Multifunctional Pr3+ single doped CaLaMgTaO6: Crystal structure, thermal behavior and applications

Abstract

This paper, for the first time, presents a comprehensive study of the structure, thermal stability and photoluminescence properties of CaLaMgTaO6:Pr3+ phosphors for LED applications. Pr3+ ions exhibits two clusters of dominant emissions peaked at 495 nm (3P0→3H4) and 657 nm (3P0→3F2) from double perovskite-structure CaLaMgTaO6 compounds. Meanwhile, the samples cover the emission wavelength of commercial blue light-emitting diode (LED) chips with high internal quantum efficiency (IQE) of 30.25% upon 450 nm excitation. The mechanism of thermal quenching for this phosphor was investigated and the corresponding activation energy ΔE was determined to be 0.23 eV. The fabricated Pr3+ single doped CaLaMgTaO6 together with a 450 nm blue LED chip is well-matched with the absorption band of photosynthesis, phototropism, and photomorphogenesis. Furthermore, this phosphor along with commercially available phosphors was applied to fabrication of 450 nm UV chip and YAG:Ce3+ emitted a well-distributed warm white light with high color rendering index (CRI) of 84.1 and a correlated color temperature (CCT) of 3914 K. All of the results indicate that this novel phosphor can compensate for the red light and has potential applications in plant cultivation and warm white LEDs field.