Reported by Roopak Goswami
Guwahati: Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a new light-emitting nanomaterial that could help combat fake currency, forged documents, and counterfeit products through advanced security markings that are extremely difficult to copy.
The research team has created tiny glowing crystals, known as perovskite nanocrystals, that can produce highly specific light patterns that are invisible to the naked eye and impossible to replicate using conventional printing or imaging techniques.
The study was carried out by Saikat Bhaumik and P.K. Giri from IIT Guwahati’s Department of Physics, along with research scholars Latika Juneja and Garima Choudhary. The findings were published in the international journal Advanced Optical Materials.
Counterfeiting has become a growing global problem, affecting sectors such as banking, pharmaceuticals, electronics, luxury goods, and identity documentation.
Traditional security features like QR codes, holograms, and watermarks are increasingly being copied using modern technology.
To tackle this, the IIT Guwahati team developed nanocrystals that emit very pure and bright colours with unique optical signatures. These materials are thousands of times smaller than a human hair and can be used to create hidden security patterns.
One major problem with such materials is that they usually degrade when exposed to heat, moisture, or chemicals. To overcome this, the researchers designed a special double-layer protective coating that keeps the nanocrystals stable while preserving their glowing properties.
Using a direct laser-writing technique, the team then created microscopic security patterns without relying on traditional printing masks. The result is highly detailed and complex patterns capable of storing hidden information.
Explaining the technology, Saikat Bhaumik said the material behaves differently from ordinary security labels.
“Unlike normal labels that always show the same mark, these materials react differently to heat and chemicals. An invisible fluorescent pattern can disappear when heated and reappear after chemical treatment,” he said.
This means counterfeiters would not only have to copy the visible pattern but also reproduce how the material reacts under specific conditions, making duplication extremely difficult.
The researchers have named this concept “4D anti-counterfeiting.”
Beyond security applications, the technology may also be useful in developing next-generation micro-LED displays for smartphones, wearable devices, and augmented reality systems.
The team said the technology could eventually be used in currency notes, passports, identity cards, luxury products, and branded goods for advanced authentication and secure information storage.
However, the researchers clarified that the work is currently at the laboratory stage and requires further testing before commercial use.