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

Zener diode, Zener Diode A Zener diode is a sort of diode that allows ...

Zener Diode A Zener diode is a sort of diode that allows current not only in the forward direction such as a normal diode, but as well in the reverse direction if the voltage

Find the expression for the no-load speeds, Q For a three-phase, fully cont...

Q For a three-phase, fully controlled, recti?er-fed, separately excited dc motor, corresponding to ideal no-load operation, find the expression for the no-load speeds. Comment on w

Calculate the supply line current, A balanced star-connected load is connec...

A balanced star-connected load is connected across a three phase 450V 50 Hz AC supply. Each load element has an impedance of 5+j12 Ω. Calculate: (i)  The power factor of the

Advantages and disadvantages of aluminium, Discuss the advantages and disad...

Discuss the advantages and disadvantages of aluminium as compared to copper as a conductor of electricity. Advantages: Aluminium as a conductor of electricity as compared co

Find the per-phase impedance of the load, Q. A three-phase, three-wire 208-...

Q. A three-phase, three-wire 208-V system is connected to a balanced three-phase load. The line currents ¯ IA, ¯ IB, and ¯ IC are given to be in phase with the line-to-line voltage

Electrical Machine, i have an assignment due for submission within two days...

i have an assignment due for submission within two days. It is all about transformer measurement manually and numerical results using Matlab.Is there anyone can do the job?

Explain the operation of n-channel fet, Q. Explain the operation of N-chann...

Q. Explain the operation of N-channel FET? Transistor is a linear semiconductor device that controls current with the application of a lower-power electrical signal. Transistor

Can you draw robot configuration, a) Draw robot configuration. b) Explai...

a) Draw robot configuration. b) Explain the significance of end effectors. c) Define the terms (i) accuracy (ii) Repeatability (iii) Work volume (iv) Control Reso

Dc machines, a 400V 4-pole DC generator takes an armature current of 50A wh...

a 400V 4-pole DC generator takes an armature current of 50A when rotating at 626 rpm. the armature circuit resistance is 0,25ohms. determine the generated emf. DOC

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