Tutorial 4 (No Grade) : 18th April, 2012 DK6 8-9 am

In this week's tutorial (Hall Effects), I covered the calculation of electron concentration for an n-type material. Note that this is an adaptation from the textbook that I borrowed from the library entitled An Introduction to Semiconductor Devices by Donald Neamen pp. 162-164. For this type of problem, we can go to Lorentz force equation to get the equilibrium expression for the Hall electric field that can be related to the magnetic field applied.

Using Ohm's law, we can then calculate the mobility of the electrons.

I also did cover briefly, the effects of practical measurement of the Hall effects (see problem 3.21 Streetman's) which can be related to the conductivity or resistivity, perpendicular to the direction of the Hall voltage. Hence, by alternating the direction of the B fields, we can take the average measured voltage as the Hall voltage. The calculation of the concentration and mobility under these circumstances can be seen in Problem 3.20 Streetman's.