Site occupation and energy transfer of Ce3+-Activated oxynitride Lu4SiAlO8N with broad-cyan-light-emitting property used for WLEDs

The systems of Si-Al-O-N originated from the outstanding nitrogen ceramic of Si 3 N 4 have received considerable attention due to their significant luminescence properties . In this work, to explore its potential in the full-spectrum lighting applications, a novel oxynitride based phosphor Lu 4 SiAlO 8 N: Ce 3+ was investigated in detail by using the Rietveld refinement , DFT calculations, photoluminescent (PL) and time-resolved PL (TRPL) spectra. The results indicate that Lu 4 SiAlO 8 N performs a tight host lattice formed by the edge-sharing LuO 6 polyhedrons and (Si, Al) (O, N) 4 tetrahedrons; the multiple crystallographic Lu 3+ sites in the host lattice contribute to the broad emission band. Under the near ultraviolet (NUV) light excitation, Lu 4 SiAlO 8 N: Ce 3+ emits a bright cyan light peaked at 470 nm, and its full width at half maximum (FWHM) can reach 120 nm, which well replenishes the “cyan cavity”. Moreover, the energy transfer between the multiple luminescent centers was verified through the TRPL spectra . The temperature-dependent spectra of Lu 4 SiAlO 8 N: Ce 3+ was measured to prove its acceptably thermal stability. All the results indicate the Lu 4 SiAlO 8 N: Ce 3+ to be a promising candidate for the application in WLEDs .