Park, Kisun Park, Minji Jang, Ho Seong Park, Ji Hun Kim, Jaekyun Cho, Younghak Han, Il Ki Byun, Dongjin Ko, Hyungduk 2024-01-19T22:34:14Z 2024-01-19T22:34:14Z 2021-09-03 2018-05-24 1616-301X https://pubs.kist.re.kr/handle/201004/121362 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. English WILEY-V C H VERLAG GMBH SOLAR-CELLS NANOPARTICLES ENHANCEMENT EFFICIENCY PLATFORM ENERGY FILMS SIO2 Highly Secure Plasmonic Encryption Keys Combined with Upconversion Luminescence Nanocrystals Article 10.1002/adfm.201800369 1 ADVANCED FUNCTIONAL MATERIALS, v.28, no.21 ADVANCED FUNCTIONAL MATERIALS 28 21 scie scopus 000434030500014 2-s2.0-85045411231 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article SOLAR-CELLS NANOPARTICLES ENHANCEMENT EFFICIENCY PLATFORM ENERGY FILMS SIO2 encryption graphene transfer plasmonic enhancement upconversion