Cerium (III) ion doped-Gd2-xSi2O7 phosphor material for blue-LEDs and Bio-marker for latent fingerprint detection

Blue light-emitting materials Gd_2-xSi₂O₇:xCe³⁺ (0.02 ≤ x ≤ 0.12) were synthesised hydrothermally followed by calcination. The selected phosphors' phase determination, morphology and luminescence properties were identified using structural and spectrophotometric investigation, respectively. The prepared samples were single-phase and the crystal structure was determined to be orthorhombic with the help of Rietveld refinement. Furthermore, the average diameter of the pores in these phosphors is determined to be 15.56 nm with the help of BET analysis. The zoomed part induced by concentration XRD patterns of the Ce³⁺ samples of Gd_2-xSi₂O₇ indicates that the diffraction pattern exhibits a consistent shift towards a lower value of 2θ as the concentration of Ce³⁺ ion rises. Blue light emission is observed in Gd_2-xSi₂O₇:xCe³⁺ samples when excited at 370 nm by Near-UV radiation. The energy transfer among the activator ions in the Gd_2-xSi₂O₇ matrix is consistent with a quadrupolar-quadrupolar interaction. Two possible cationic locations for the Ce³⁺ ions in the host lattice can be explained with the help of biexponential fitting behaviour. The produced samples have potential applications in designing phosphor-converted blue light, LED-B1 (Color purity = 94.73 %), LED-V1 and LED-RGB1(Color purity = 94.72 %). The blue-emitting phosphors were also utilised to identify latent fingerprints on smooth surfaces. The level 1,2 and 3 fingermarks could be easily seen under UV light and exhibited excellent contrast with the background.