Fermi dirac level, Electrical Engineering

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.

Posted Date: 2/8/2013 2:48:10 AM | Location : United States







Related Discussions:- Fermi dirac level, Assignment Help, Ask Question on Fermi dirac level, Get Answer, Expert's Help, Fermi dirac level Discussions

Write discussion on Fermi dirac level
Your posts are moderated
Related Questions
What is the size of ports in 8255? Port-A : 8-bits Port-CU : 4-bits Port-B : 8-bits Port-CL : 4-bits

Advantages of SDR 1. Easy to upgrade 2. Great flexibility. It can be dynamically updated with new software without any changes in hardware 3. Due to reduced number of har

Explain the ASSUME assembler directive with example ASSUME: It will be used to map the segment register names along with memory addresses. The Syntax is as g

Transistor Switching Circuit Design a) Sketchy a schematic diagram showing how a transistor can be used to control the operation of a relay b) Determine what is meant by ba

what is the significant of damping coficient

Q. Explain working of three-phase transformers? Transformation in three-phase systems can be accomplished in either of two ways: (1) connecting three identical single-phase tra

Q. Consider a current element I 1 d ¯ l 1 = 10 dz ¯ az kA located at (0,0,1) and another I 2 d ¯ l 2 = 5dx ¯ ax kA located at (0,1,0). Compute d ¯ F 21 and d ¯ F 12 experienc

Define Time and Shift Invariant? Time and shift invariant means that the system characteristics and shift do not change with time, i.e. the system output is independent of the

Q. An antenna with an effective noise temperature of 130 K couples through a waveguide that has a loss of 0.8 dB to a receiver. Find the effective noise temperature presented by th

1. Introduction : Theory:  Phase angle is defined as the number of degrees separating two sine waves of the same frequency. The Phase shift is defined as any change t