An easy route to pure and luminescent Eu-doped YVO4 polycrystalline films based on molecular or hybrid precursors

摘要

An easy "soft-chemistry" method has been developed to prepare pure and luminescent Eu-doped YVO_4 films. The method is based on the spin-coating of aqueous solutions of stoichiometrically well-defined yttrium(III)- and/or dioxidovanadium(V)-edta complexes, sometimes in the presence of a cellulose derivative, namely (hydroxypropyl)methyl cellulose. Films of the corresponding binary oxides, Y_2O_3 and V _2O_5, were also studied for comparative purposes. XRD, Raman spectroscopy and scanning electron microscopy were used to characterize the samples at different stages of their preparation. The spin-coating rate as well as the presence of the cellulose derivative in the precursor solutions were found to influence greatly the homogeneity and morphology of the films. The preferential orientation of crystallites within some of the films was also evidenced.