There are many kinds of organic small molecule Photoluminescent films, most of which contain conjugated heterocyclic ring and various chromophore groups, and the structure is easy to adjust. By introducing unsaturated groups such as ene bond and benzene ring and various chromophore groups to change their conjugate length, the photoelectric properties of the compound will change. Examples include oxadiazole and its derivatives, triazole and its derivatives, rhodamine and its derivatives, coumarin derivatives, 1, 8-naphthalimide derivatives, pyrazoline derivatives, trianiline derivatives, porphyrins, carbazole, pyrazine, thiazole derivatives, and perylene derivatives. They are widely used in optical electronic devices, DNA diagnosis, photochemical sensors, dyes, Photoluminescent brighteners, Photoluminescent coatings, laser dyes , organic electroluminescent devices (ELD) and other aspects. However, small photoluminescent sticker film are prone to fluorescence quenching under the condition of solid state, and devices made by general doping methods are easy to aggregate and crystallize, so the life of devices decreases. So many researchers on the one hand to small molecule research, on the other hand to find better performance of luminous films, polymer luminous films came into being.
Organic polymer optical film is usually divided into three categories: (1) the side chain type: small molecule luminescence group articulated on polymer side chain, (2) the main chain of the conjugate type: all the molecules are a large conjugated polymer system, (3) the main chain of the conjugate type: luminescent centers on the main chain, but separated from each other between the luminescence center did not form a conjugated system. The polymer luminescent films studied are mainly conjugated polymers, such as polybenzene, polythiophene, polyfluorene, polytriphenylamine and their derivatives. There are also polytriphenylamine, polycarbazole, polypyrrole, polyporphyrin  and its derivatives, copolymers, etc., which have been studied more.
In addition, the luminescent group can be introduced into the end of the polymer or the middle of the polymer chain. Kenneth p. Ghiggino et al. introduced the fluorophore into RAFT reagent and connected the fluorophore to the polymer through RAFT polymerization. As can be seen from the above luminescent polymers, most of them are conjugated polymerization of the main chain. The main chain polymerization is easy to form a large conjugated area, but its solubility and fusibility are reduced, making it difficult to process. However, when the luminescent group is introduced into the end of the polymer or the middle of the polymer chain, only the end group glows, and the molecular weight is not very large. If the molecular weight is very large, the content of the luminescent group in the polymer is low, and the fluorescence is very weak. The side chain polymer luminescent film is a strong complement to the main chain conjugated polymer.
- This film is often referred to as a photoluminescent object. Self-luminous objects may glow in the dark, but do not need to be exposed to sunlight beforehand. These films, often used as luminous markers on the dial and for making objects that glow for long periods of time, contain radioactive elements.
- Phosphorescent films are also often referred to as photoluminescent films because of their phosphorous content.
Application of photoluminescent film digital printing: photoluminescent powder is an ideal film for making luminescent ink, luminescent paint, luminescent plastics and luminescent printing paste. Ink not only suitable for screen printing all kinds of luminous effect the patterns of the text, such as signs, toys, calligraphy and painting, glass painting, stickers, etc., but also because of its high transparency, good film-forming, thin coating, etc, can be in all kinds of embossing, the round (figure of Buddha, porcelain like, plaster model, the tang), polymer lighting and crafts such as painting, spray or screen printing, without affecting the original act the role of color or line under the premise of greatly improve its added value. Luminous ink color: transparent, red, blue, green, yellow and so on.