Fermi level rise up with raisng up the temperature

In summary, in an Extrinsic semiconductor, the fermi level rises with increasing temperature when donors are present. This is because the electrons in the semiconductor tend to get trapped and move around within a "grid", rather than jumping into holes. The density of states in the semiconductor may also play a role in this phenomenon, with a higher density of states below the fermi level.
  • #1
montser
14
0
Hi,
Im just wondering, why the fermi level rise up with raisng up the temperature when donors are present in Extrinsic semiconductor?

thanx
 
Physics news on Phys.org
  • #2


montser said:
Hi,
Im just wondering, why the fermi level rise up with raisng up the temperature when donors are present in Extrinsic semiconductor?

thanx

If I understand your question correctly, perhaps this image is of interest.

Valence electrons in a semiconductor tend to get trapped into particular places and jump around within some type of "grid". The electrons can move around in their own little spot (and will do so with raising temperature) even though there may be a hole right beside them. Ie. they do not have enough energy to jump into the hole. Even if the electron has enough energy to jump into the hole beside it, the electron would leave a hole where the electron just jumped out of.
 
  • #3


montser said:
Hi,
Im just wondering, why the fermi level rise up with raisng up the temperature when donors are present in Extrinsic semiconductor?

thanx

What does the density of states (number of states per unit energy interval) look like in the Extrinsic semiconductor? Is there a higher density of states below the fermi level?
 
  • #4


thanx for yor hekp
 

FAQ: Fermi level rise up with raisng up the temperature

1. Why does the Fermi level rise with increasing temperature?

The Fermi level is the highest energy level in a material that is occupied by an electron at absolute zero temperature. As temperature increases, electrons gain thermal energy and can move to higher energy levels, causing the Fermi level to rise.

2. How does the Fermi level affect the electrical conductivity of a material?

The Fermi level determines the probability of finding an electron at a given energy level in a material. As the Fermi level rises with increasing temperature, more electrons can be found at higher energy levels, increasing the material's conductivity.

3. Does the Fermi level rise uniformly with temperature?

No, the Fermi level rise is not uniform across all materials. The amount and rate of rise depend on the specific material's band structure and the number of available energy states for electrons to occupy.

4. Can the Fermi level rise indefinitely with increasing temperature?

No, the Fermi level rise reaches a limit at high temperatures due to the Pauli exclusion principle. This principle states that two electrons cannot occupy the same energy level, so as the temperature increases and more electrons move to higher energy levels, some energy levels become unavailable for occupation.

5. How does the Fermi level rise with temperature impact the material's chemical reactivity?

The Fermi level rise can affect the chemical reactivity of a material by changing the availability of electrons for chemical bonding. As the Fermi level rises, more electrons become available for bonding, potentially altering the material's chemical properties.

Similar threads

I Fermi level in a nonuniformly doped semiconductor
Replies
3
Views
2K
I How does diffusion of high energy electrons shift band structure?
Replies
1
Views
2K
B Fermi Level in Metals: Exploring Effects on Conductivity
Replies
2
Views
5K
I Quasi Fermi level and intrinsic Fermi energy
Replies
2
Views
4K
Significance Of Fermi Level in Semiconductor
Replies
3
Views
9K
Donor Impurities and the Forbidden region
Replies
4
Views
2K
A Change in Fermi level with gradient of doping concentration
Replies
3
Views
3K
I Valence band and Fermi level difference?
Replies
4
Views
3K
Is it possible to shift the fermi level?
Replies
5
Views
4K
I Exploring PN Junction Loop: Fermi Level and Work Function
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top