00:01
Hello students, in this question we have the energy band given as fermi energy ef is here.
00:11
This is the e0 and this is for metal case and for semiconductor this is e0 and there are the conduction band then there is fermi energy band then the ei band and then e valence band is there.
00:38
So this is a situation here so this is for semiconductor this is for metal two situations are there.
00:46
Now in an ideal metal semiconductor structure the energy band diagram would include conduction band valence band fermi energy and the energy level of the metal.
01:02
So the energy level of the semiconductor and also the vacuum level will also be there.
01:07
The conduction band of the semiconductor will be lower in energy compared to the conduction band of metal.
01:15
It will be lower in semiconductor compared to that of metal.
01:23
When you compare with metal the conduction band will be higher than that of semiconductor for metal case.
01:33
The valence band of the semiconductor will be higher in energy compared to the valence band of the metal.
01:40
So valence band will look like this in metal case.
01:44
The fermi energy will align with the energy level of the metal and the both cases in equilibrium that is evident and the energy levels of the metal and semiconductor will form a barrier at metal semiconductor interface.
01:59
So there will be a barrier at metal semiconductor interface.
02:04
Now this is the first part.
02:05
Now coming to the second part, the ideal metal semiconductor structure can be rectifying or non rectifying.
02:13
So it depends upon the barrier height of the metal semiconductor interface.
02:17
So let's this is a metal semiconductor interface.
02:21
This is the energy band of metal.
02:24
This is the e conduction band of metal and this is e conduction band of semiconductor.
02:32
Okay so there is a barrier to be crossed here for semiconductor to become conductor for the energy transference...