A Plasmonic Platform with Disordered Array of Metal Nanoparticles for Three‐Order Enhanced Upconversion Luminescence and Highly Sensitive Near‐Infrared Photodetector

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A novel, efficient, cost-effective, and high-level security performance anticounterfeit device achieved by plasmonic-enhanced upconversion luminescence (UCL) is demonstrated. The plasmonic architecture consists of the randomly dispersed Ag nanowires (AgNWs) network, upconversion nanoparticles (UCNPs) monolayer, and metal film, in which the UCL is enhanced by a few tens, compared to reference sample, becuase the plasmonic modes lead to the concentration of the incident near infrared (NIR) light in the UCNPs monolayer. In the configuration, both the localized surface plasmons (LSPs) around the metallic nanostructures and gap plasmon polaritons (GPPs) confined in the UCNPs monolayer, significantly contribute to the UCL enhancement. The UCL enhancement mechanism resulting from enhanced NIR absorption, boosted internal quantum process, and formation of strong plasmonic hot spots in the plasmonic architecture is analyzed theoretically and numerically. More interestingly, a proof-of-concept anticounterfeit device using the plasmonic-enhanced UCL is proposed, through which a nonreusable and high-level cost-effective security device protecting the genuine products is realized.S P n .[34] The latter is due to the typical linear decay of the excited population, whereas the nonlinear process is led by the two-photon process-intervened energy transfer. [28,[35][36][37] The pNUM configuration is observed to exhibit the threshold for the linear process at a lower excitation power than that for other architectures, indicating that the second excited level in Adv. Funct. Mater. 2016, 26, 7836-7846 www.afm-journal.de www.MaterialsViews.com full paper 7838 wileyonlinelibrary.com

Section: Resultsmentioning

confidence: 58%

Section: Resultsmentioning

confidence: 99%

“…This abrupt decrease indicates that the radiative decay rate is more effectively boosted by the internal quantum processes in the pNUM configuration [27,28,[35][36][37] than the reference. [27,28,[35][36][37] We found that all the processes and factors are noticeably enhanced in the pNUM compared to in UG. [27,28,[35][36][37] A strong UCL enhancement results from four different factors such as absorption efficiency enhancement (f), faster energy transfer rate between the donor and acceptor levels (k 1 ), increase in Γ r , and increase in the fraction of the plasmonic resonance-affected UCNPs mono layer (ξ).…”

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Plasmonic Nanowire‐Enhanced Upconversion Luminescence for Anticounterfeit Devices

Park

Jung

Kwon

et al. 2016

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Highly Secure Plasmonic Encryption Keys Combined with Upconversion Luminescence Nanocrystals

Park

Jang

et al. 2018

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.

Plasmonic Photonic Crystals Induced Two‐Order Fluorescence Enhancement of Blue Perovskite Nanocrystals and Its Application for High‐Performance Flexible Ultraviolet Photodetectors

Zhou

et al. 2018

110

Blue perovskite nanocrystal (NC) can be an ideal kind of material for UV photodetectors owing to its excellent band gap, however, limited by its photoacoustic process. Here, the luminescent enhancement of CsPbCl 3 NCs is first explored by coupling with Ag plasmon and photonic crystals. Consistently with the theoretical simulation, when the plasmon peak of Ag film and photonic stop band of polymethyl methacrylate opal photonic crystals (OPCs) match well with the emission peak of blue CsPbCl 3 NCs, the fluorescence enhancements of about 50-fold and 20-fold are obtained, owing to the collective effect of the excitation and emission field enhancement. Then, through the combination of surface plasmon and photonic crystal effects, the luminescent intensity of CsPbCl 3 NCs in CsPbCl 3 /Ag/OPCs hybrids is boosted more than 150-fold with the estimated emission efficiency of 51.5%. Furthermore, the high performance flexible UV photodetector is constructed employing CsPbCl 3 /Ag/OPCs hybrids, demonstrating extremely low dark current of 10 -11 A, high detectivity of 9 × 10 14 Jones, short response time of 28 ms/31 ms, and narrow response line width of 30 nm, which is much better than the commercial silicon photodetectors. This work provides a helpful approach to improve the luminescence/performance of perovskite NCs and UV photodetectors.