-1

It is not exactly a question its a kind of confusion ... Here my confusion starts... what is meant by Fermi energy level?? The only definition that i found was the energy level at which the probability of finding of electron is 50%..

First question is whether this definition applicable to all the materials or only for metals or only for semiconductors?? But in semi conductors the Fermi energy level is in mid of the valency band and the conduction band...

So my second question was in semi conductors whether the Fermi energy level is the maximum energy that the electron in that material is having or it is a particular energy that 50% of the electrons are having the energy more than that level ??

sorry if i am messing up the topic i am keeping all the confusions that are having in my mind in to words.

Last question was in if electron is in the highest energy level of the conduction band what does it mean ?? electron is having the energy only equal to the energy level????

Suneeldatta Kolipakula
  • 101

1 Answers1

0

That definition of the Fermi level is applicable to all materials. However, I believe you'll find it a lot clearer once you understand that the Fermi level is in fact the energy level at which the probability of an electron state being occupied is 50%.

In a semiconductor, the Fermi level is indeed in the forbidden band, however there are no available states in the forbidden band. Therefore, even though the probability of an electron state being occupied is 50%, there are no electrons present in the bandgap (0.5*0=0).

It is very incorrect to say that 50% of the electrons have energy above the Fermi level. While it is certainly possible if you have an incredibly skewed distribution of electron states, this is not true for most materials.

The area under the graph before the Fermi level is clearly much larger than the area after it.

I'm afraid I don't quite understand your last question.

Dr Coconut
  • 320