UV and Vacuum Ultraviolet Luminescence Properties of LaP3O9 : Eu3 +

The photoluminescence (PL) properties of La 1-x P 3 O 9 :Eu 3+ x (0 < x ≤ 1) in the UV and vacuum ultraviolet (VUV) region were investigated. The absorption bands of P 3 O 3- 9 groups in Li 0.9 P 3 O 9 :Eu 3+ 0.1 ) are observed in the region of 132-187 nm. It has been found that the position of the charge transfer (CT) band of Eu 3+ -O 2- has a blueshift about 11 nm when the excitation energy is changed from UV to VUV. The CT band of La 3+ -O 2- is located at 205 nm and overlaps the CT band of Eu 3+ -O 2- , which indicates the VUV excited energy could be efficiently transferred to Eu 3+ . Under 147 and 172 nm excitation, the strongest emission peak of La 1-x P 3 O 9 :Eu 3+ x (0 < x ≤ 1) is located at 616 nm and no concentration quenching is obtained. The PL intensity for La 1-x P 3 O 9 :Eu 3+ x is about 68% of that for (Y,Gd)BO 3 :Eu 3+ under 172 nm excitation.