Self-assembled InAs quantum dots (QD) over an InGaAs layer on InP substrates were grown by metal-organic chemical vapor deposition (MOCVD). Their structural and optical properties were investigated by atomic force microscopy (AFM) and photoluminescence (PL). We have studied the effect of QD deposition time, its growth temperature and InGaAs mismatch on the dots density, height, homogeneity and PL spectra. Optimized stacks of structures were grown for a QD infrared photodetector (QDIP) and their absorption was measured. (C) 2004 Elsevier B.V. All rights reserved.