Changes in the Electronic Properties of Bulk GaAs by Thermal Annealing.

Bulk GaAs grown by the Bridgman technique changes its electronic properties in response to heat treatment. These changes were studied by deep level transient spectroscopy, photoluminescence and Hall effect measurements. We report the dependence of the conductivity changes on starting material composition,annealing temperature, and annealing duration. The changes are related to the equilibration of native defects introduced during the crystal growth process. The implication of this study is that As-grown GaAs is a metastable material with its ultimate electrical properties being determined by process conditions.