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Explain fermi dirac statistic and distribution for semiconductor?
Wiki User
∙ 14y ago
It would be difficult to understand the behavior of electrons without the Fermi Dirac statistics. Why in a metal, electrons can move freely to conduct the electric current and why their contribution in the same metal to the specific heat is negligible, as if their number become for an unknown reason, considerably reduced. We have here a problem of "statistical order" that can be explained only by using the Fermi Dirac statistics (the classical statical mechanics was unable to explain this phenomenon).
Wiki User
∙ 14y ago
Wiki User
∙ 14y agoThe conduction band in a piece of semiconductor consists of mainly available, empty energy levels. When calculating how many electrones will fil these levels and thus be counted in n, contributing to conductivity , we consider two factors : * How many energy levels are there within a given range of energy, in our case the conduction band . * How likely is that each level will be populated by an electron . The likelihood in the second item is given by a probabilty function called the Fermi-Dirac Distribution function . f(E) is the probability that a level with energy E will be occupied by an electron , and the expression is : f(E)= 1/[1 + exp( (E-EF)/(kBT) ) ] where kB is the Boltzmann's constant , 8.62x10-5[eV/K], and T is the Temperature indegrees Kelvin . EFis called the Fermi Energy or Fermi level , it is dermined as the energy point where the probability of occupancy of an electron is exactly 50% 0r 0.5 : f(E)= 1/[1 + exp( (E-EF)/(kBT) ) ] = f(E)= 1/[1 + exp( (EF-EF)/(kBT) ) ] = 1/ [1+ exp(0)] = 1/2
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Who has the greatest contribution in quantum mechanics among Heisenberg and Dirac and Schrodinger?
Heisenberg, Dirac and Schrodinger all made large combinations. Schrodinger is famous for his wave mechanics, Heisenberg for his matrix notation. Dirac realised that the theories of Heisenberg and Schrodinger were essentially the same. He also created the Dirac equation, an important step in the creation of a relativistic version of Quantum Mechanics.
What are the Laplace transform of unit doublet function?
The Dirac delta function.
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No it can not. About 75 yrs ago physicist Paul Dirac predicted there were tiny particles that were uni polar magnets. Because Dirac helped develop the theory of quantum mechanics scientists took his predictions very seriously and immediately tried to discover this uni polar particle. So far none has been found.
Why don't all theories become laws?
Scientific theories and laws technically are never true. They are models that scientists create in order to predict outcomes. Since nature has given us no essential axioms everything scientists have done is just a model. For example: When maxwell originally developed his theory he used a set of cogs and wheels to explain electromagnetism. He later realized these were not necessary and dropped them from his formulation. This changes the essence of his theory but both ways delivered the same predictions given a set of data points. Similarly, before Einstein, newtons laws were considered infallable however later we realized that newton's laws only work in certain realms. Even Einstein didn't have the whole story. Dirac later applied his relativistic theories to the quantum field. Currently dirac's theory has the largest realm of applicablity (although it is very difficult to use). However even dirac's theory cannot explain all realms. Therefore theories and laws, since they are not essential to nature and are just models and can be replaced.
Where can antimatter be found?
Antimatter is found in small amounts inside cosmic rays, and also extremely small amounts are created within stars. However, scientists believe that there could be galaxies made of antimatter, or even entire universes. Here on earth, we find antimatter being created as a result of a type of radioactive decay called beta plus decay. In that instance, a positron (an anti-electron) is ejected from an atomic nucleus as that nucleus transforms. Additionally, a gamma ray of sufficient energy passing close to an atomic nucleus may produce a positron-electron pair in what is called pair production. Those are the most common encounters we'll have with antimatter. We also see anti-protons being created and injected into accelerators like the Large Hadron Collider (LHC). In the LHC, protons and anti-protons are sped up as they circle the ring (in opposite directions) and then set on a collision course.
Explain fermi dirac statistic and distribution for metal?
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What is Fermi Dirac distribution function?
A function specifying the probability that a member of an assembly of independent fermions, such as electrons in a semiconductor or metal, will occupy a certain energy state when thermal equilibrium exists.
What is the birth name of Paul Dirac?
Paul Dirac's birth name is Paul Adrien Maurice Dirac.
When was Dirac Prize created?
Dirac Prize was created in 1921.
Who discovered antimatter?
The person who discovered antimatter was Paul Dirac. Paul Dirac.
What is Paul Dirac's birthday?
Paul Dirac was born on August 8, 1902.
When was Gabriel Andrew Dirac born?
Gabriel Andrew Dirac was born in 1925.
When did Gabriel Andrew Dirac die?
Gabriel Andrew Dirac died in 1984.
When was Paul Dirac born?
Paul Dirac died on October 20, 1984 at the age of 82.
What was the age when Paul dirac died?
Paul Dirac was 82 years old when he died.
What is Fermi-Dirac distribution function?
There are two different kinds of particles (electrons, protons, neutrons, atoms, molecules). Each such particle has a so called "spin" which is quantum mechanical value. Depending on spin particles behave differently in the same conditions and can be described using two different distributions. First one is Bose-Einstein distribution for particles with integer spin. Second on is Fermi-Dirac distribution for particles with spin n/2 (where n is an integer number which can take values starting from 1 and higher).
When did Paul Dirac die?
Paul Dirac died on October 20, 1984 at the age of 82.
