Optical and structural characterizations were conducted on an InGaAsN quantum well (QW) with large energy bandgap barrier material consisting of InGaAsP (E-g = 1.62eV) grown by metalorganic chemical vapor deposition. A growth pause annealing technique substantially improves both the Structural and the optical quality of the QW. With an optimum growth pause of 14s, surface roughness reduces by 50% and photoluminescence intensity increases 25 times compared with the sample undergoing a 3-s growth pause. No significant emission wavelength blue shift was observed, indicating this growth pause annealing process involves a mechanism different from that of the conventional post-growth thermal annealing of InGaAsN QW. Preliminary results on InGaAsN-active diode lasers employing InGaAsP barrier material indicate performance is limited by nonradiative recombination. (C) 2004 Elsevier B.V. All rights reserved.