Enhanced red luminescence in CaAl12O19:Mn4+via doping Ga3+ for plant growth lighting

Abstract

A series of solid solution CaAl_12−xGa_xO₁₉: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 CaAl_12−xGa_xO₁₉: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 ²E_g → ⁴A_2g 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 CaAl_12−xGa_xO₁₉:Mn⁴⁺ phosphors can be considered as potential candidates in indoor plant cultivation.