The luminescence of LaOBr:Ce

LaOBr:Ce

Tb and LaOBr:Tb phosphors under UV and cathode ray excitation has been studied.The excitation spectra of Tb

3+

ion in LaOBr:Tb consists of a strong broad 4f→5d transition band at 254nm and some weak 4f→4f transition lines in the wavelength range of 300-400nm.The excitation bands of LaOBr:Ce at 352.5

314.5 and 289nm originate from transition between the 4f-ground state(7F)and the 5d-excited state(2D).The excitation spectrum of Tb

3+

ion in LaOBr:Ce

3+

Tb

3+

consists of four bands at 254

289

314.5 and 352.5nm due to Tb

3+

and Ce

3+

.It is clear that only the excitation bard at 254nm belong to Tb

3+

ions and the other three bards are the excitation bands of Ce

3+

ion.With increasing Ce

3+

concentration the intensity of Tb

3+

excitation band at 254nm decreases

at the same time the intensities of the Ce

3+

excitation bands at 289

314.5 and 352.5nm increase.