Optoelectronic investigation of pyrosilicate based Y2Si2O7:Dy3+nanophosphor: A prospective white light emitter for NUV based-wLEDs

We report on development and properties of Dy3+ 3 + doped Y2Si2O7 2 Si 2 O 7 (YPS) phosphor, a key development in efficient, sustainable lighting via phosphor converted white light emitting diodes (pc-wLEDs). Using gel-combustion method, we synthesized a series of Y2-xSi2O7:xDy3+ 2-x Si 2 O 7 :xDy 3 + (x = 1-8 mol %) phosphors. The prepared samples were characterized for their structure, morphology and elemental composition using X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) respectively. Diffraction exploration verified triclinic structure and phase purity of fabricated samples. TEM image displayed particle agglomeration with nearly spherical structures. Optical parameters were assessed through diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectra analysis. On 352 nm excitation, distinct luminous peaks from Dy3+ 3 + ions, analogous to 4F9/2-*6HM F 9/2-* 6 H M (M = 15/2, 13/2, and 11/2) transitions, were observed. Particularly, intense emission at 571 nm resulted from the 4F9/2 F 9/2-* 6 H 13/2 . The optimal amount of Dy3+ 3 + was determined to be 5 mol %, with concentration quenching attributed to quadrupole-quadrupole interaction. Y1.95Si2O7:5 1.95 Si 2 O 7 :5 mol % Dy3+ 3 + phosphor possessed activation energy of 0.2503 eV and demonstrates good thermal stability. Thus, these results indicate that the synthesized Y2Si2O7:Dy3+ 2 Si 2 O 7 :Dy 3 + phosphors are well suited for white light applications.