Luminescence Properties of LnZr(BO₃)₂:Re (Ln=Ba, Sr; Re=Eu, Ce,Tb)

The excitation spectrum of BaZr(BO3)(2):Eu3+ is composed of two broad bands. One band in the range from 120 nm to 170 nm is attributed to the borate groups, and the other band at 230 nm is due to the charge-transfer state (CTS) of the Eu3+ ion. The excitation spectrum of BaZr(BO3)(2):Tb3+ consists of one broad band in the range from 120 nm to 170 nm and the bands peaking at 226 nm, 245 nm and 272 nm respectively. The former is also attributed to the absorption of the BO3 groups. The latter correspond to the 4f(8)-4f(7)5d transition of Tb3+ Main peak of the host absorption moves about 30 nm to high energy region as Sr2+ replaces Ba2+ partially.