Diphenyliodonium iodide is widely used as a photoinitiator in the polymerization of various resins and coatings. It is particularly effective in UV-curable systems, where it facilitates rapid curing and enhances the durability of the final product. This compound is also employed in the synthesis of organic compounds, serving as a key reagent in iodination reactions. Additionally, it finds application in the field of electronics, where it is used in the production of conductive polymers and advanced materials. Its ability to generate reactive species under light exposure makes it valuable in photolithography processes for microfabrication.