Аннотация:Epitaxial layers of YAl3(BO3)4 co-doped with Er3+ and Yb3+ are grown from K2Mo3O10–(Y/Yb/Er)2O3–B2O3 complex flux melt by means of liquid phase epitaxy (LPE) technique. The morphology, structure and composition of the layers are investigated. Epitaxial layers with a thickness of 110 μm were obtained on laser-quality substrates, corresponding to a growth rate of 4.6 μm per hour. The segregation coefficients for Er3+ and Yb3+ cations are close to unity. The layers exhibit hexagonal huntite-type structure (sp. gr. R32) and small unit cell misfit with respect to the substrate. The absorption and emission spectra and the fluorescence lifetimes have been measured.