Blue Luminescent Phosphor Sr₃Y_1−X(BO₃)₃:_XBi³⁺ for WLED Applications

Abstract

Abstract The polycrystalline powder sample of Bi 3+ ‐activated strontium yttrium borate phosphor Sr 3 Y 1−x (BO 3 ) 3 : x Bi 3+ (x = 3, 4, 5 mole%) is prepared by solution combustion technique. Formation of phosphor in the desired crystalline phase is confirmed by powder X‐ray diffraction characterization and FTIR, SEM images of the synthesized phosphor show the irregular grains with average particle size 2.5 µm. Luminescence properties of the synthesized phosphor are investigated at room temperature. The excitation spectrum consists of a single broad absorption band from 200 to 370 nm with the prominent excitation peak at 336 nm [ 1 S 0 to 3 P 1 of Bi 3+ ions] and weak excitation peak at 254 nm [ 1 S 0 to 1 P 1 of Bi 3+ ions]. Strongest emission peak of 492 nm wavelength that is of blue light is observed at 336 nm UV light excitation. Sr 3 Y 1−x (BO 3 ) 3 : x Bi 3+ phosphor emits blue light. As Bi 3+ is sensitive to the surrounding crystal field environment it shows weak excitation peak at 254 nm, which gives emission at 413 nm. Hence, Sr 3 Y 1−x (BO 3 ) 3 : x Bi 3+ is new UV excited blue emitting phosphor useful for UV/blue chip WLEDs.