Fermi dirac level, Electrical Engineering

Assignment Help:

Fermi Dirac level:

Sol. The Fermi level is simply a reference energy level. It is the energy level at which the probability of finding an electron n energy unit above it in the conduction band is equal to the probability of finding a hole n energy units below it in the valence band. Very simply, it can be considered to the average energy level of the electrons, as illustrated in fig. (a). For simplification let us assume that (i) widths of energy bands are  small in comparison to forbidden energy gap between them (ii) all levels in a band have the same energy, bandwidths being assumed to be small (iii) energies of all levels in valence band are E0, as shown in fig. (a) and (iv) energies of all levels in conduction band are EG. Let the zero energy reference level be taken arbitrarily at the top of the valence band, as shown in fig. (b). Now number of electrons in conduction band, where P represents the probability of an electron having energy EG. Its value may be determined from Fermi Dirac probability distribution function given as where P (E) is the probability of finding an electron having any particular value of energy E.


Related Discussions:- Fermi dirac level

Electron, Electron congratulations

Electron congratulations

Fundamental of metal casting, Fundamental of Metal Casting: Fundament...

Fundamental of Metal Casting: Fundamental of Metal Casting : Casting process is based on the property of a liquid to take up the shape of vessel containing it. Molten metal

Ac supply, its defination and mathematical expression if any

its defination and mathematical expression if any

What happen when negative bias applied to the gate of fet, Q. What happens ...

Q. What happens when a negative bias is applied to the gate of a FET? The result of applying a negative bias to the gate is to reach the saturation level at a lower level of V

Unconditional jump - jump instruction , Unconditional Jump JMP ( Uncon...

Unconditional Jump JMP ( Unconditional Jump ) Instruction: This  instruction is used to transfer  the execution to the  specified  memory  address unconditionally ( does not c

Explain how ccitt standards help in building the base band, Q. Discuss FDM ...

Q. Discuss FDM and illustrate how CCITT stndards help in building the base band? Ans: Frequency Division Multiplexing: It is the process of combining numerous informatio

Give applications of emitter follower, Q. Give applications of emitter foll...

Q. Give applications of emitter follower The emitter follower has the following principal applications: 1. To provide current amplification with no voltage gain 2. Impede

Circuit, Aplication of resonance in different divices

Aplication of resonance in different divices

A transistor has how many p-n junction, A transistor has (A) One p-n j...

A transistor has (A) One p-n junction.  (B) Two p-n junction. (C) Four p-n junction. (D) Five p-n junction. Ans: A transistor has two p-n junctions.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd