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Vodnik, Vesna V., Dušan K. Božanić, Nataša Bibić, Zoran V. Šaponjić i Jovan M. Nedeljković. "Optical Properties of Shaped Silver Nanoparticles". Journal of Nanoscience and Nanotechnology 8, nr 7 (1.07.2008): 3511–15. http://dx.doi.org/10.1166/jnn.2008.144.
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The influence of shape and dielectric property of surrounding media on surface plasmon absorption band of silver nanoparticles was studied. Spherical silver nanoparticles (d = 5.6 nm) synthesized in water using NaBH4 as a reducing agent are transferred in non-polar solvent (chloroform) with phase-transfer reagent oleylamine. The absorption spectrum of oleylamine-capped silver nanoparticles dispersed in chloroform shows a strong surface plasmon resonance band that is 19 nm red-shifted compared to unmodified particles in water. The values for peak position and corresponding half widths are compared with theoretical calculations based on Mie theory. Prismatic and plate-like silver nanoparticles were synthesized in water using trisodium citrate as a reducing agent and cetyltrimethylammonium bromide as stabilizer. Due to structural anisotropy of prismatic and plate-like silver nanoparticles three surface plasmon resonance bands were observed in absorption spectrum. Nanocomposites consisting of non-spherical silver nanoparticles and polyvinyl alcohol exhibit different optical properties compared to water colloid. Instead of three surface plasmon bands, nanocomposite film has only one peak at 460 nm. Reason for appearance of single surface plasmon resonance band in nanocomposite film was discussed according to Maxwell-Garnet theory.
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Yuan, Zong Heng, Dong Dong Zhu i Peng Wang. "The Study of Nano Optical Antenna Based on Surface Plasmon Resonance". Applied Mechanics and Materials 110-116 (październik 2011): 3825–30. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.3825.
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The strong local property of surface plasmon polaritons can break through the diffraction limit, and reduce the propagation of corner scattering on nanoscale. The nanoantenna structure based on the plasmon resonant effect can collect the light energy effectively, and the local field enhancement effects of the structure have extensive application prospect. The field distribution and field enhancement effects of optical antenna under nanoscale are calculated with finite-difference time-domain (FDTD) method. Several different structures of nanooptical antenna are studied, and their enhancement properties are compared in this paper.
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LEE, YIH HONG, POLAVARAPU LAKSHMINARAYANA, CUIFENG JIANG, PEIYAN YUAN i QING-HUA XU. "RECENT ADVANCES IN METAL-ENHANCED OPTICAL PROPERTIES". COSMOS 06, nr 02 (grudzień 2010): 167–95. http://dx.doi.org/10.1142/s0219607710000619.
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Noble metal nanoparticles exhibit strong surface plasmon resonance (SPR) and have been utilized in many chemical, biological and electronic applications. Recent advances on metal-enhanced optical properties demonstrated that the quantum yield and photo-stability of the fluorophores can be significantly enhanced when they are in the proximity of the metal surface, that will benefit many fluorescence-based applications. In this review article we first discuss the fundamental concepts of metal-enhanced optical properties and the recent achievements of metal-enhanced fluorescence of organic fluorophores and quantum dots, as well as metal-enhanced phosphorescence of organic molecules and upconversion nanoparticles that have long life times. Finally, we present recent applications of metal-enhanced optical properties in biosensing and bioassays, photodynamic therapy and optoelectronics.
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Benoit, J. M., K. Chevrier, C. Symonds i J. Bellessa. "Strong coupling for bifunctionality in organic systems". Applied Physics Letters 121, nr 18 (31.10.2022): 181101. http://dx.doi.org/10.1063/5.0116184.
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In this paper, we exploit the strong light–matter coupling to hybridize two materials for bifunctionality properties. The strong coupling has been achieved between a surface plasmon and two organic emitters: a J-aggregate cyanine dye, known for its high absorption and emission properties and a photochromic material in which absorption can be optically switched on and off. The optical properties are drastically modified between the activated and deactivated forms of the photochromic material coupled to the cyanine dye. In particular, the emission of the structure can be energy shifted by several hundreds of meV providing a way to build a tunable emission system. This system also reveals its potential for modifying the fluorescence of photochromes thanks to light–matter interaction instead of functionalization using covalent bonding.
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Tang, Yuankai, Xiantong Yu, Haifeng Pan, Jinquan Chen, Benjamin Audit, Françoise Argoul, Sanjun Zhang i Jianhua Xu. "Numerical Study of Novel Ratiometric Sensors Based on Plasmon–Exciton Coupling". Applied Spectroscopy 71, nr 10 (16.05.2017): 2377–84. http://dx.doi.org/10.1177/0003702817706979.
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We numerically studied the optical properties of spherical nanostructures made of an emitter core coated by a silver shell through the generalized Mie theory. When there is a strong coupling between the localized surface plasmon in the metallic shell and the emitter exciton in the core, the extinction spectra exhibit two peaks. Upon adsorption of analytes on these core-shell nanostructures, the intensities of the two peaks change with opposite trends. This property makes them potential sensitive ratiometric sensors. Molecule adsorption on these nanostructures can be quantified through a very simple optical configuration likely resulting in a much faster acquisition time compared with systems based on the traditional metal nanoparticle surface plasmon resonance (SPR) biosensors.
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Kim, Wan-Joong, JaeTae Seo, Chil Seong Ah, Jasmine Austin, Shanghee Kim, Ansoon Kim, Gun Yong Sung i Wan Soo Yun. "Colorimetric Analysis on Flocculation of Bioinspired Au Self-Assembly for Biophotonic Application". Journal of Nanomaterials 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/261261.
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Gold nanoparticles exhibited strong surface plasmon absorption and couplings between neighboring particles within bioactivated self-assembly modified their optical properties. Colorimetric analysis on the optical modification of surface plasmon resoanance (SPR) shift and flocculation parameter functionalized bioinspired gold assembly for biophotonic application. The physical origin of bioinspired gold aggregation-induced shifting, decreasing, or broadening of the plasmon absorption spectra could be explained in terms of dynamic depolarization, collisional damping, and shadowing effects.
