Structural Development and Luminescent Enhancement of CaAlSiN3:Eu2+ Phosphor via Replacing Al3+ by Ga3+

Abstract The preparation of high intensity red emitting Eu2+ doped CaAl1-xGaxSiN3 solid solution phosphor was successfully achieved by using a low-temperature, low-pressure, solid-state synthesis method with the efficient substitution of GaN. For the experiment, GaN is more active than AlN, so it is much simpler to engage in reactions at lower temperatures. DFT calculations were used to check the structure stability and influence of Ga3+ substitution in CaAlSiN3 host lattice. The findings of the experiments revealed that the excitation spectra had a broad spectrum from near-UV to visible light. The electronic transition between the valence and conduction band of CaAlSiN3 host lattice causes the dominant peak at 240 nm. The peaks at 320 and 460 nm are attributed to the 4f7 to 4f65d transition of the Eu2+ activators. Broadband emission, ranging from 500 nm – 800 nm was observed in all the analyzed phosphors samples. Due to high crystallinity, a high-quality final product of CaAl1-xGaxSiN3:0.016Eu2+ phosphors powder was formed with (x=0.00 to 0.20) GaN which caused an increase the emission intensity.