Blue light emitting Sr2MgSi2O7:Eu2+ nanophosphor for latent fingerprint, anti-counterfeiting and near UV-LED applications

Eu2+ doped Sr2MgSi2O7:Eu2+ nanophosphors (SMSO:Eu2+ NPs) have been synthesized by using solid-state reaction method. As Eu2+ concentration increases, energy transfer (ET) between Eu2+ ions dominated attributed to dipole-dipole (d-d) interaction. Besides, temperature-dependent photoluminescence (PL) of optimized SMSO:7Eu(2+) NPs is investigated. The emission shifts towards blue with increased temperature. From the temperature-dependent emission, the activation energy, is similar to 0.40 eV. CIE coordinate is (0.1476, 0.1141) with CCT value of 3633 K. The optimized phosphor is used to detect LFPs on various surfaces. The level I-III features are clearly identified under UV 365 nm excitation. Several pores properties namely pore size, shape, number, position, type and pore inter-distance are analyzed in detail. The anti-counterfeiting results clearly showed the enhanced intensity owing to its nano-size, reduced light dispersion and increased light absorption. The overall results clearly suggest the optimized SMSO:7Eu(2+) NPs are promising luminescent platform for nUV light-emitting diode (LED) and latent fingerprint (LFP) applications.