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

Explain the properties of high resistive materials, Explain the properties ...

Explain the properties of high resistivity materials. High resistivity materials: The conducting materials containing resistivity from 10 -6 to 10 -3 ohm-m come under such

What is i/o mapping, What is I/O mapping? The assignment of addresses t...

What is I/O mapping? The assignment of addresses to various I/O devices in the memory chip is known as I/O mapping.

Induced voltage and inductance, Experiments conducted by Faraday and others...

Experiments conducted by Faraday and others using current carrying coils resulted in 'The Laws of Electromagnetic Induction' which state: 1)  'If the magnetic flux threading throu

Find current-equivalent resistor reductions for the network, Q. Find the cu...

Q. Find the currents I x using current division and equivalent resistor reductions for the networks given in Figure.

Express the waveform of the staircase type, Q. Express the waveform of the ...

Q. Express the waveform of the staircase type shown in Figure as a sum of step functions.

Explain common collector configuration, Q. Explain common collector configu...

Q. Explain common collector configuration? It is called the common-collector configuration because (ignoring the power supply battery) both the signal source and the load share

High voltage distribution system or hvds, High Voltage Distribution System ...

High Voltage Distribution System or HVDS Adoption of HVDS (High Voltage Distribution System) through converting existing LVDS to HVDS reduces the technical losses appreciably.

3 phase 4 wire meters, 3 Phase 4 Wire Meters 3-phase 4 wire meters (10...

3 Phase 4 Wire Meters 3-phase 4 wire meters (10/20, 20/50 A) are used for agricultural and industrial consumers. For loads up to 50 A, the meters are directly linked to the su

Interpoles and compensating windings, Interpoles and Compensating Windings:...

Interpoles and Compensating Windings: The most generally used method for aiding commutation is by providing the machine with inter poles, also known as commutating poles, or si

What do you mean by time consistent busy hour, Q. What do you mean by Time ...

Q. What do you mean by Time consistent Busy Hour? (i) Busy Hour (ii) Peak Busy Hour (iv) Time consistent Busy Hour  (v) Traffic intensity Ans: (i)  Busy Hour: C

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