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Bitton, Ora, Satyendra Nath Gupta i Gilad Haran. "Quantum dot plasmonics: from weak to strong coupling". Nanophotonics 8, nr 4 (23.02.2019): 559–75. http://dx.doi.org/10.1515/nanoph-2018-0218.
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AbstractThe complementary optical properties of surface plasmon excitations of metal nanostructures and long-lived excitations of semiconductor quantum dots (QDs) make them excellent candidates for studies of optical coupling at the nanoscale level. Plasmonic devices confine light to nanometer-sized regions of space, which turns them into effective cavities for quantum emitters. QDs possess large oscillator strengths and high photostability, making them useful for studies down to the single-particle level. Depending on structure and energy scales, QD excitons and surface plasmons (SPs) can couple either weakly or strongly, resulting in different unique optical properties. While in the weak coupling regime plasmonic cavities (PCs) mostly enhance the radiative rate of an emitter, in the strong coupling regime the energy level of the two systems mix together, forming coupled matter-light states. The interaction of QD excitons with PCs has been widely investigated experimentally as well as theoretically, with an eye on potential applications ranging from sensing to quantum information technology. In this review we provide a comprehensive introduction to this exciting field of current research, and an overview of studies of QD-plasmon systems in the weak and strong coupling regimes.
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Yi, Zao, Xin Li, Xibin Xu, Xifang Chen, Xin Ye, Yong Yi, Tao Duan, Yongjian Tang, Jiangwei Liu i Yougen Yi. "Nanostrip-Induced High Tunability Multipolar Fano Resonances in a Au Ring-Strip Nanosystem". Nanomaterials 8, nr 8 (25.07.2018): 568. http://dx.doi.org/10.3390/nano8080568.
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Surface plasmon resonances of a Au ring-strip nanosystem with tunable multipolar Fano resonances have been investigated based on the finite-difference time-domain (FDTD) method. Abundant plasmon properties of a Au ring-strip nanosystem can be obtained on the basis of the unique electronic properties of different geometry parameters. In our research models, these multipolar Fano resonances are induced and can be tuned independently by changing the geometry parameters of the Au ring-strip nanosystem. Complex electric field distributions excited by the Au ring-strip nanosystem provide possibility to form dark plasmonic modes. Multipolar Fano resonances display strong light extinction in the Au ring-strip nanosystem, which can offer a new approach for an optical tunable filter, optical switching, and advanced biosensing.
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Halas, Naomi. "Playing with Plasmons: Tuning the Optical Resonant Properties of Metallic Nanoshells". MRS Bulletin 30, nr 5 (maj 2005): 362–67. http://dx.doi.org/10.1557/mrs2005.99.
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AbstractNanoshells, concentric nanoparticles consisting of a dielectric core and a metallic shell, are simple spherical nanostructures with unique, geometrically tunable optical resonances. As with all metallic nanostructures, their optical properties are controlled by the collective electronic resonance, or plasmon resonance, of the constituent metal, typically silver or gold. In striking contrast to the resonant properties of solid metallic nanostructures, which exhibit only a weak tunability with size or aspect ratio, the optical resonance of a nanoshell is extraordinarily sensitive to the inner and outer dimensions of the metallic shell layer. The underlying reason for this lies beyond classical electromagnetic theory, where plasmon-resonant nanoparticles follow a mesoscale analogue of molecular orbital theory, hybridizing in precisely the same manner as the individual atomic wave functions in simple molecules. This plasmon hybridization picture provides an essential “design rule” for metallic nanostructures that can allow us to effectively predict their optical resonant properties. Such a systematic control of the far-field optical resonances of metallic nanostructures is accomplished simultaneously with control of the field at the surface of the nanostructure. The nanoshell geometry is ideal for tuning and optimizing the near-field response as a stand-alone surface-enhanced Raman spectroscopy (SERS) nanosensor substrate and as a surface-plasmon-resonant nanosensor.Tuning the plasmon resonance of nanoshells into the near-infrared region of the spectrum has enabled a variety of biomedical applications that exploit the strong optical contrast available with nanoshells in a spectral region where blood and tissue are optimally transparent.
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Nan, Ya Li, Shang Xu, Fei Liu i Jian Feng Zhou. "Gas Phase Synthesis of Vanadium Oxide Nanoparticle Films with Temperature Controlled Surface Plasmon Resonance Properties". Applied Mechanics and Materials 548-549 (kwiecień 2014): 152–57. http://dx.doi.org/10.4028/www.scientific.net/amm.548-549.152.
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Vanadium oxide nanoparticles were synthesized with controlled size and dispersity by gas phase cluster beam deposition. The composition of the nanoparticle film is dominated with VO2 nanoparticles. The VO2 nanoparticles undergo a phase transition between the room temperature monoclinic insulator phase and the higher temperature rutile metal phase. In the metallic phase, the VO2 nanoparticles exhibit a strong surface plasmon resonance in the near-IR region from 900nm to the 2000nm, which generates a large enhancement on the extinction coefficient. This plasmon resonance is thermally controlled by the VO2 MIT and can be used to improve the optical switching characteristics of VO2 based devices in the near-IR region.
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Ding, Yanyue, Jian Chen, Gan Xu, Fei Liu i Min Han. "Evolution and Tailoring of DUV Plasmonic Properties in Al Nanoparticle Arrays by UV Irradiation". Journal of Nanomaterials 2018 (9.09.2018): 1–6. http://dx.doi.org/10.1155/2018/8798274.
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Ultraviolet irradiation was used to tailor the surface plasmon band of the densely distributed aluminium nanoparticle arrays fabricated by gas-phase deposition. We showed that the broad surface plasmon resonance band of the as-prepared sample could be tuned to a sharp and strong resonance band in the deep ultraviolet optical range, with a large blue shift of the peak wavelength. The evolution of the surface plasmon resonance properties was attributed to the ultraviolet irradiation-improved surface oxidation of the nanoparticles, which eliminated the near-field couplings between the closely spaced nanoparticles by increasing their interspacing.
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Kolmychek, Irina A., Ksenia A. Lazareva, Evgeniy A. Mamonov, Evgenii V. Skorokhodov, Maksim V. Sapozhnikov, Valery G. Golubev i Tatiana V. Murzina. "Size Effects in Optical and Magneto-Optical Response of Opal-Cobalt Heterostructures". Materials 14, nr 13 (22.06.2021): 3481. http://dx.doi.org/10.3390/ma14133481.
