Abstract: Method of preparing a metal oxide layer on a substrate, in which the following successive steps are carried out: a) a metal oxide powder is dispersed in a liquid medium comprising a dispersion solvent and a dispersant, the said liquid medium containing neither plasticizer nor binder, by means of which a suspension A of the said metal oxide powder in the said liquid medium is obtained; b) a solution of at least one polymer in a solvent is added to the said suspension A, by means of which a suspension B is obtained; c) suspension B is deposited on the substrate by a dip coating method, by means of which a green layer is obtained; d) the green layer obtained in step c) is dried; and e) the dried layer obtained in step d) is calcined.