Tunable blue-red dual emission via energy transfer in Na4CaSi3O9: Ce3+, Mn2+ phosphors for plant growth LED

Along with the rapid development of modern agriculture, plant growth requires better light quality. Blue and red light play a crucial role in plant growth, so achieving blue-red dual light emission is urgently needed. The energy transfer (ET) between two independent luminous centers is an effective means to regulate the blue-red dual emission. Hence, Ce3+-Mn2+ co-doped Na4CaSi3O9 (NCSO) phosphors are successfully synthesized by a conventional high-temperature solid-state method. The crystal structure and phase purity of NCSO phosphors are confirmed by X-ray powder diffraction (XRD) and Rietveld structure refinement. Ce3+ and Mn2+ co-doped NCSO phosphors exhibit blue - red dual emission under the excitation of 336 nm. The blue emission mainly comes from the 5d-4f transition of Ce3+, while the red emission belongs to the 4T1(4G)-6A1(6S) spin-forbidden transition of Mn2+. The emission spectra of NCSO: Ce3+, Mn2+ is in good agreement with the absorption spectra of chlorophyll. The ET process from Ce3+ to Mn2+ is studied and the temperature-dependent luminescence is examined to verify the thermal stability of phosphor. These results indicate that the as-obtained phosphors may have potential applications in plant growth lighting.