Fabrication of flux supported SrTiO3:Eu3+ fluorescent powders: New prospective of dual mode, ink-free data security applications

Abstract

In the present paper, various fluxes assisted Eu3+ doped SrTiO3 nanophosphors were prepared via a solution combustion route. Among all fluxes, NH4F was found to be an appropriate one, which can reduce the forming temperature, improve morphology and enhance the luminescence intensity by two-fold to that of without added flux. Hence, NH4F assisted with SrTiO3:Eu3+ nanophosphor was utilized to fabricate a handy, ink-free photoluminescent writable chalk; which writes information on many complex surfaces at any time and any place. The written original information cannot be visualized upon normal light illumination; but, it was readable under UV 254 nm light. The ink-free nanophosphor-polymer matrix was fabricated via a relief printing mode as an anti-counterfeiting label. The developed templates exhibit brighter uniform fluorescence due to effective hydrogen bonding between functional groups of nanophosphors and polyvinyl alcohol. The obtained results clearly showed that the optimized nanophosphor can be used as a dual mode, ink-free fluorescence label for security applications.

Keywords

• Data security
• Photoluminescent chalk
• Security inks
• Photometric properties