High Temperature Synthesis of Yellow-emitting Y₂BaAl₄SiO₁₂:Ce³+ Phosphors for WLED Applications

Phosphor converted white light-emitting diodes have widely been applied in solid-state lighting technology based general illuminations owing to their significant advantages, such as high luminous efficiency, long working lifetime, eco-friendly nature, high reliability, remarkable energy saving and compact design. The common approach to the generation of pc-WLED is the combination of blue chip LED and yellow-emitting Y2Al5O12:Ce3+ (YAG:Ce3+) phosphors. These WLEDs show high efficiency due to the allowed 5d-4f transition of Ce3+. In this work, yellow-emitting Y2BaAl4SiO12:Ce3+ (YBAS:Ce3+) phosphors were synthesized by a sol-gel method. The structural, morphological and luminescence properties of YBAS:Ce3+ phosphors were analyzed. To examine the potentiality in outdoor lighting, a cool WLEDs were fabricated by using a blue chip LED combined with YBAS:Ce3+ phosphors. The phosphors can efficiently be excited by the blue light, which realized an intense yellow emission with the emission peak centered at 530 nm. Using the synthesized YBAS:6Ce3+ phosphors, white light-emitting diodes (WLEDs) were fabricated. The CIE chromaticity coordinates of YBAS:Ce3+ and fabricated WLEDs located at (0.391,0.563) and (0.265,0.326), respectively.