Structural and spectral properties of triple-color emitting Eu doped SrZr4(PO4)6 phosphors: Plant growth LEDs application

Objective: Well known that the light energy is essential and major source for natural plant habi-tats, and the primary source of light is the sun. However, there is a lack of sun shine, particularly at dark places such as indoors, natural caves, northern countries, and night times that may destroy plants growth, stop blooming flowers, and decrease crop yields. Thus, artificial light sources are necessary for plant growth, not affecting natural plant habitats.Methods: In this work, we have prepared blue, red, and far-red light-emitting Eu doped SrZr4(PO4)6 phosphors by simple sol-gel method. The phase analysis, functional, and morpho-logical studies were carried out. The rhombohedral structures of phosphors were observed from the morphological graphs. XPS studies were confirmed the elemental and valance state of Eu2+ and Eu3+. The optical properties were systematically investigated through photoluminescence excitation and emission spectra, diffuse reflection spectra, and CIE chromaticity coordinates.Results: The band gaps of samples were found to be from 3.8 to 3.9 eV. The emission spectra of SrZr4(PO4)6:Eu phosphors exhibited a strong narrow band peaking at blue (452 nm), red (610 nm) and far-red (744 nm) emissions under the 390 nm excitation that nearly matches for the photosynthesis process; hence, we expect that the prepared phosphors may be a potential phos-phor material for the fabrication of plant growth WLEDs. Among all the phosphors, SrZr4(PO4)6:0.07Eu phosphor has maximum intensity, and its CIE coordinates, CRI and CCT, were found to be (0.34, 0.32), 91 and 4956 K, respectively.

Automated summary

Artificial light sources are necessary for plant growth in locations with insufficient sunlight. This study prepared Eu-doped SrZr4(PO4)6 phosphors emitting blue, red, and far-red light, which could potentially be used in WLEDs for plant growth. The phosphors showed strong emissions at specific wavelengths under excitation, suitable for the photosynthesis process.