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Search for new types of efficient magnetoplasmonic structures that combine high transparency with strong magneto-optical (MO) activity is an actual problem. Here, we demonstrate that composite heterostructures based on thin perfectly-arranged opal films and a perforated cobalt nanolayer meet these requirements. Anomalous transmission appears due to periodic perforation of Co consistent with the regular set of voids between opal spheres, while resonantly enhanced MO response involves the effects of surface plasmon-polariton (SPP) excitation at opal/Co interface or those associated with photonic band gap (PBG) in opal photonic crrystals. We observed the enhancement of the MO effect of up to 0.6% in the spectral vicinity of the SPP excitation, and several times less strong effect close to the PBG, while the combined appearance of PBG and SPP decreases the resultant MO response. Observed resonant magneto-optical properties of opal/Co heterostructures show that they can be treated as functional self-assembled magnetoplasmonic crystals with resonantly enhanced and controllable MO effect.
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Modric-Sahbazovic, A., M. Novakovic, E. Schmidt, N. Bibic, I. Gazdic, C. Ronning i Z. Rakocevic. "Thermal annealing of Ag implanted silicon: Relationship between structural and optical properties". Science of Sintering 52, nr 2 (2020): 207–17. http://dx.doi.org/10.2298/sos2002207m.
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Low energy Ag ions were implanted into silicon and annealed at different temperatures in order to generate plasmonic active silicon hybrids. It was found that as the ion fluence of irradiation was increased, a monotonic decrease in the absorption spectra in the ultraviolet region occurs, due to amorphization and macrostructuring of the Si surface. At the same time, the optical spectra are characterized by a strong band after implantation presenting the contribution of the surface plasmon resonance (SPR) of Ag nanoparticles. After heat treatment at 500 and 600?C, the SPR peak shifts to lower wavelengths, as compared to as implanted samples, whereas the plasmon position shifts to higher wavelengths for annealing at 700?C. This observation can be explained by either an out-diffusion of Ag or by stress relaxation and recrystallization of silicon.
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Ohon, Natalia, Tetiana Bulavinets, Iryna Yaremchuk i Rostyslav Lesyuk. "Plasmon-Exciton Interaction in Perspective Hetero-Systems". East European Journal of Physics, nr 4 (6.12.2022): 6–22. http://dx.doi.org/10.26565/2312-4334-2022-4-01.
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Surface plasmons and excitons have been widely studied experimentally and theoretically for various material systems. However, a number of aspects require further deeper study and understanding, among which the connection of these quasi-particles occupies an important place. New physical effects arise when plasmons and excitons in nanostructures begin to be localized at certain small distances, as a result, we can talk about their coupling. Complex systems containing the excitation of plasmons and excitons, as well as their coupling, show interesting optical properties that they cannot exhibit individually. In this type of system, the plasmon enhances the coupling between the system and the external field, and the exciton controls certain spectral properties, which opens up new possibilities for tuning their optical response. The transferred energy between plasmons and excitons becomes an important factor affecting their interaction when the resonance frequency of the localized plasmon is very close to the molecular energy transition frequency. Two types of coupling can occur depending on the ratio between the strength of the coupling and the energy losses of individual components in the system, namely strong and weak. In addition to the mutual coupling between the plasmon and the exciton, their different linewidths and ability to couple to an external field provide a variety of means to tune the optical properties of hybrid systems. Thus, it enables precise control of light at the nanometer scale, opening up possibilities for new electronics and photonics applications. In this review, we highlight the features of weak and strong modes of plasmon-exciton coupling, modern trends, and perspectives in the study of hetero-systems semiconductor–metal, metal–2D material, semiconductor–molecule, etc. Semiconductor-metal hybrid nanostructures open up exciting opportunities for the study of quantum phenomena, optical processes, and multiparticle interactions and confidently lead to application in new photonics devices.
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Rajesh, Desapogu, M. Mahendar i C. S. Sunandana. "Effect of Etching on the Optical, Morphological Properties of Ag Thin Films for SERS Active Substrates". Journal of Chemistry 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/285431.
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Structural, optical, and morphological properties of Ag thin films before and after etching were investigated by using X-ray diffraction, UV-Vis spectrophotometer, and field emission scanning electron microscopy (FESEM). The HNO3roughened Ag thin films exhibit excellent enhancement features and better stability than pure Ag thin films. Further, the Ag nanostructures are covered with Rhodamine 6G (Rh6G) and then tested with surface enhanced raman spectroscopy (SERS) for active substrates. Etched Ag films were found to exhibit a strong SERS effect and excellent thermal stability. Hence, the present method is found to be useful in the development of plasmon-based analytical devices, especially SERS-based biosensors.
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Joy, Soumitra Roy, Hao Yu i Pinaki Mazumder. "Properties of spoof plasmon in thin structures". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 474, nr 2220 (grudzień 2018): 20180205. http://dx.doi.org/10.1098/rspa.2018.0205.
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Spoof surface plasmon polariton (SSPP) is an exotic electromagnetic state that confines light at a subwavelength scale at a design-specific frequency. It has been known for a while that spoof plasmon mode can exist in planar, thin structures with dispersion properties similar to that of its wide three-dimensional structure counterpart. We, however, have shown that spoof plasmons in thin structures possess some unique properties that remain unexplored. Our analysis reveals that the field interior to SSPP waveguide can achieve an exceptional hyperbolic spatial dependence, which can explain why spoof plasma resonance incurs red-shift with the reduction of the waveguide thickness, whereas common wisdom suggests frequency blue-shift of a resonant structure with its size reduction. In addition, we show that strong confinement can be achieved over a wide band in thin spoof plasmon structure, ranging from the spoof plasma frequency up to a lower frequency considerably away from the resonant point. The nature of lateral confinement in thin SSPP structures may enable interesting applications involving fast modulation rate due to enhanced sensitivity of optical modes without compromising modal confinement.
