The article discusses detailed procedures for performing Hall effect measurements on semiconductor samples. Key points include:
1. Sample preparation: Samples should be fabricated from thin semiconductor plates with four ohmic contacts. The average contact diameter and sample thickness should be much smaller than the distance between contacts to minimize measurement errors.
2. Equipment: Four-point probe resistivity measurement setup, digital multimeter, Wheatstone bridge, and semiconductor sample with four ohmic contacts are required.
3. Resistivity measurements: Eight voltage measurements are taken between different contact pairs. Resistances RA and RB are calculated and used to determine sample resistivity if the conducting layer thickness is known.
4. Hall measurements: A strong magnetic field parallel to the sample’s z-axis is applied. Hall voltage measurements are taken in both positive and negative field directions. Sheet carrier density (ns) and bulk carrier density (n) are calculated using specific equations.
5. Key equations: Sheet carrier density is calculated as 8e-8 * I * B / (q(C+D+E+F)) where I is current, B is magnetic field, q is charge, and C, D, E, F are voltage differences. Carrier density is then calculated as n = ns/d where d is the conducting layer thickness.
The article provides a comprehensive guide for conducting accurate Hall effect measurements on semiconductor samples, including detailed procedures, required equipment, and key equations for data analysis.
Keywords: Hall measurement, Resistivity measurements, Magnetic field
