- #1
neu
- 230
- 3
I understand the principle behind p and n type doping, but I don't understand how such a small amount, 1ppm, can cause such a massive change in the fermi energy.
as I understand it:
for the intrinsic case the number of electrons exactly matches the number of holes and the fermi energy is equal to the mid-gap energy.
When a very small amount of atoms are added which have an extra electron/hole then electrons/holes are added to system which adds extra levels (as in diagram).
But how can such a small addition of electrons/holes have such a large change in the fermi energy?
as I understand it:
for the intrinsic case the number of electrons exactly matches the number of holes and the fermi energy is equal to the mid-gap energy.
When a very small amount of atoms are added which have an extra electron/hole then electrons/holes are added to system which adds extra levels (as in diagram).
But how can such a small addition of electrons/holes have such a large change in the fermi energy?