The ultraviolet irradiation degradation of fluorescent lamp used BaMgAl10O17:Eu2+,Mn2+ phosphor

The ultraviolet irradiation degradation of lamps using BaMgAl₁₀O₁₇:Eu²⁺,Mn²⁺ phosphor is investigated. The X-ray photoelectron spectra demonstrate that the oxidation of Eu²⁺ is taking place during ultraviolet irradiation in air. The experiment in nitrogen indicates that the oxidation of Eu²⁺ is directly related to the oxygen in air and should be mainly responsible for the degradation of Eu²⁺. It reveals that the Mn²⁺ centers always remain stable during irradiation but its emission is involved in the energy transfer of Eu²⁺→Mn²⁺. Thus, the oxidation of Eu²⁺ also leads to the degradation of Mn²⁺.