Lanthanide complexes are widely used in luminescent security inks due to their unique and robust photo-physical properties and they can also easily be engineered to undergo circularly polarised luminescence (CPL). However, chiral CPL signals have not yet been exploited as means in advanced security inks.1 Until our recent break-through in CPL measurement technology that enables rapid, high-throughput, security ink verification,2 the technology used to measure CPL has been somewhat stagnant.
The synthetic aspect of this project is dedicated to develop blended polymer encapsulated organic emitters and chiral Ln(III)complexes to create multi-layered unclonable QR code patterns. Novel CPL-active Ln(III) complexes with cumulative expertise based strategies to maximise gem and increase CPB (CPL brightness) will be synthesized as part of the project.
Using a commercially available polymer matrix that is already part or will be suitable to be incorporated into modern ‘plastic’ banknotes as a transparent layer a lithographically etched chiral separator can be embedded into the banknote alongside the luminescent dye formula. Therefore, using a handheld time resolved detector,3 also developed as part of this project using a novel polarized Thor labs camera, and the ‘secret etched polarizer’ (the structure of the Big Ben is perfect) in combination with a unique dye mixture formula can result in a unique fingerprint tri-color security dye encoding 3 chiroptical QR codes in one. A simple fold over of this separator unit onto the UV illuminated banknote will result in color change of the security dye that can further be changed to a third hidden color by time gating the red Europium component (unique chiral/spectral fingerprint and ms lifetime) separating it from the short lived (ns) organic green or blue fluorophores. These combined are unprecedented, resulting in 5 tiers of unclonable hidden (invisible to the naked eye) security feature. This project therefore combines polymer science, lithography and dye formulation of organic and chiral lanthanide emitters rendering it to be a truly multidisciplinary research project.
Applicants should have a first-class or upper second-class Master’s degree.
Eligibility: The position is only open to applicants from the UK for fees purposes. Early applications are strongly encouraged as the position will be filled when a suitable candidate is identified.
How To Apply: An informal expression of interest can be made by contacting Dr Robert Pal, email: [Email Address Removed].
Formal applications should be made online via Durham’s on-line application portal: https://studyatdurham.microsoftcrmportals.com/en-US/