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Zhao, Yi-Xin, Hao-Sen Kang, Wen-Qin Zhao, You-Long Chen, Liang Ma, Si-Jing Ding, Xiang-Bai Chen i Qu-Quan Wang. "Dual Plasmon Resonances and Tunable Electric Field in Structure-Adjustable Au Nanoflowers for Improved SERS and Photocatalysis". Nanomaterials 11, nr 9 (25.08.2021): 2176. http://dx.doi.org/10.3390/nano11092176.
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Flower-like metallic nanocrystals have shown great potential in the fields of nanophononics and energy conversion owing to their unique optical properties and particular structures. Herein, colloid Au nanoflowers with different numbers of petals were prepared by a steerable template process. The structure-adjustable Au nanoflowers possessed double plasmon resonances, tunable electric fields, and greatly enhanced SERS and photocatalytic activity. In the extinction spectra, Au nanoflowers had a strong electric dipole resonance located around 530 to 550 nm. Meanwhile, a longitudinal plasmon resonance (730~760 nm) was obtained when the number of petals of Au nanoflowers increased to two or more. Numerical simulations verified that the strong electric fields of Au nanoflowers were located at the interface between the Au nanosphere and Au nanopetals, caused by the strong plasmon coupling. They could be further tuned by adding more Au nanopetals. Meanwhile, much stronger electric fields of Au nanoflowers with two or more petals were identified under longitudinal plasmon excitation. With these characteristics, Au nanoflowers showed excellent SERS and photocatalytic performances, which were highly dependent on the number of petals. Four-petal Au nanoflowers possessed the highest SERS activity on detecting Rhodamine B (excited both at 532 and 785 nm) and the strongest photocatalytic activity toward photodegrading methylene blue under visible light irradiation, caused by the strong multi-interfacial plasmon coupling and longitudinal plasmon resonance.
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Rigon, Michele, Valentina Paolucci, Marco Sturaro, Seyed Mahmoud Emamjomeh, Carlo Cantalini i Alessandro Martucci. "Effect of Pt Nanoparticles on the Plasmonic and Chemoresistive Gas Sensing Properties of ZnO:Ga Film". Proceedings 2, nr 13 (30.11.2018): 997. http://dx.doi.org/10.3390/proceedings2130997.
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In this paper, we used gallium doped zinc oxide (GZO) nanocrystals as novel plasmonic and chemoresistive sensors for the detection of hazardous gases including hydrogen (H2) and nitrogen dioxide (NO2). GZO nanocrystals with a tunable surface plasmon resonance in the near infrared are obtained using a colloidal heat-up synthesis. Thanks to the strong sensitivity of the plasmon resonances to chemical and electrical changes occurring at the surface of the nanocrystals, such optical features can be used to detect the presence of toxic gases. The same material can be used also as chemoresistive sensors. The effect of Pt nanoparticles (NPs), a well-known catalyst for H2 splitting, have been studied both for the optical and chemoresistive gas response. Both thermal and blue-light (λ = 430 nm) activation were investigated.
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Chanana, Munish, i Luis M. Liz-Marzán. "Coating matters: the influence of coating materials on the optical properties of gold nanoparticles". Nanophotonics 1, nr 3-4 (1.12.2012): 199–220. http://dx.doi.org/10.1515/nanoph-2012-0008.
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AbstractAn essential element in the synthesis of nanomaterials based on gold nanoparticles comprises the control over parameters such as size, shape and composition, due to their strong influence on the properties of the particles. However, it is the coating material which often plays the primary role in tuning the size, morphology, and even plasmon resonance wavelength or mode multiplicity, as well as colloidal stability and functional versatility, ultimately determining the physical, chemical, optical, electronic and catalytic properties of the nanoparticles. Therefore, it is utterly important to select the adequate wet chemistry synthetic approach with the most suitable coating material for the preparation of gold nanoparticles with the desired requirements. Within this context, this review is focused on describing various types of organic and inorganic coating materials for gold nanoparticles that may notably affect their optical properties by either directly influencing the synthesis procedure or by changing their chemical and physical properties upon post-synthetic modifications, such that they exhibit novel and useful optical properties.
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Mennucci, Carlo, Debasree Chowdhury, Giacomo Manzato, Matteo Barelli, Roberto Chittofrati, Christian Martella i Francesco Buatier de Mongeot. "Large-area flexible nanostripe electrodes featuring plasmon hybridization engineering". Nano Research 14, nr 3 (21.10.2020): 858–67. http://dx.doi.org/10.1007/s12274-020-3125-x.
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AbstractMultifunctional flexible Au electrodes based on one-dimensional (1D) arrays of plasmonic gratings are nanofabricated over large areas with an engineered variant of laser interference lithography optimized for low-cost transparent templates. Au nanostripe (NS) arrays achieve sheet resistance in the order of 20 Ohm/square on large areas (∼ cm2) and are characterized by a strong and dichroic plasmonic response which can be easily tuned across the visible (VIS) to near-infrared (NIR) spectral range by tailoring their cross-sectional morphology. Stacking vertically a second nanostripe, separated by a nanometer scale dielectric gap, we form near-field coupled Au/SiO2/Au dimers which feature hybridization of their localized plasmon resonances, strong local field-enhancements and a redshift of the resonance towards the NIR range. The possibility to combine excellent transport properties and optical transparency on the same plasmonic metasurface template is appealing in applications where low-energy photon management is mandatory like e.g., in plasmon enhanced spectroscopies or in photon harvesting for ultrathin photovoltaic devices. The remarkable lateral order of the plasmonic NS gratings provides an additional degree of freedom for tailoring the optical response of the multifunctional electrodes via the excitation of surface lattice resonances, a Fano-like coupling between the broad localised plasmonic resonances and the collective sharp Rayleigh modes.
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Spitaleri, Luca, Chiara M. A. Gangemi, Roberto Purrello, Giuseppe Nicotra, Giuseppe Trusso Sfrazzetto, Girolamo Casella, Maurizio Casarin i Antonino Gulino. "Covalently Conjugated Gold–Porphyrin Nanostructures". Nanomaterials 10, nr 9 (21.08.2020): 1644. http://dx.doi.org/10.3390/nano10091644.
