Krogy
Oct22-10, 04:52 PM
1. The problem statement, all variables and given/known data
Hall measurements are made on a p-type semiconductor bar (X) μm wide and (Y) μm thick. The Hall contacts A and B are displaced (Z) μm with respect to each other in the direction of current flow of (I) mA. The voltage between A and B with a magnetic field of 10 kG (1kG = 10^-5 Wb/cm2) pointing out of the plane of the sample is 3.2 mV. When the magnetic field direction is reversed the voltage changes to -2.8 mV. What is the hole concentration and mobility?
2. Relevant equations
w*Ey =[Ix*Bz]/[q*p*t] (p-type)
p =[Ix*Bz]/[w*Ey*q*t]
3. The attempt at a solution
What is killing me here is the magnetic field reversal. How does reversing the magnetic field allow us to get the true hall voltage? I don't understand this concept, shouldn't the hall voltage just be opposite when reverse. Doesn't the holes and electrons just switch polarity?
Hall measurements are made on a p-type semiconductor bar (X) μm wide and (Y) μm thick. The Hall contacts A and B are displaced (Z) μm with respect to each other in the direction of current flow of (I) mA. The voltage between A and B with a magnetic field of 10 kG (1kG = 10^-5 Wb/cm2) pointing out of the plane of the sample is 3.2 mV. When the magnetic field direction is reversed the voltage changes to -2.8 mV. What is the hole concentration and mobility?
2. Relevant equations
w*Ey =[Ix*Bz]/[q*p*t] (p-type)
p =[Ix*Bz]/[w*Ey*q*t]
3. The attempt at a solution
What is killing me here is the magnetic field reversal. How does reversing the magnetic field allow us to get the true hall voltage? I don't understand this concept, shouldn't the hall voltage just be opposite when reverse. Doesn't the holes and electrons just switch polarity?