The present invention relates to a red light phosphor, which is based on sulfide and activating agent containing rare earth strontium or hafnium. It is characterized by that the aforementioned materials are a fluorine-sulfur oxide containing lanthanum-yttrium-zirconium and/or hafnium with its stoichiometric formula as (La1-x-y-zYxAyMez+4O)2S1(F−1)2z, and activating agent based on A=(TR+3=Σ Eu, Sm, Gd, Tb)+(TR+4═Pr+4), in which Me+4=Zr+4 and/or Hf+4. Compared with standard materials, the luminous intensity of the phosphor according to the present invention is increased to 1.6-2.4 times. Further, the red light phosphor according to the present invention has a mean diameter of d50≈0.6 μm. The present invention also discloses a multilayer photo-transforming film, in which the three-layer agro-film is filled with phosphor. The agro-film is based on polythene and its derivatives and added with photostabilizer.