InGaN/GaN heterostructures have been deposited by MOVPE onto (0 0 0 1) sapphire substrates. It has been noted that the Indium incorporation efficiency depends on different growth parameters, namely the growth rate, reaction kinetics and partial pressure of H, in the reaction cell. In this work the InGaN composition has been investigated by different techniques and the incorporation efficiency of indium is then correlated with substrate temperature, substrate rotation, H-2 partial pressure and input flows of TMG and TMI. (C) 2004 Elsevier B.V. All rights reserved.