Luminescent films of ZnS [Mn], Zn<sub>2</sub>SiO<sub>4</sub> [Mn], Zn<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> [Mn], CaF<sub>2</sub> [Mn], and CaWO<sub>4</sub> [W] have been formed by evaporation in a vacuum and a subsequent heat treatment. Most of the films may be made either transparent or fogged depending on the post-heat treatment. The luminescent brightness of the fogged films, under cathode ray excitation, approaches the brightness of the bulk powdered material. The brightness of the transparent films is limited chiefly by internal reflection. In general, the phosphor chemistry of the powdered materials has been found to be applicable to thin films.
CHARLES FELDMAN and MARGARET O’HARA, "Formation of Luminescent Films by Evaporation," J. Opt. Soc. Am. 47, 300-305 (1957)