Dual spectra band emissive Eu²⁺/Mn²⁺ co-activated alkaline earth phosphates for indoor plant growth novel phosphor converted-LEDs

This paper reports designing a novel single composition blue/red color illuminating phosphor followed by fabricating "smart" agricultural/horticultural LED lighting. Color-tunable Eu²⁺/Mn²⁺ co-activated alkaline earth phosphates, Na(Sr,Ba)PO₄ and Ca₃Mg₃(PO₄)₄, are considered, and the stable doping sites for the corresponding activators are identified by using first-principle DFT calculations. We can realize the designated color purity with stable thermal quenching preserved luminescence behavior is induced by the Eu²⁺ center positioned at different coordination states with intermixed Sr²⁺/Ba²⁺ sites in Na(Sr,Ba)PO₄ hosts. Moreover, we demonstrate that the resultant LED lighting adopting the proposed novel phosphor composition stimulates the enhanced photosynthesis reaction for indoor hydroponics plants, such as oats and onions, which is superior to the narrow line emission band induced by the mixture of conventional red/green/blue LEDs. Thus, using the color-tunable single composition luminescent material may produce an innovative energy-efficient artificial lighting for indoor plant growth.