One-Step Microwave Synthesis of New Hybrid Phosphor (CSSC) for White Light-Emitting Diodes

The possibility of synthesizing a new hybrid phosphor CSSC (mixture of 0.5 CaSrSiO4:Eu2+: 0.29 Ca6Sr4Si6O21Cl2:Eu2+: 0.21 Ca10Si6O21Cl2:Eu2+) using a one-step microwave synthesis method is demonstrated. The concentrations of europium and calcium in the synthesized phosphors were optimized at 1 and 10 mol. %, respectively, to achieve maximum brightness and color rendering index. The optimal conditions for the synthesis of phosphors in a microwave furnace were determined as 750 °C for 10 min. The resulting phosphor exhibited a wide luminescence spectrum that covered the entire visible region, resulting in a high color rendering index and a warm white luminescence when used as a light source. It is shown that the sol–gel method for preparing the charge mixture for the new phosphor allows for a 35% higher luminescence brightness compared to the solid-phase method, due to a more uniform distribution of the activator.