Abstract Doping elements play an important role in the early stage of heteroepitaxial growth by liquid-phase epitaxy (LPE). It is found that uniform growth of AlGaAs on chemically-etched (111)B GaP substrates can be obtained by doping with group VI elements, Te or Se, into the melt for LPE. From Nomarski microscopic observation of the heterointerface after selective etching of epitaxial layers, it can be explained that such a dopant has an important effect on suppressing the meltback of GaP substrates and causes an acceleration of two-dimensional growth. Other dopants such as Mg, Zn, Si, Ge or Sn produce only hexagonal island growth, similar to the case of undoped growth. Moreover, multilayer growth has a clear effect of reducing the dislocation density in the epitaxial layer.