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

Congestion, It is uneconomic to provide adequate equipment to carry all the...

It is uneconomic to provide adequate equipment to carry all the traffic which could possibly be offered to a telecommunication system. In a telephone exchange it's theoretically po

Describe the uses of GPS map, Describe the uses of GPS map This is far...

Describe the uses of GPS map This is far safer because a driver of a vehicle doesn't have to consult maps while driving. It also removes error (for example going the wrong way

Working out the function of a combination of gates, Working out the functio...

Working out the function of a combination of gates? Truth tables are able to be used to work out the function of a combination of gates. Inputs Outputs

How an electroscope charged without contacting charged body, An electroscop...

An electroscope charged WITHOUT contacting a charged body is charged by: a) Induction b) Conduction c) Convection d) Insulation Ans: An electroscope char

Find the source voltage, Q. A semiconductor diode with IS = 10µA and a 1-k...

Q. A semiconductor diode with IS = 10µA and a 1-k resistor in series is forward-biased with a voltage source to yield a current of 30mA. Find the source voltage if the diode I-V e

Give examples of natural insulating materials, Give four examples of natura...

Give four examples of natural insulating materials. Illustrations of the natural insulating materials are rubber, cotton, wood and mica.

Determine the shaft power output, Determine the shaft power output: A ...

Determine the shaft power output: A 6-pole, 50 Hz, 3-phase induction motor running on full load develops a useful torque of 180 Nm when the rotor emf frequency is 2 Hz. Determ

Induced emf, applications of dynamically induced emf

applications of dynamically induced emf

Calculate the pu voltage and line to line voltage, The one line diagram of ...

The one line diagram of a simple power system is shown below. The data of the system are given in the table below. (a) Draw the impedance diagram of the system and mark all impe

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