Defect nature of the 0.4-eV center in O-doped GaAs

Abstract

We have studied the Ec −0.4 eV center in O-doped GaAs by a combination of temperature-dependent Hall-effect measurements, spark-source mass spectroscopy, and secondary-ion mass spectroscopy. The conclusion is that neither O nor any other impurity can account for the 0.4-eV center; therefore, it is a pure defect.