GaAs1-xBx alloy was grown by atmospheric-pressure metalorganic vapour-phase epitaxy using a horizontal reactor. GaAs1-xBix epilayers were elaborated on exactly (1 0 0)-oriented p-GaAs substrates. Trimethyl-gallium, trimethyl bismuth (TMBi), and arsine were used as precursor sources at a growth temperature of 420 degrees C within a very narrow range of V/III ratios and molar flow rates of TMBi. The lattice mismatch between the layer and the substrate was examined by using high-resolution X-ray diffraction technique. The measurements were performed on (0 0 4) and (1 15) planes. The solid composition of GaBi content in the GaAs1-xBix alloy reaches a maximum value of about 3.7%. In analyzing the surface morphology, scanning electron microscopy (SEM) and SEM-energy dispersive X-ray spectrometer were used to qualify films properties. (c) 2006 Elsevier B.V. All rights reserved.