Highly Secure Plasmonic Encryption Keys Combined with Upconversion Luminescence Nanocrystals. (14th April 2018)

• Record Type: Journal Article
• Authors: Park, Kisun; Park, Minji; Jang, Ho Seong; Park, Ji Hun; Kim, Jaekyun; Cho, Younghak; Han, Il Ki; Byun, Dongjin; Ko, Hyungduk
• Is Part Of: Advanced functional materials. Volume 28:Number 21(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-14
• Subjects: encryption -- graphene transfer -- plasmonic enhancement -- upconversion; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201800369
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: This study proposes a novel and highly secure encryption technology based on plasmonic‐enhanced upconversion luminescence (UCL). The technology can be realized by a disordered plasmonic nanostructure composed of a transferred metal nanoparticle–UC nanocrystals (UCNC)–metal (tMUM) film using the graphene transfer process, in which the metal nanoparticles that formed on the graphene layer are transferred using Scotch tape. The plasmonic tMUM film strongly enhances the UCL by a factor of 200 mainly because of the excitation of the gap plasmon polaritons. Meanwhile, the UCNCs in direct contact with the metal film result in luminescence quenching caused by a nonradiative process. Herein, a highly secure anti‐counterfeit film is developed, which is very hard to duplicate and cannot be reused, using two conflicting features (i.e., emission enhancement and quenching phenomena). The UCL is strongly amplified only when the first (i.e., a random metal nanoparticle array) and second (i.e., UCNCs on a Ag film) codes are very precisely overlapped as designed, thereby generating the originally designed final code. Therefore, our novel high‐level security device is expected to be easily applied to protect and identify genuine products. Abstract : A highly secure anti‐counterfeit film is developed, which is very hard to duplicate and cannot be reused, using two conflicting features (i.e., emission enhancement and quenching phenomena). This security film can be implemented on various substrates, including a flexible substrate, and it is highly scalable regardless of the pattern type and size.