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

Society in engineering, Cite a specific example in which the engineer must ...

Cite a specific example in which the engineer must provide maximum efficiency for a given cost

Write explanatory notes on 8284 clock generator, Write explanatory notes on...

Write explanatory notes on 8284 Clock generator. The 8284 is an ancillary element to the microprocessors. Without this clock generator, a few additional circuits are needed to

Calculate the dc voltage appearing across the brushes, The armature of a fo...

The armature of a four-pole dcmachine has a simplex lap wound commutator winding (which has the number of parallel paths equal to the number of poles) with 120 two-turn coils. If t

Describe what you understand by offset voltage, a. Describe what you unders...

a. Describe what you understand by 'offset voltage' and 'offset current' of op-amp.  Discuss with a neat circuit diagram the method used for minimizing offset voltage and offset cu

Introduction to electronics, Explain the difference between a microprocesso...

Explain the difference between a microprocessor and an embedded microcontroller

Explain the different instruction formats, Explain the different instructio...

Explain the different instruction formats with examples The instruction set is grouped into the following formats One byte instruction MOV C,A Two byte instruction

Drift current density and conductivity, Drift Current Density and Conductiv...

Drift Current Density and Conductivity: Consider a conductor of length / meters and cross sectional area a square meters, as shown in Fig. Let the number of free electrons ava

Explain mechanisms of propagation of radio communication, Explain mechanism...

Explain mechanisms of propagation of radio communication. Radio communication deals with electronic radiation of electromagnetic energy from one point to another through atmosp

Determine overall power factor of the combined load, Q. Two balanced, three...

Q. Two balanced, three-phase, wye-connected loads are in parallel across a balanced, three-phase supply. Load 1 draws 15 kVA at 0.8 power factor lagging, and load 2 draws 20 kVA at

High frequency induction heaters or magnetic fields, High Frequency Inducti...

High Frequency Induction Heaters or Magnetic Fields : If this type of equipment is in use, large currents may be induced in any nearby metallic object or circuit, which will in tu

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