The conductivity mobility for the combined valence band can be expressed by
3 e* m3/2
i c 2{i " } (5.12)
Do i 'Ci * }
Hi
rH 3 m*3/2 (5.13)
i=l m i 2
Figures 5.5 and 5.6 summarize the results of equation (5.13) as a
function of temperature and dopant density. These figures show that the Hall factor ranges theoretically between 1.73 and 0.77 for temperatures between 100 and 400 K and dopant densities between 1014 and 1018 cm3 For temperatures above 200 K, rH becomes less than unity for dopant 15 - 3
densities greater than 5.5xi0 cm Figures 5.7 and 5.8 show the
theoretically predicted Hall mobility as functions of temperature and dopant density. These two figures show the results of evaluating equation (5.11) with the aid of numerical integration, and adjusting the lattice scattering mobility to give the best fit to values of conductivity mobility deduced-from resistivity measurements.
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