EXCIMER LAMP

According to international studies, UV light at the 222-nm wavelength has similar germicidal capabilities of the more widely used 254-nm UV light to kill or inactivate pathogens (bacteria and viruses), but it does not produce the same damaging effects on skin or eyes as 254-nm light.

One of the most promising methods of generating 222 nm UV-C light is through an optically filtered krypton-chloride (KrCl) excimer lamp. A high electric field generates plasma by exciting KrCl excimer molecules between the electrodes. When the excimer molecules dissociate and return to their original state (ground state) within nanoseconds, they trigger the emission of 222 nm UV light.

Origin of the name excimer: excited dimer, i.e. excited diatomic molecule 

Krypton is a noble gas. Noble gases do not react in the ground state. Upon excitation, chlorine combines with krypton gas to form a diatomic excimer molecule KrCl.