Current Carrier Lifetimes Deduced from Hall Coefficient and Resistivity Measurements

The conventional expression for the Hall coefficient in semiconductors is based on the assumption of an infinite rate of carrier recombination. If the latter assumption is not made, diffusion currents are present which change the value of the Hall coefficient. It is this change in the Hall coefficient which forms a basis for an independent measurement of carrier lifetime. Methods for obtaining the value of a parameter $m$ which contains the bulk lifetime $\tau$ and the surface recombination velocity $s$ are described. Lifetimes, as deduced from Hall measurements, compare reasonably well to lifetimes obtained on the same samples by injection methods.