The effects of nitrogen (N) incorporation on the electron properties of GalnNAS epilayers grown by metal-organic vapor phase epitaxy (MOVPE) have been probed by the analysis of Hall-effect and persistent photoconductivity (PPC) measurement. From the analysis of temperature-dependent PPC decay kinetics of samples with different N content, we speculate that the effect of PPC in n-type GaInNAs can be ascribed to DX-type deep centers and N-induced defects undergoing large lattice relaxation upon photo-excitation. With further experimental supports to our interpretation, we have also observed that N-induced localization can be quenched through thermal annealing with different temperatures. (c) 2006 Elsevier B.V. All rights reserved.