Thermally stable Mn2+‐activated zinc silicate nanophosphor for speedy recognition of high‐contrast latent fingermarks

Abstract Crystalline divalent manganese‐activated zinc orthosilicate (Zn 2 SiO 4 :Mn 2+ ) nanophosphor has been synthesized via the solution‐based sol–gel process. Structural, morphological, and photoluminescence (PL) properties were explored. X‐ray diffraction pattern confirms the crystalline hexagonal structure of the single‐phase Zn 2 SiO 4 powder. The size and shape of Zn 2 SiO 4 powder were analyzed using micrographs, which implies that the prepared phosphor particles are in the nano range. PL spectra have been recorded as a function of Mn 2+ dopant concentration. A dominant green (∼526 nm) emission broad peak was observed owing to the characteristic ( 4 T 1 → 6 A 1 ) transition of Mn 2+ ion under UV/blue excitation. The green emission (∼526 nm) intensity depends upon the doping concentration of Mn 2+ ion, and it is found to be optimum for 2.0 mol%, after that quenching phenomenon was registered. The CIE color coordinate of Zn 2 SiO 4 :Mn 2+ lies in the bright green region under UV excitation with 94.3% color purity. Real‐time experiments have been carried out for speedy development of high‐contrast fingermarks using Zn 2 SiO 4 nanophosphor on various porous and nonporous substrates.