Enhanced luminescence performances of Mn4+:Y3Al5O12 red phosphor by ions of Rn2+ (Be2+, Mg2+, Sr2+, Ba2+)

In recent times, white-light emitting diodes (W-LEDs) have been widely used as light sources. However, most of the commercial lamps lack the red-light component. Herein, study on a novel blue-light activated alkaline earth ion doped Mn4+:Y3Al5O12(Mn4+:YAG) phosphor, exhibiting a strong red emission that is attributed to the Mn4+: 2Eg→4A2g spin-forbidden transition in the 650-750 nm spectral region, that can be excited by both near-ultraviolet and blue chips is presented. The dopants Be2+, Mg2+, Sr2+, and Ba2+ were found to be significantly beneficial for enhancing Mn4+ luminescence, the related mechanism is systematically discussed here. In addition, the concentration quenching is systematically investigated. The crystal field strength (Dq) and the Racah parameters (B and C) are carefully calculated. After incorporating Mn4+/Be2+:YAG phosphors (glass ceramics) and GaAG phosphors into a blue LED device, white light with a high color rendering index and a low correlated color temperature is successfully obtained. Therefore, the Mn4+/Be2+:YAG phosphor can serve as color converter for application in W-LED.