Abstract: A material formed as a film comprised of monomolecular layers (2,3,4,5) stacked on a substrate (1), wherein said film includes at least one first set (R) of layers which form an electric charge reservoir, and a second set (S) of layers which form a conductive cell and which contain a number of conductive copper oxide layers (4), separated from each other by intermediate layers (5), the reservoir and the conductive cell being adjacent in the layer stack. There are at least four conductive copper oxide layers, and the intermediate layers have the chemical formula Ca.sub.1-x M.sub.x and are free of strontium, wherein x is a real number between 0 and 0.2, M is a component with an ionic radius close to that of the Ca.sup.2+ ion, and the intermediate layers may be complete or not.

Abstract: Method of vacuum depositing a monomolecular layer on a surface, the monomolecular layer comprising at least one element selected from groups IIa, IIIa, IVa, VIIIa, Ib, IIb, IIIb, Vb of the periodic table. The method consists in heating said surface to a predetermined temperature (T) of less than 600.degree. C. and vacuum evaporating at least the above-mentioned element for the purpose of depositing it on the receptor surface, the total atomic flow of the element(s) onto the receptor surface being from 10.sup.12 to 10.sup.15 atoms/cm.sup.2 s. According to the invention, the formation of the monomolecular layer is monitored in real time, and evaporation of the element is stopped when the complete formation of the monomolecular layer is detected.