The formation of nitrogen-induced defects and the reduction of their concentration after rapid thermal annealing in TlInGaAsN alloy system are studied in detail, employing the photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) studies. XPS analysis revealed that the N-induced defect configurations are most likely attributed to the N-As spilt interstitials and (N-As-As-Ga) nearest neighbor pairs. Rapid thermal annealing (RTA) treatment reduces the defect concentration and induces a significant improvement in the PL efficiency of the TlInGaAsN material system. (C) 2013 Elsevier B.V. All rights reserved.