An Accurate Measurement of Carrier Concentration in an Inhomogeneous GaN Epitaxial Layer from Hall Measurements

An appropriate method for an accurate determination of carrier concentration from Hall measurements for samples having large inhomogeneities is presented. Parasitic contributions in such samples generally limit the capabilities of Hall experiments where even the measurement of carrier type in some samples becomes doubtful. Here, we eliminate the major parasitic contributions from the measured Hall voltage through a systematic averaging procedure over the current and magnetic field polarities. Further, the carrier concentration values are unambiguously determined from the magnetic field dependent Hall measurements, where the slope of true Hall voltage versus magnetic field plot provides realistic values of carrier concentrations.