Exploring the potential of KSr6ScSi4O16:Eu2+ phosphors for full-spectrum light emitting diodes

To realize full-spectrum illumination systems for daily applications, the development of cyan-emitting phosphors capable of addressing the spectral deficiency in the 480-520 nm region (between blue and green emissions) has emerged as a critical research frontier in solid-state lighting technology. In this investigation, a scandium silicate phosphor, KSr 6 ScSi 4 O 16 :Eu 2+ , was initially synthesized via a high-temperature solid-state reaction under a reducing atmosphere. The target compounds crystallize in an orthorhombic system with a centrosymmetric space group of Pnma (No. 62). KSr 6 ScSi 4 O 16 :2 mol%Eu 2+ shows asymmetric broadband mainly at 481 nm under excitation of 359 nm. Based on Gaussian fitting and Van Uitert's equation, the Eu 2+ ion was confirmed to occupy two different coordination environments of Sr 2+ , producing two different luminescent centers at 477 nm and 528 nm. The optimal doping concentration of KSr 6 ScSi 4 O 16 : x Eu 2+ cyan phosphors was founded to be 2 mol%. Within the temperature range of 300 to 480 K, CIE coordinates remain stable during the heating process, and an activation energy of 0.35 eV has been determined. The color rendering index ( R a ) of the full spectrum WLED produced by KSr 6 ScSi 4 O 16 :Eu 2+ , reached 92.5, which is higher than the WLED packaged with commercial powder, effectively supplementing the cyan light component and closer to the full-spectrum lighting LEDs.