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Gold nanoparticles show important electronic and optical properties, owing to their size, shape, and electronic structures. Indeed, gold nanoparticles containing no more than 30–40 atoms are only luminescent, while nanometer-sized gold nanoparticles only show surface plasmon resonance. Therefore, it appears that gold nanoparticles can alternatively be luminescent or plasmonic and this represents a severe restriction for their use as optical material. The aim of our study was the fabrication of nanoscale assembly of Au nanoparticles with bi-functional porphyrin molecules that work as bridges between different gold nanoparticles. This functional architecture not only exhibits a strong surface plasmon, due to the Au nanoparticles, but also a strong luminescence signal due to porphyrin molecules, thus, behaving as an artificial organized plasmonic and fluorescent network. Mutual Au nanoparticles–porphyrin interactions tune the Au network size whose dimension can easily be read out, being the position of the surface plasmon resonance strongly indicative of this size. The present system can be used for all the applications requiring plasmonic and luminescent emitters.
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Mondal, Monosij, Maicol A. Ochoa, Maxim Sukharev i Abraham Nitzan. "Coupling, lifetimes, and “strong coupling” maps for single molecules at plasmonic interfaces". Journal of Chemical Physics 156, nr 15 (21.04.2022): 154303. http://dx.doi.org/10.1063/5.0077739.
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The interaction between excited states of a molecule and excited states of a metal nanostructure (e.g., plasmons) leads to hybrid states with modified optical properties. When plasmon resonance is swept through molecular transition frequency, an avoided crossing may be observed, which is often regarded as a signature of strong coupling between plasmons and molecules. Such strong coupling is expected to be realized when 2|⟨ U⟩|/ ℏΓ > 1, where ⟨ U⟩ and Γ are the molecule–plasmon coupling and the spectral width of the optical transition, respectively. Because both ⟨ U⟩ and Γ strongly increase with decreasing distance between a molecule and a plasmonic structure, it is not obvious that this condition can be satisfied for any molecule–metal surface distance. In this work, we investigate the behavior of ⟨ U⟩ and Γ for several geometries. Surprisingly, we find that if the only contributions to Γ are lifetime broadenings associated with the radiative and nonradiative relaxation of a single molecular vibronic transition, including effects on molecular radiative and nonradiative lifetimes induced by the metal, the criterion 2|⟨ U⟩|/ ℏΓ > 1 is easily satisfied by many configurations irrespective of the metal–molecule distance. This implies that the Rabi splitting can be observed in such structures if other sources of broadening are suppressed. Additionally, when the molecule–metal surface distance is varied keeping all other molecular and metal parameters constant, this behavior is mitigated due to the spectral shift associated with the same molecule–plasmon interaction, making the observation of Rabi splitting more challenging.
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Cao, En, Weihua Lin, Mengtao Sun, Wenjie Liang i Yuzhi Song. "Exciton-plasmon coupling interactions: from principle to applications". Nanophotonics 7, nr 1 (1.01.2018): 145–67. http://dx.doi.org/10.1515/nanoph-2017-0059.
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AbstractThe interaction of exciton-plasmon coupling and the conversion of exciton-plasmon-photon have been widely investigated experimentally and theoretically. In this review, we introduce the exciton-plasmon interaction from basic principle to applications. There are two kinds of exciton-plasmon coupling, which demonstrate different optical properties. The strong exciton-plasmon coupling results in two new mixed states of light and matter separated energetically by a Rabi splitting that exhibits a characteristic anticrossing behavior of the exciton-LSP energy tuning. Compared to strong coupling, such as surface-enhanced Raman scattering, surface plasmon (SP)-enhanced absorption, enhanced fluorescence, or fluorescence quenching, there is no perturbation between wave functions; the interaction here is called the weak coupling. SP resonance (SPR) arises from the collective oscillation induced by the electromagnetic field of light and can be used for investigating the interaction between light and matter beyond the diffraction limit. The study on the interaction between SPR and exaction has drawn wide attention since its discovery not only due to its contribution in deepening and broadening the understanding of SPR but also its contribution to its application in light-emitting diodes, solar cells, low threshold laser, biomedical detection, quantum information processing, and so on.
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Chaudhari, D. K., i B. R. Ghimire. "Study of Signal Transmission through different Array of Cu, Au and Ag Nanospheres". Journal of Nepal Physical Society 4, nr 1 (22.05.2017): 42. http://dx.doi.org/10.3126/jnphyssoc.v4i1.17335.
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<p>Twenty first century is the age of Information Technology and we always look for faster information transport and processing capabilities. Data can be moved by transistors and optical fibers. Transistors carry small amount of data and are small in size while optical fibers can carry huge amount of data but are much bigger in size. Metal nanostructures may possess right combination of electric and optical properties to tackle the issues outlined above and realized the dream of significantly faster processing speeds. In this work, dispersion relation in Plasmon modes in linear chain and alternated chain of nanoparticles like silver-gold, silver-copper and gold-copper were studied. Expressions of angular frequency of Plasmon modes, group-velocity and extinction-coefficient were derived by solving equation of motion of Plasmon oscillation on the single kind of nanoparticle and that on different alternated chain of nanoparticles. Expressions of angular frequency of Plasmon modes, group velocity and extinction coefficient were tested for specific linear chain of nanoparticles. Extinction coefficients for the linear chain of Copper, gold and silver nanoparticles were found to be less and group velocities higher than that of alternated silver-gold and alternated gold-copper at their respective resonance frequencies.</p><p><strong>Journal of Nepal Physical Society</strong><em><br /></em>Volume 4, Issue 1, February 2017, Page: 42-48</p>
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Kuzmin, Dmitry A., Igor V. Bychkov, Vladimir G. Shavrov i Vasily V. Temnov. "Plasmonics of magnetic and topological graphene-based nanostructures". Nanophotonics 7, nr 3 (23.02.2018): 597–611. http://dx.doi.org/10.1515/nanoph-2017-0095.
