excimer

An excimer is a temporary, excited-state molecule formed when two atoms, typically of noble gases like krypton or argon, come together only when energized by a source such as an electric current or light. These molecules exist briefly and then release energy as ultraviolet light when they return to their normal state, causing a specific type of glow. Excimers are important in applications like laser technology and ultraviolet light sources because of their ability to produce intense, precise ultraviolet radiation in a controlled manner.