Project Description

Data counterfeiting is worldwide fraud, that has become a major concerning issue for governments, large/medium/small scale companies and consumers. An unfair and illegal competition causes critically loss of socio-economic growth of an industry or an individual, which in turn cause a serious loss for the nation as a whole. A lot of passive practices such as hologram, bar codes, QR code, watermarks and steganographic markings intaglio printing, luminescent ink, micro-lettering are being used to curb counterfeiting practices. However, most of the are difficult to realise practical on a large scale due to relatively complex identification process or verification analysis.

Afterglow/persistence luminescence is an unusual and compelling phenomenon of photon energy storage in which charge carriers are trapped in meta stable intermediate trap levels. Trap levels can be deliberately created via introducing defects or co-doping in the host lattice. Thus, we aim to develop ingenuously develop stable rare earth doped lead free and perovskite based dual level NIR excitable upconverting luminescent ink with afterglow emission in visible range (400-650 nm). Involvement of both process of up-converting luminescence (excitation depended emission) and afterglow (or also known as persistence) luminescence, provides a dual level security feature to the security ink which is tough to duplicate or imitate.