semi-counductor
Your posts are moderated
Related Questions
Explain about the double-crucible method. Low loss fibers are mostly manufactured by using double crucible and vapour phase deposition method. The double-crucible method is

the equivalent capacitors of two capacitors 1.87microfarad when connected in series 8mf when connected in parrallel. find the individual capacitances

project on logic gates

Give the theory of plane diffraction grating for normal incidence.

What are the safety terms to be inspected on Rotary Junction Box? Ans: Safety terms to be checked on rotary junction box are full tightness of all terminal connections, main

Can anyone give me a clear picture of GRAVITY?How does it works and and where does it pulls everthing?

does sodium sulfate contain both ionic and covalent bonds

how can sensitivity curve b measured?

A student sits on a stool holding a 5.0-kg dumbbell in both hands. He extends his arms such that each dumbbell is 0.60 m from the axis of rotation. The student's moment of

If a particle in periodic motion moves back and forth (or to and fro) over the same path, then its motion it is called as vibratory or oscillatory. The examples of vibratory or osc