- #1
abomination5
- 5
- 0
Hi,
I have a questions regarding semiconductor-metal junctions that has been left unresolved. I hope that you can offer me an explanation.
I know that when a metal and n-doped semiconductor are in contact upward band bending occurs. This is because the Fermi levels in the two materials must be the same. This causes a diffusion force on the electrons. Eventually positive charge builds up near the junction which halts the diffusion current, thus establishing equilibrium.
My question is: what causes the shape of the potential? Why is it easier for electrons to flow in one direction than the other? The potential seems to undergo a steep drop on the metal side and a gradual drop on the semiconductor side. What causes this?
Thanks,
abomination5
I have a questions regarding semiconductor-metal junctions that has been left unresolved. I hope that you can offer me an explanation.
I know that when a metal and n-doped semiconductor are in contact upward band bending occurs. This is because the Fermi levels in the two materials must be the same. This causes a diffusion force on the electrons. Eventually positive charge builds up near the junction which halts the diffusion current, thus establishing equilibrium.
My question is: what causes the shape of the potential? Why is it easier for electrons to flow in one direction than the other? The potential seems to undergo a steep drop on the metal side and a gradual drop on the semiconductor side. What causes this?
Thanks,
abomination5