CATHODOLUMINESCENCE EMISSION-SPECTRA OF TRIVALENT EUROPIUM-DOPED YTTRIUM OXYSULFIDE

Europium-doped yttrium oxysulphide phosphor (Y2O2S : Eu3+) was prepared. Y2O2S : Eu3+ was found to have a hexagonal structure with lattice parameters a = 0.3776 nm and c = 0.6538 nm. The cathodoluminescence emission spectra Of Y2O2S : Eu3+ were recorded between 400 and 635 nm at both 77 and 293 K. Most of the numerous emission lines were assigned on the basis of known energy levels of Eu3+ ions, crystal field splittings, and selection rules. More attention was paid to the high-intensity emission lines in the spectral red region, because this phosphor can be used as an efficient red-emitting phosphor in colour televisions. The highly intense lines at 611.3, 61 6.9 and 626.5 nm are attributed to the transitions from 5D0 to one of the Stark components of the F-7(2) level. The other transitions from 5D1, 5D2 and 5D3 to F-7(J) (J = 0, 1-5) were found and assigned.