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AbstractGraphene is a unique material in the study of the fundamental limits of plasmonics. Apart from the ultimate single-layer thickness, its carrier concentration can be tuned by chemical doping or applying an electric field. In this manner, the electrodynamic properties of graphene can be varied from highly conductive to dielectric. Graphene supports strongly confined, propagating surface plasmon polaritons (SPPs) in a broad spectral range from terahertz to mid-infrared frequencies. It also possesses a strong magneto-optical response and thus provides complimentary architectures to conventional magneto-plasmonics based on magneto-optically active metals or dielectrics. Despite a large number of review articles devoted to plasmonic properties and applications of graphene, little is known about graphene magneto-plasmonics and topological effects in graphene-based nanostructures, which represent the main subject of this review. We discuss several strategies to enhance plasmonic effects in topologically distinct closed surface landscapes, i.e. graphene nanotubes, cylindrical nanocavities and toroidal nanostructures. A novel phenomenon of the strongly asymmetric SPP propagation on chiral meta-structures and the fundamental relations between structural and plasmonic topological indices are reviewed.
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Kumar, Jatish, Xingzhan Wei, Steven J. Barrow, Alison M. Funston, K. George Thomas i Paul Mulvaney. "Coupled Plasmon Resonances and Gap Modes in Laterally Assembled Gold Nanorod Arrays". Zeitschrift für Physikalische Chemie 232, nr 9-11 (28.08.2018): 1607–17. http://dx.doi.org/10.1515/zpch-2018-1163.
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Abstract The assembly of metal nanocrystals offers a flexible method for creating new materials with tunable, size-dependent optical properties. Here we study the lateral assembly of gold nanorods into arrays, which leads to strong colour changes due to surface plasmon coupling. We also demonstrate the first example of gap modes in colloid systems, an optical mode in which light waves propagate in the channels between the gold rods. Such modes resonate at wavelengths which strongly depend on the gap width and length.
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Romashkina, A. M., V. B. Novikov i T. V. Murzina. "Nonlinear TMOKE enhancement in 1D Au/Py magnetoplasmonic crystals". Journal of Physics: Conference Series 2015, nr 1 (1.11.2021): 012126. http://dx.doi.org/10.1088/1742-6596/2015/1/012126.
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Abstract Resonant optical properties of the magnetoplasmonic crystals, which support propagation of surface plasmon polaritons (SPPs) accompanied by magnetooptical effects, have found success in magnetic field driven control of optical radiation. In this work we investigate the resonant magnetooptical effects in the second harmonic generation in the magnetoplasmonic crystal formed by gold/pemalloy bifilm covering dielectric grating. Strong transverse magnetooptical Kerr with the contrast up to 30% is revealed in the spectral vicinity of the SPP excitation.
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Yan, Tingzhen, Ruijin Hong, Jiqing Lian, Chunxian Tao, Hui Lin, Qi Wang, Zhaoxia Han i Dawei Zhang. "Tunable Nonlinear Optical Response of ITO Films with Au@Ag Bimetallic Nanoparticles". Nanomaterials 13, nr 10 (13.05.2023): 1631. http://dx.doi.org/10.3390/nano13101631.
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The nonlinear optical (NLO) response of indium tin oxide films covered with Au@Ag colloid layer was characterized by a femtosecond single-beam open aperture (OA) Z-scan technique in this study. As the Au@Ag thickness increased, the transition from saturated absorption (SA) to reverse saturated absorption (RSA) was found in these ITO matrix composites. The nonlinear absorption coefficient for these composite materials can be regulated from −6.85 × 10−7 m/W to 26.06 × 10−7 m/W. In addition, this work also characterized the structure, morphology, and other optical properties of the specimen, and the finite-difference time-domain (FDTD) results were consistent with the experimental results. The NLO response of the ITO/Au@Ag composites can be attributed to the phase properties, synergistic competition effect, strong interaction based on the epsilon-near-zero (ENZ) mode, and localized surface plasmon resonance (LSPR) between the indium tin oxide films and Au@Ag.
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KODAIRA, TETSUYA, YASUO NOZUE, SATOSHI OHWASHI, NOZOMU TOGASHI i OSAMU TERASAKI. "MAGNETIC AND OPTICAL PROPERTIES OF SODIUM CLUSTERS IN ZEOLITE LTA". Surface Review and Letters 03, nr 01 (luty 1996): 717–20. http://dx.doi.org/10.1142/s0218625x96001297.
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Cationic Na clusters are formed in the α and β cages of Na-form LTA by incorporating Na atoms from vapor. The maximum number of Na atoms incorporated is 4.9 per unit cell. Ac magnetic susceptibilities and optical reflection spectra are measured as a function of Na loading density. Na clusters show diamagnetism independent of Na loading density while K clusters in K-LTA and Rb clusters in Rb-LTA show ferromagnetism at certain loading densities. All Na clusters contain therefore an even number of the electrons, which are supplied from 3s-electrons of the guest Na atoms, irrespective of the cages they are formed. The electron-phonon interaction plays an important role in stabilizing the singlet state. In the reflection spectra of highly loaded sample, a strong band is observed at 1.95 eV. An oscillator strength of this band exceeds unity per cluster by a great deal. This band is assigned to surface-plasmon-like excitation of Na cluster formed in α cage.
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Deng, Fu, Hongfeng Liu, Yuanyuan Peng, Mingcheng Panmai i Sheng Lan. "Optical Scattering of Liquid Gallium Nanoparticles Coupled to Thin Metal Films". Nanomaterials 10, nr 6 (30.05.2020): 1052. http://dx.doi.org/10.3390/nano10061052.
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We investigate experimentally and numerically the scattering properties of liquid gallium nanoparticles coupled to a thin gold or silver film. The gallium nanoparticles are excited either directly by using inclined white light or indirectly by surface plasmon polaritons generated on the surface of the gold/silver film. In the former case, the scattering spectrum is always dominated by a scattering peak at ∼540 nm with a long-wavelength shoulder which is redshifted with increasing diameter of the gallium nanoparticle. Under the excitation of the surface plasmon polaritons, optical resonances with much narrower linewidths, which are dependent on the incidence angle of the white light, appear in the scattering spectra. In this case, the scattering spectrum depends weakly on the diameter of the gallium nanoparticle but the radiation pattern exhibits a strong dependence. In addition, a significant enhancement of electric field is expected in the gap region between the gallium nanoparticles and the gold film based on numerical simulation. As compared with the gallium nanoparticle coupled to the gold film which exhibit mainly yellow and orange colors, vivid scattering light spanning the visible light spectrum can be achieved in the gallium nanoparticles coupled to the silver film by simply varying the incidence angle. Gallium nanoparticles coupled to thin metal films may find potential applications in light–matter interaction and color display.
