Layers of epitaxial gallium phosphide doped with either tellurium, sulphur or zinc over the range 10 '~ to 10 '8 cm-2 have been grown from gallium solution using a vertical dipping system. These layers of thickness 60 to 80 /~m have been produced on the (1 00) and (111)B faces of gallium phosphide single crystal substrates at high growth rates. Doping gradients have been investigated by a Schottky barrier technique over an angle lapped region of the grown slice, measuring the capacitance voltage characteristics of the individual barriers. Significant changes in doping level have been observed throughout the thickness of the layers and these are related to the variation of distribution coefficient, the losses of impurity from the system and the presence of competing background impurity systems.