Novel Sm3+-Mn4+co-activated CaGdMgNbO6 red phosphor with anomalous thermal quenching for plant growth lighting

Red inorganic phosphors are widely utilized in the field of artificial plant supplemental lighting. Nevertheless, their red light emission falls short of satisfying the plant's dual requirements for both deep-red and far-red light simultaneously. In this work, multiple red emission Sm3+ and Sm3+-Mn4+ activated CaGdMgNbO6 (CGMNO) red phosphors were prepared by high-temperature solid-state reaction. The luminescence characteristics, thermal stability, energy transfer behaviour and optical temperature sensing properties were investigated. The 550-750 nm emission bands of CGMNO:Sm3+ and CGMNO:Sm3+, Mn4+ matched the absorption band of the plant. The inhibition of energy transfer between activated ions and the structural reconstruction of conduction band traps reveal the anomalous thermal quenching behavior of Sm3+ ions at high temperatures. These results show that Sm3+-Mn4+ co-activated CGMNO phosphors have potential applications in plant growth.