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Taylor, Mitchell Lee, Raymond Edward Wilson, Kristopher Daniel Amrhein i Xiaohua Huang. "Gold Nanorod-Assisted Photothermal Therapy and Improvement Strategies". Bioengineering 9, nr 5 (5.05.2022): 200. http://dx.doi.org/10.3390/bioengineering9050200.
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Noble metal nanoparticles have been sought after in cancer nanomedicine during the past two decades, owing to the unique localized surface plasmon resonance that induces strong absorption and scattering properties of the nanoparticles. A popular application of noble metal nanoparticles is photothermal therapy, which destroys cancer cells by heat generated by laser irradiation of the nanoparticles. Gold nanorods have stood out as one of the major types of noble metal nanoparticles for photothermal therapy due to the facile tuning of their optical properties in the tissue penetrative near infrared region, strong photothermal conversion efficiency, and long blood circulation half-life after surface modification with stealthy polymers. In this review, we will summarize the optical properties of gold nanorods and their applications in photothermal therapy. We will also discuss the recent strategies to improve gold nanorod-assisted photothermal therapy through combination with chemotherapy and photodynamic therapy.
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Gupta, Banshi D., Anisha Pathak i Vivek Semwal. "Carbon-Based Nanomaterials for Plasmonic Sensors: A Review". Sensors 19, nr 16 (13.08.2019): 3536. http://dx.doi.org/10.3390/s19163536.
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The surface plasmon resonance (SPR) technique is a remarkable tool, with applications in almost every area of science and technology. Sensing is the foremost and majorly explored application of SPR technique. The last few decades have seen a surge in SPR sensor research related to sensitivity enhancement and innovative target materials for specificity. Nanotechnological advances have augmented the SPR sensor research tremendously by employing nanomaterials in the design of SPR-based sensors, owing to their manifold properties. Carbon-based nanomaterials, like graphene and its derivatives (graphene oxide (GO)), (reduced graphene oxide (rGO)), carbon nanotubes (CNTs), and their nanocomposites, have revolutionized the field of sensing due to their extraordinary properties, such as large surface area, easy synthesis, tunable optical properties, and strong compatible adsorption of biomolecules. In SPR based sensors carbon-based nanomaterials have been used to act as a plasmonic layer, as the sensitivity enhancement material, and to provide the large surface area and compatibility for immobilizing various biomolecules, such as enzymes, DNA, antibodies, and antigens, in the design of the sensing layer. In this review, we report the role of carbon-based nanomaterials in SPR-based sensors, their current developments, and challenges.
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Li, Guang-Can, Qiang Zhang, Stefan A. Maier i Dangyuan Lei. "Plasmonic particle-on-film nanocavities: a versatile platform for plasmon-enhanced spectroscopy and photochemistry". Nanophotonics 7, nr 12 (26.11.2018): 1865–89. http://dx.doi.org/10.1515/nanoph-2018-0162.
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AbstractMetallic nanostructures with nanometer gaps support hybrid plasmonic modes with an extremely small mode volume and strong local field intensity, which constitutes an attractive plasmonic platform for exploring novel light-matter interaction phenomena at the nanoscale. Particularly, the plasmonic nanocavity formed by a metal nanoparticle closely separated from a thin metal film has received intensive attention in the nanophotonics community, largely attributed to its ease of fabrication, tunable optical properties over a wide spectral range, and the ultrastrong confinement of light at the small gap region scaled down to sub-nanometer. In this article, we review the recent exciting progress in exploring the plasmonic properties of such metal particle-on-film nanocavities (MPoFNs), as well as their fascinating applications in the area of plasmon-enhanced imaging and spectroscopies. We focus our discussion on the experimental fabrication and optical characterization of MPoFNs and the theoretical interpretation of their hybridized plasmon modes, with particular interest on the nanocavity-enhanced photoluminescence and Raman spectroscopies, as well as photocatalysis and molecular nanochemistry.
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Cao, J. X., H. Liu, S. M. Wang, Y. J. Zheng, C. Zhu, Y. Wang i S. N. Zhu. "Magnetic Plasmon Sensing in Twisted Split-Ring Resonators". Advances in OptoElectronics 2012 (30.05.2012): 1–5. http://dx.doi.org/10.1155/2012/609691.
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We studied the sensing properties of stereo-SRRs metamaterials composed from two twisted split-ring resonators (SRRs). Due to the strong hybridization effect in the system, the polarization state of the transmitted wave is greatly changed at resonances. Since the stereo-SRRs structure is strongly coupled to the surrounding medium, the polarization change of the transmitted waves is quite sensitive to the refractive index change of the environment medium. The polarization ratio PRtran = Ty/Tx is used as sensing parameter and its figure of merit can reach 22.3 at the hybridized magnetic plasmon resonance. The results showed that the stereo-SRRs metamaterial can be applied to optical sensors an or other related field.
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Ji, Guangmin, Jingkun Tian, Fei Xing i Yu Feng. "Optical Biosensor Based on Graphene and Its Derivatives for Detecting Biomolecules". International Journal of Molecular Sciences 23, nr 18 (16.09.2022): 10838. http://dx.doi.org/10.3390/ijms231810838.
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Graphene and its derivatives show great potential for biosensing due to their extraordinary optical, electrical and physical properties. In particular, graphene and its derivatives have excellent optical properties such as broadband and tunable absorption, fluorescence bursts, and strong polarization-related effects. Optical biosensors based on graphene and its derivatives make nondestructive detection of biomolecules possible. The focus of this paper is to review the preparation of graphene and its derivatives, as well as recent advances in optical biosensors based on graphene and its derivatives. The working principle of face plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence resonance energy transfer (FRET) and colorimetric sensors are summarized, and the advantages and disadvantages of graphene and its derivatives applicable to various types of sensors are analyzed, and the methods of surface functionalization of graphene and its derivatives are introduced; these optical biosensors can be used for the detection of a range of biomolecules such as single cells, cellular secretions, proteins, nucleic acids, and antigen-antibodies; these new high-performance optical sensors are capable of detecting changes in surface structure and biomolecular interactions with the advantages of ultra-fast detection, high sensitivity, label-free, specific recognition, and the ability to respond in real-time. Problems in the current stage of application are discussed, as well as future prospects for graphene and its biosensors. Achieving the applicability, reusability and low cost of novel optical biosensors for a variety of complex environments and achieving scale-up production, which still faces serious challenges.
