The effects of thermal annealing on the emission and microstructural characteristics of GaAs0.88Sb0.10N0.02/InP multiple quantum well (QW) structures were studied by photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM). The results show that the optimum annealing conditions lead to improved PL intensity accompanied by only a small blue shift, contrasting the behavior of GaAsSbN /GaAs multiple QWs, and improved structural uniformity. (C) 2007 Elsevier B.V. All rights reserved.