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cartik
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Why does the Fermi level level drop with increase in temperature for a n type semiconductor.? What's the basic idea behind Fermi level?
How does it get affected by temprature?
How does it get affected by temprature?
cartik said:Why does the Fermi level level drop with increase in temperature for a n type semiconductor.? What's the basic idea behind Fermi level?
How does it get affected by temprature?
What's the basic idea behind Fermi level?
How does it get affected by temprature?
Why does the Fermi level level drop with increase in temperature for a n type semiconductor.?
Far before the semiconductor gets intrinsic, the Fermi level goes away from the conduction band as the number of electrons due to the dopant is nearly constant,
as is the equivalent density of states in the conduction band,
Ratch said:...You have not specified to which region you are referring...
...as the temperature rises from the freezout to the extrinsic region, the Fermi level moves toward the midpoint of the forbidden gap, and settles at room temperature Fermi level.
As the original post gives no exotic temperature and tells "N-type" I consider it's at normal temperature range, that is, when the dopant concentration determines primarily the carrier concentration. Extrinsic, yes.
And at this temperature range, there is no single Fermi level, precisely because the carrier concentration is in a first approximation constant.
The direct consequence of a constant electron concentration is that the Fermi level drops away from the conduction band when temperature increases. No intrinsic carrier density is needed for it.
The Fermi level in extrinsic semiconductors is the energy level at which there is a 50% probability of finding an electron. It represents the maximum energy that an electron in the material can have at 0 Kelvin, also known as the Fermi energy.
The Fermi level in extrinsic semiconductors is affected by doping, which is the process of intentionally adding impurities to the material. Doping introduces either excess electrons (n-type) or holes (p-type) into the material, which changes the number of available energy levels and shifts the Fermi level accordingly.
The Fermi level is important in semiconductors because it determines the electrical and optical properties of the material. It plays a crucial role in the band structure and can affect the conductivity and carrier concentration in the material.
As temperature increases, the Fermi level in extrinsic semiconductors shifts towards the conduction band. This is because as temperature rises, more electrons are excited to higher energy levels, increasing the probability of finding an electron at higher energy levels.
Yes, the Fermi level in extrinsic semiconductors can be controlled through the process of doping. By adding impurities to the material, the Fermi level can be shifted to a desired position, allowing for control over the electrical and optical properties of the material.