We have been able to discount three point defects as the factor limiting GaInNAs material quality by comparing samples grown by two different growth techniques. Samples with vastly different concentrations of hydrogen and carbon have very similar properties in terms of deep levels, mobilities, and minority-carrier lifetimes. In addition, growth of hydrogen-free samples and corresponding measurements of vacancies provide strong evidence that gallium vacancies have an effect, but are not a limiting defect. (C) 2002 Elsevier Science B.V. All rights reserved.