A novel efficient single-phase dual-emission phosphor with high resemblance to the photosynthetic spectrum of chlorophyll A and B

Abstract

Light is a fuel for photosynthesis and plays an irreplaceable role in seed germination, stem elongation, leaf expansion, flowering induction, and accumulation of nutrients. However, the current phosphors combined with LEDs for photosynthesis have some unsolved problems, such as low efficiency, poor thermal stability, unvarying emission wavelength or non-matching spectrum, which restrict their applications. In this work, a series of novel efficient Lu₃Al₅O₁₂:10%Ca²⁺,xBi³⁺,yMn⁴⁺ phosphors with blue-violet plus deep red dual-emission peaking at 419 and 669 nm have been first reported, which can meet the different light requirements of plants by controlling the concentration ratio of Bi³⁺ and Mn⁴⁺, and they possess at most 90.64% spectrum resemblance to the absorption spectrum of chlorophyll A and B. Furthermore, these phosphors exhibit high internal efficiency and at most reserve 95% of the initial intensity at 425 K. Finally, as a light source for monitoring the fluorescence spectra of evergreen plants, pc-LEDs were fabricated by UV chips and our synthesized phosphors. The results reveal that these phosphors can achieve as high as 83% photosynthetic efficiency for evergreen plants and improve it by 10% than a single emission phosphor, which shows good application prospects for improving plant photosynthesis.