Enhanced red luminescence from GdAl 3 (BO 3 ) 4 : Pr 3+ phosphors under NUV excitation.

The GdAl 3 (BO 3 ) 4 :xPr 3+ (0 ≤ x ≤ 5.0 mol%) phosphors were prepared through solid state reaction route and characterized for various lighting applications. Powder X-ray diffraction investigations revel rhombohedral structure matched to JCPDS card no. 83-1907. The morphological studies confirm the agglomeration of particles with different size and shape. The emission spectra show various emission transitions originating from Pr 3+ :( 3 P 1,0 , 1 D 2 ) emission states to their lower lying energy states upon 274 nm NUV excitation with a red shift for x > 0.5 mol%. The colour perception analysis results an intense red luminescence due to efficient energy transfer from Gd 3+ to Pr 3+ ions. The temperature-dependent luminescence investigations show good thermal stability even beyond 150°C with an activation energy of 0.24 eV. The observed experimental results show the potentiality of GdAl 3 (BO 3 ) 4 :0.5 Pr 3+ phosphor for red emitting devices and red component in phosphor converted white LEDs.