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

Characteristics of transformer, Q. Characteristics of Transformer? The ...

Q. Characteristics of Transformer? The characteristics of most interest to power engineers are voltage regulation and ef?ciency. The voltage regulation of a transformer is a me

Software, Write a computer program to implement the finite difference metho...

Write a computer program to implement the finite difference method. The program can be in any computer language that is available within the school. Set up the code to find the pot

Discuss the control words of ic8259, Discuss the control words (ICWS) of IC...

Discuss the control words (ICWS) of IC8259. The Intel 8259 is a single chip programmable interrupt controller. It is compatible with 8086, 8088 and 8085 microprocessor. It is a

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

Explain the terms dielectric constant and dielectric loss, Explain the term...

Explain the terms dielectric constant and dielectric loss. Dielectric Constant or Permittivity: all insulating materials possess an electrical capacitance. The capacitance of

Transformer, residual voltage in potential transformer

residual voltage in potential transformer

Demodulators for FM, Demodulators for FM Figure  shows a block diagram ...

Demodulators for FM Figure  shows a block diagram of a general FM demodulator, which is implemented by generating an AM signal whose amplitude is proportional to the instantane

Name the materials used in case of bimetals, Name the materials used in cas...

Name the materials used in case of Bimetals and give reasons. Bimetals : Alloy of nickel and iron along with low value of coefficient of thermal expansion are utilized as

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