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

Radiation intensity pattern of antennas, Q. Radiation intensity pattern of ...

Q. Radiation intensity pattern of Antennas? Antennas do not radiate power equally in all directions in space. The radiation intensity pattern describes the power intensity (whi

Representation of the control system, Question: (a) The forward path t...

Question: (a) The forward path transfer function of a unity feedback control system is given by: (i) Draw the labelled block diagram representation of the control system.

Matrix, create a matrix of 5x6. with identical columns and rows ranging fro...

create a matrix of 5x6. with identical columns and rows ranging from 200 to 1000 in equal increments

Full wave rectifiers, how to determine the peak inverse voltage across idea...

how to determine the peak inverse voltage across ideal diodes

Comperators, How to build a 6 bit comparator?

How to build a 6 bit comparator?

Circuit with inductive load, Circuit with inductive load  Electromagnet...

Circuit with inductive load  Electromagnetic induction When a conductor is moved across a magnetic field so as to cut by the lines of force (or flux, an electromotive force

Two converters - boost-buck (cuk) and flyback, Design two converters - boos...

Design two converters - boost-buck (Cuk) and flyback meeting the following criteria: Vin = 15 V ... 35 V    Vout = 25 V Output voltage ripple 1% peak to peak Switching frequen

Transformers, AC Operation of an iron core         ...

AC Operation of an iron core         Hence, if a wattmeter were used to measure the power delivered over a full period of the waveform (which will also b

Dual trace and dual beam cro, what is difference between dual trace and dua...

what is difference between dual trace and dual beam cro?

Intrinsic material, Int r insic Material A perfect semicon...

Int r insic Material A perfect semiconductor crystal with no impurities or lattice defects. No carriers at 0 K, since the valence band is completely full and t

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