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

Lc circuits, L=0.0053nH, C=15µF find the operating frequency of series LC c...

L=0.0053nH, C=15µF find the operating frequency of series LC circuit. What factors decides capacitance ..

#title.Electrical Machine., ) Design a suitable double –layer lap winding f...

) Design a suitable double –layer lap winding for a 6-pole dc armature with 18 slots

Show applications for dc machines, Q. Show Applications for DC Machines? ...

Q. Show Applications for DC Machines? Dc motors find wide applications in which control of speed, voltage, or current is essential. Shunt motors with constant speed are used fo

Explain the excess three codes - bcd to decimal conversion, Explain the Exc...

Explain the Excess three codes - BCD to Decimal Conversion The Excess-3 representation of a number is based on Binary Coded Decimal. It is formed by taking the number in Binary

Determine the magnetic force on the current element, Q. Given ¯B = (y ¯ax -...

Q. Given ¯B = (y ¯ax - x ¯ay )/(x 2 + y 2 ) T, determine the magnetic force on the current element Id ¯l = 5 × 0.001¯a A located at (3,4,2).

Find resistance of the armature circuit and field circuit, When delivering ...

When delivering rated load a 10-kW, 230-V self excited shunt generator has an armature-circuit voltage drop that is 6% of the terminal voltage and a shunt-field current equal to 4%

Determine the stresses set up in the cylinder and steel wire, A copper cyli...

A copper cylinder 40 cm diameter and 10 mm thick is nearly wound with a layer of 4mm diameter steel wire under a tensile stress of 80 Mpa. If the steam under a pressure of 5 Mpa is

Show voltage wave form of rlc series circuit, Q. The voltage wave form of F...

Q. The voltage wave form of Figure is applied to an RLC series circuit with R = 2, L = 2H, and C = 1 F. Obtain i(t) in the series circuit. (Note that the capacitor and inductor va

Explain the programming of 8254 microprocesser, Explain the programming of ...

Explain the programming of 8254 microprocesser. 8254 Programming: All counters are individually programmed through writing a control word, followed with the initial count.

Chemistry, what is the definition of laws of chemical combination ?

what is the definition of laws of chemical combination ?

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