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

For the nor and inverter realizations, Q. For the NOR and inverter realizat...

Q. For the NOR and inverter realizations shown in Figure, find the truth table, the type of gate realized, and the expression for the logic output, in each case.

Explain fet amplifiers, Explain FET amplifiers? Just like the BJT ampli...

Explain FET amplifiers? Just like the BJT amplifiers, FET amplifiers are constructed in common-source (CS, analogous to CE), common-drain (CD, analogous to CC), and common-gate

RC coupled transistor amplifier., why we plot graph to find bandwidth is dr...

why we plot graph to find bandwidth is drawn b/w av/avmax v/s frequency not av v/s frequency?

Clipper, how to write kvl equation in series clipper circuit without any ba...

how to write kvl equation in series clipper circuit without any battery

Write a note on the application of emitter-follower, Q. Write a note on the...

Q. Write a note on the application of emitter-follower? An emitter follower can serve as a buffer for a voltage source. The voltage divider at left is a poor voltage source bec

Effective negative voltage, Effective negative voltage: Effect negati...

Effective negative voltage: Effect negative voltage of get, when depend upon Pitch of voltage: the level of that results in id =0 ma is defined by eggs =vp with vp

Calculate the active and reactive power, The variable resistor Z o in the ...

The variable resistor Z o in the circuit shown in Fig. 1  is adjusted until maximum average power is delivered to Zo. a)  Find the value of Z o b)  Calculate the maximum av

Transmission, what are the grond clearance for 220KV overhead transmission ...

what are the grond clearance for 220KV overhead transmission lines?

Determine the voltage drop, A 15 volts source is applied to a series 150 mH...

A 15 volts source is applied to a series 150 mH inductor and 169 pF capacitor. The resistance of the inductor plus the connecting wires is 1,6 W. Determine the voltage drop and

Describe transistor stability parameters, Q. Describe transistor stability ...

Q. Describe transistor stability parameters The two parameters are · The stability factor ,K · Stability measure,ß1 These parameters determine the transistor stability

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