Three processes for making phosphor films are described. One process for activated with Cu, Ag, or Mn involves evaporation of powder phosphor onto a room‐temperature substrate followed by heat treatment of the film in an atmosphere. A process for alone involves the single step of evaporating the phosphor onto a substrate held between 250° and 400 °C. The third process involves evaporating the phosphor in a single step onto a heated substrate in a uniformly heated enclosure such as the “Hot Wall Bell Jar.” A fourth process used for silicate, phosphate, and borate phosphors involves a reaction during the course of evaporation between and a heated substrate.