A cuboid of Ge has contacts over all of its 2mm × 1 mm ends and point contacts approximately half way along its 5 mm length, at the centre of the 5 mm × 1 mm faces. A magnetic field can be applied parallel to this face. A current of 5 mA is passed between the end contacts when a voltage of 310 mV is applied. This generates a voltage across the point contacts of 3.2 mV with no magnetic field and 8.0 mV when a field of 0.16 T is applied.

ii. Using the corrected Hall voltage find the carrier density in the Ge sample.

iii. Estimate the conductivity of the Ge.

iv. What is the mobility of the carriers?

ANSWERS:

ii) 1.04e21 m^-3

iii) 40.3 s/m

iv) 0.24 m^2/V*s