;elf-organized GaxIn1-xNyAs1-y quantum dots (QDs) were fabricated on GaAs (001) substrates by atomic hydrogen-assisted molecular beam epitaxy with a radio frequency nitrogen plasma source (RF-MBE). We have investigated the effect of N-2 flow rate on growth dynamics and optical properties of GaInNAs QDs. With increasing N-2 flow rate, both the QD size and size fluctuation became significantly larger possibly due to phase separation and non-uniformity of N atom concentration, thereby causing linewidth broadening of PL emission of band-to-band transition. We found that N-2 flow rate during the growth of GaInNAs QDs on GaAs (001) in RF-MBE strongly affects the growth kinetics and optical properties. Further, appropriate post-growth annealing was found to be effective in improving PL emission efficiency of both thin GaInNAs films and QDs. Finally, we obtained high-quality 1.3-mum wavelength PL emission with a narrow linewidth of 98.4 meV at room temperature from optimally annealed GaInNAs QDs. (C) 2004 Elsevier B.V. All rights reserved.