Enhanced red luminescence in CaAl12O19:Mn4+via doping Ga3+ for plant growth lighting
A series of solid solution CaAl12−xGaxO19:Mn4+ phosphors were prepared via a high-temperature solid-state reaction. Their structural properties were characterized by X-ray diffraction (XRD) and the luminescence was investigated via photoluminescence spectra. The obtained CaAl12−xGaxO19:Mn4+ phosphor has a strong broad excitation band in the range of 250–550 nm, which can be easily excited by the UV, NUV and blue light, and a broad emission band centered at 655 nm between 600 nm and 800 nm due to the 2Eg → 4A2g transition of the Mn4+ ion. The PL spectra indicate that the intensity of CaAl12O19:Mn4+ can be enhanced when the Ga3+ concentration equals 1. Furthermore, the element mapping, optical properties, thermal stability, fluorescence lifetime and CIE chromaticity reveal that the CaAl12−xGaxO19:Mn4+ phosphors can be considered as potential candidates in indoor plant cultivation.