Bulk GaAs crystals (up to 4 mm thick and 20 mm in diameter) were grown by liquid phase electroepitaxy on melt-grown GaAs substrates. They were found to be of high quality (essentially dislocation-free) comparable to that of thin GaAs epitaxial layers; when undoped they exhibited a very high electron mobility (about 7000 cm 2/V·s at room temperature) low carrier concentration ( <10 15 cm -3), and no measurable electron traps. The thickness of the crystals and maximum growth rate were found to be limited primarily by convection in the solution. In view of the limitations imposed by convection, the growth of commercial size bulk GaAs crystals of epitaxial quality is being designed under microgravity conditions.