Determination of the effective Hall factor in p-type semiconductors

The comparison of free hole concentrations in p-type semiconductors obtained by Raman and by Hall measurements gives the possibility of determining an effective Hall factor depending on temperature and hole concentration. This will be shown for GaAs, GaP and InP in the temperature range from 77 K to 300 K. In the case of GaAs the experimentally obtained Hall factor is compared with a theoretical one, calculated from different scattering mechanisms within a two-band model. For the evaluation of Raman measurements a generalization of the Drude theory including interband transitions is used. Theoretical Hall factors and the comparison of calculated Hall mobilities with experimental ones are given. Possible sources of errors in the theory and in the evaluation of the experimental results are discussed.