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

Evaluate the available received power, (a) Some antennas have a physical ap...

(a) Some antennas have a physical aperture area A that can be identified and is related to the effective area A e by A e = ρ a A, where ρ a is known as the aperture efficiency.

Compute l per unit length for plate, Q. The inductance per unit length in H...

Q. The inductance per unit length in H/mfor parallel plate in?nitely long conductors in air is given by L = µ 0 d/w = 4π×10 -7 d/w, where d and w are inmeters.Compute L (per unit

Continuity equations, Continuity Equations These equations are fundame...

Continuity Equations These equations are fundamentally particle conservation equations: Electron continuity equation:  ∂n /∂t = (1/q) (∂j N / ∂X) + G N - R N Hole c

Wireless and communication, With a maximum excess delay of and a chip durat...

With a maximum excess delay of and a chip duration of , the multipath components fall in delay bins. This means that we experience leakage of energy between chips and the channel i

Working of crt, Q.   Explain working of CRT with suitable diagram discuss t...

Q.   Explain working of CRT with suitable diagram discuss the focusing arrangement. What is need of aquadag? OR Why are the operating voltages of a cathode ray tube arran

Determine the bits required for a d/a converter, Q. Determine the bits requ...

Q. Determine the bits required for a D/A converter to detect 1-V change when V ref = 15 V.

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