A new approach to the growth of abrupt heterojunctions by MOVPE in which the substrate is moved from one gas stream to another is reported. The technique has been demonstrated by successfully growing both single thick layers and multi-quantum-well layers of GaInAs and InP. The structures were grown at one atmosphere using preformed adducts and the material was assessed using double crystal X-ray diffraction, transmission electron microscopy (TEM) and photoluminescence (PL) techniques and found to be of high quality.