Why is a P-type semiconductor used instead of just a slab of resistive material? The moving charge would be moved by the magnetic field in the same way, causing a potential difference at the sides.

 

1) A slab of P type semiconductor is a slab of resistive material
2) Most materials will show some hall effect but you want significant one.
3) The material has to be in the form of a crystalline solid, as near as possible to a single crystal. Normal resistors do not come in this form. They are a film on the surface of a former, or a spiral of metal.

So it is easier and more reliable to prepare a slab of semiconductor to the required resistance to obtain suitable outputs.

 

1) A slab of P type semiconductor is a slab of resistive material
2) Most materials will show some hall effect but you want significant one.
3) The material has to be in the form of a crystalline solid, as near as possible to a single crystal. Normal resistors do not come in this form. They are a film on the surface of a former, or a spiral of metal.

So it is easier and more reliable to prepare a slab of semiconductor to the required resistance to obtain suitable outputs.

Why does the material have to by crystalline?

 

yeh, i want to know too - doesnt metal get as small?