A deep (0.82 eV) impurity level has been observed via transient capacitance measurements in GaAs prepared under various gas‐phase stoichiometries. The density of these impurities increased with increasing AsH3/GaCl ratio in the vapor phase ranging from 2×1013cm−3for a 1/3 ratio to 9×1013cm−3for a 3/1 ratio. The minority‐carrier lifetime in these same samples decreased from 15 to 5 nsec with increasing AsH3/GaCl ratio. These deep levels, which serve as recombination centers for lifetime reduction, appear to originate from point defects introduced by deviations from stoichiometry toward the As‐rich side.