Abstract :
Temperature-dependent Hall effect measurements have been performed on a set of Ge-doped and Ge/Te-codoped In0.5Ga0.5P epilayers grown by liquid phase epitaxy. The compensation ratios (NA/ND) and the activation energies have been evaluated by fitting the temperature-dependent carrier concentration data. It is seen that the Te codoping increases the free electron concentration and reduces the ionization energy and the compensation ratio. The result suggests that, with the optimum Te codoping, the amphoteric dopant Ge is more substituted to III site rather than V site and thus more Ge impurities act as donors to increase the n-type concentration. In the temperature range studied, the mobility decreases with increasing carrier concentration, which shows the dominant features of the ionized impurity scattering.
