Adjustable ultraviolet and white light dual emission phosphor Y2Sr(Ga1−yAly)4SiO12:xPr3+ for health lighting

Abstract

Mid-ultraviolet light (290–320 nm) can promote human vitamin D synthesis, which helps in the prevention and treatment of rickets and cartilage disease. For people who lack sufficient ultraviolet radiation all year round, it is significant to supplement the ultraviolet component in daily lighting sources. However, there are few luminous materials showing a combination of mid-ultraviolet light and white light emission on the market. Here, we designed a new material, Y₂Sr(Ga_1−yAl_y)₄SiO₁₂:xPr³⁺ (YSGAS:xPr³⁺), which achieves dual emission of 320 nm ultraviolet and white light from a single substrate with a single doped phosphor. Without Al³⁺ ions, the emission intensity of the Y₂SrGa₄SiO₁₂:xPr³⁺ phosphor shows a contribution-dependent relationship, and concentration quenching due to exchange interaction. The crystal field environment was regulated by partially replacing Ga³⁺ ions with Al³⁺ ions. After introducing Al³⁺, YSGAS:xPr³⁺ phosphors exhibit dual ultraviolet emission (320 nm) and visible light emission. The emission color of YSGAS:xPr³⁺ can be adjusted by changing the Al³⁺ concentration, and Y₂Sr(Ga_0.6Al_0.4)₄SiO₁₂:1%Pr³⁺ emits both ultraviolet light and white light. The LED device prepared by using the YSGAS:Pr³⁺ phosphor and chips shows a color temperature of 4858 K and appropriate CIE coordinates of (0.3474, 0.3390), indicating wide application prospects in the field of “health lighting” for particular populations.