Engineering efficient blue and far-red dual-emitting phosphor for plant growth

The combination of indoor plant growth lamps and soilless cultivation is considered as a promising direction for future agricultural technology. Its environmentally friendly, effective, and energy-saving characteristics make the plant lighting phosphor widely concerned. However, the phosphor with the required emission spectrum for plant growth while simultaneously achieving dual emission of blue and far-red light is still rarely developed. To address this challenge, a series of Sr2GdGaO5:Bi3+, Sr2GdGaO5:Mn4+, and Sr2GdGaO5:Bi3+, Mn4+ phosphors have been designed and thoroughly characterized in terms of their phases, morphologies, and optical properties. Dual emission of Sr2GdGaO5: Bi3+, Mn4+ in blue light (475 nm) and far-red light (726 nm) regions is observed under 350 nm ultraviolet light excitation, and the energy transfer mechanism determined to be dipole-dipole interaction. A high coincidence between plant growth absorption spectrum and co-doping induced double emission is realized. Tremendous acceleration of garlic and bean seedling growth can be observed under the illumination of phosphor-encapsulated LED in soil-free conditions. This comprehensive work contributes to the understanding and utilization of phosphors for efficient indoor plant lighting applications and opens new possibilities for energy-saving and effective plant cultivation.