Why semiconductor in Hall effect sensor?

[jaydnul]

Why is a slab of semiconductor used instead of just a basic resistor. The charge would be pushed to either side by the magnetic field in the same way, would it not?

 

[Drakkith]

That's a good question. I would imagine that resistors are not used because they inherently limit the flow of current, which is not what you want with a hall effect sensor since it relies on current to operate (not to mention the fact that resistors typically consume a lot of power compared to a semiconductor device). A quick search only tells me that semiconductor devices are used because they offer superior operation, but I haven't been able to find out why yet. I'll let you know if I find out anything else.

 

[Jeff Rosenbury]

Another possible reason (or perhaps part of the same reason) is that the charge carriers in P type semiconductors are holes (positive charges) instead of electrons. The Hall effect causes the electrons to migrate to one side of a conductor, and the holes to the other as I recall. Thus we could in theory use an N type for the electrons and a P type for the holes and maybe do some clever differential analysis. This is only speculation though.