The emission spectra of Na Gd minus xEux MgWO phosphors

Firstly, the absorbed excitation energy from 395 nm (7F0 → 5L6) at higher level relaxed to lower 5D0 level via the non-radiative multiphonon interaction. Meanwhile, no emissions from higher excited levels of 5DJ (J = 1–3) to 7FJ were observed still due to that fast multiphonon relaxation to 5D0 level, and the emissions from 5DJ (J = 1–3) to 7FJ are several orders smaller than that of 5D0 → 7FJ.