How does a single slab of p/n-type semiconductor act under a voltage? Does it just have a series resistance? Does it have a defined voltage drop?

Also why is this used in a Hall Effect sensor instead of just a normal resistive or conductive material? The magnetic field would displace the moving charge in the same way, would it not?

Thanks a bunch!

 

The voltage is caused by charge displacement across the thin conductor ribbon from the magnetic field (similar in principle to the deflection in a CRT tube) so metallic conductors with normally low sensitivity can be used (mainly electron flow but with 'hole' flow in some metals) but semiconductors can also have current flow from 'holes' (electromagnetic forces in the exact opposite direction), the Hall voltage produced is proportional to the mobility of the charges (easily controlled in a semiconductor by modifying the crystal lattice structure by doping) and develop a positive Hall coefficient for current flow in p types.

It is clear that the Hall voltage is proportional to the current flowing through the ribbon, and the magnetic field-strength, and is inversely proportional to the number density of mobile charges in the ribbon, and the thickness of the ribbon. Thus, in order to construct a sensitive Hall probe (i.e., one which produces a large Hall voltage in the presence of a small magnetic field), we need to take a thin ribbon of some material which possesses relatively few mobile charges per unit volume (e.g., a semiconductor), and then run a large current through it.

http://farside.ph.utexas.edu/teaching/302l/lectures/node74.html

 

K, I understand. The less mobile charge carriers, the stronger the Hall voltage.

But what does a doped semiconductor act like under a normal voltage at its ends? Is it basically a resistor? Does the resistance change with the number of charge carriers?

 

K, I understand. The less mobile charge carriers, the stronger the Hall voltage.

But what does a doped semiconductor act like under a normal voltage at its ends? Is it basically a resistor? Does the resistance change with the number of charge carriers?

It's a lot more complex than just that but yes, it's basically a resistor but one that sensitive to doping density that changes the bulk mobility.
http://ecee.colorado.edu/~bart/book/mobility.htm#resistivity