Luminescent and colorimetric properties of the sol-gel derived mono-phase Dy3+ doped silicate-based phosphor for w-LED applications

The present work elucidates a systematic exploration of structural, morphological, and photoluminescence (PL) features of sol-gel derived Dy3+ doped sodium calcium silicate (Na2CaSiO4: NCS) phosphor. The X-ray diffraction (XRD) data indicate single-phase cubic crystal formation of NCS: Dy3+ phosphors as all the present diffraction peaks are in accordance with the standard Na2CaSiO4 data (JCPDS card No. 24-1069). The scanning electron microscopy (SEM) image of the as-synthesized NCS sample reveals irregular crystalline structures coalesced together to form micro-sized particles. The PL studies of NUV excited Dy3+ doped NCS phosphors disclose intense emission peaks at 484 and 575 nm. Dy3+ ion concentration is optimized to achieve the maximum light intensity in NCS phosphors. The concentration quenching is the consequence of energy transfer mechanism beyond 1.0 mol% (optimized) of the Dy3+ ion concentration, which was also examined in detail. The reckoned CIE coordinates (0.337, 0.346) for the optimized Dy3+:NCS phosphor located nearby standard white point coordinates, indicating the pure white light emission. Moreover, temperature-dependent luminescence studies express admirable thermal stability of as-made Dy3+:NCS phosphor as the emission intensity even at 423 K persists up to 77.26% of intensity at room temperature. Aforesaid results support the effective utilization of Dy3+ doped NCS phosphor in white LEDs. [GRAPHICS] .