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

Write discussion on Construction and working of analog type, Write discussi...

Write discussion on Construction and working of analog type storage oscilloscope

Multitasking - single processor many users many tasks , Multitasking -  Si...

Multitasking -  Single Processor Many Users Many  Tasks In multitasking or also  called  time sharing  systems  multi  user  more than  one users are sharing  one processor

Internal frequency compensation of operational amplifier, Q. Internal Frequ...

Q. Internal Frequency Compensation of operational amplifier? Some op amps, such as the 741, have internal RC networks which are intentionally designed to reduce gain at high fr

Commutation in dc machines, Currents induced in armature conductors of a d....

Currents induced in armature conductors of a d.c. generator are alternating. To make their flow unidirectional in the external circuit, we need a commutator. Moreover, these curren

What is capacitance, What is Capacitance -  Capacitance is explained to...

What is Capacitance -  Capacitance is explained to be the amount of charge Q stored in among the two plates for a potential difference or voltage V existing across the plates.

Dual beam, explane the special features of dual beam?

explane the special features of dual beam?

Calculate the induced voltage, Q. A four-pole, lap-wound armature has 144 s...

Q. A four-pole, lap-wound armature has 144 slots with two coil sides per slot, each coil having two turns. If the flux per pole is 20 mWb and the armature rotates at 720 r/min, cal

Chemical vapour deposition, Explain chemical vapour deposition method for t...

Explain chemical vapour deposition method for the preparation of nanomaterial and its properties

Explain the working of direct memory access controller, Explain the various...

Explain the various modes in which DMAC works. Working of Direct memory access controller: The modes of operation has demand mode, block mode, single mode and cascade mode.

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