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Zhou, Xiaodong, Erlei Wang, Sihua Zhou, Honglei Yuan, Yongmei Wang i Qiang Wang. "Controlling size and distribution of Ag nanoparticles in near surface of SiO2 glass by low-energy ion implantation". Materials Express 11, nr 12 (1.12.2021): 2010–14. http://dx.doi.org/10.1166/mex.2021.2115.
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Ag nanoparticles were embedded in the near surface of SiO2 substrate and fabricated by low-energy ion implantation method in this study. The optical and structural properties of Ag implanted samples were investigated using optical spectroscopy, transmission electron microscope (TEM) and atomic force microscopy (AFM). The grain size and distribution of nanoparticles embedded in the substrate were characterized by TEM and AFM characterization. Results showed that the grain size and depth of distribution of nanoparticles were controlled by changing the ion implantation energy and dose. Furthermore, the Ag nanoparticles embedded near surface of substrate prepared by this low-energy ion implantation method had strong local surface plasmon resonance (LSPR) characteristics. Our work demonstrates a practical means for fabrication of metal nanoparticles with controllable size and distribution using ion implantation technology, which is helpful to the application of local plasmon resonance effect of metal nanoparticles.
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Ung, Thi Phuong Lien, Rabeb Jazi, Julien Laverdant, Remy Fulcrand, Gérard Colas des Francs, Jean-Pierre Hermier, Xavier Quélin i Stéphanie Buil. "Scanning the plasmonic properties of a nanohole array with a single nanocrystal near-field probe". Nanophotonics 9, nr 4 (28.02.2020): 793–801. http://dx.doi.org/10.1515/nanoph-2019-0409.
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AbstractThe electromagnetic properties of ordered hole nanostructures in very thin metal films are characterized using CdSe/CdS nanocrystals (NCs) as nanoprobes. The characterization of the local density of optical states (LDOS) on the nanostructure is possible by the measurement of their photoluminescence decay rate. Statistical measurements are performed in the far field to show the average increase of optical modes. A determinist approach using an active single NC nanoprobe in the near field gives access to a more precise characterization of the LDOS. The optical properties of the structure come from the coupling between localized surface plasmons created by the holes and surface plasmon polaritons. A strong concentration of optical modes is observed around the holes thanks to the active near-field nanoprobe. With different NC orientations, the strong influence of the component perpendicular to the surface in the very near field of the LDOS is observed. Finite differential time domain simulations of the different components of the electric field in the very near field of the structure confirm that the localization of the electric field around the holes is only due to the normal component as observed with the nanoprobe.
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Zhang, Pei Chao, i Ying Hui Zhou. "Influence of Support Structure on the Ultraviolet Photoluminescence Enhancement from Graphene/ZnO Hybrid Structures". Key Engineering Materials 748 (sierpień 2017): 132–36. http://dx.doi.org/10.4028/www.scientific.net/kem.748.132.
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Novel application of graphene combined with light emitting materials has been proposed recently due to the plasmonic effects of graphene. Here, we report our investigations on the structural and optical properties of two graphene/ZnO hybrid structures that fabricated based on different ZnO supports. Plasmon-enhanced ultraviolet photoluminescence has been observed from both samples. The combined Raman and photoluminescence studies suggest a strong interaction between ZnO and graphene, which is affected by the surface structures of ZnO. Our results develop insights about the influence of ZnO supports on the PL enhancement and interfacial coupling in graphene/ZnO hybrid structures, which provides a reference for the design and fabrication of optoelectronic devices with high efficiency.
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Bai, Chunyan, Jiqing Lian, Xiangcai Ma, Peizhen Qiu, Dileep Kumar i Saima Kanwal. "Particle Trapping Properties of Metal Annular Slits under Vector Field Excitation". Photonics 10, nr 4 (13.04.2023): 445. http://dx.doi.org/10.3390/photonics10040445.
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This article presents the particle capture performance of annular slits, which offer a simple alternative to complex micro/nano structures used to excite and focus surface plasmon polaritons (SPPs). Additionally, the annular slits are compatible with a variety of vector light fields, generating diverse SPP field distributions under their excitation. These SPP fields can be regulated by varying the vector light field parameters, thereby offering the annular slit structure the ability to flexibly capture and manipulate particles. The rotation and movement of captured objects can be achieved by changing the position and phase difference of the incident beams with linear polarization. Different material and sized metallic particles can be stably captured with a radially polarized beam excitation due to the strong convergence. These capabilities are demonstrated by evaluating the optical force and trapping potential based on the finite difference time domain (FDTD) simulation. This study provides valuable insights into the practical application of annular slits for particle capture and manipulation.
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Chazapis, Nikolaos, Michalis Stavrou, Georgia Papaparaskeva, Alexander Bunge, Rodica Turcu, Theodora Krasia-Christoforou i Stelios Couris. "Iridium-Based Nanohybrids: Synthesis, Characterization, Optical Limiting, and Nonlinear Optical Properties". Nanomaterials 13, nr 14 (22.07.2023): 2131. http://dx.doi.org/10.3390/nano13142131.
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The present work reports on the synthesis and characterization of iridium (Ir)-based nanohybrids with variable chemical compositions. More specifically, highly stable polyvinylpyrrolidone (PVP) nanohybrids of the PVP-IrO2 and PVP-Ir/IrO2 types, as well as non-coated Ir/IrO2 nanoparticles, are synthesized using different synthetic protocols and characterized in terms of their chemical composition and morphology via X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), respectively. Furthermore, their nonlinear optical (NLO) response and optical limiting (OL) efficiency are studied by means of the Z-scan technique, employing 4 ns laser pulses at 532 and 1064 nm. The results demonstrate that the PVP-Ir/IrO2 and Ir/IrO2 systems exhibit exceptional OL performance, while PVP-IrO2 presents very strong saturable absorption (SA) behavior, indicating that the present Ir-based nanohybrids could be strong competitors to other nanostructured materials for photonic and optoelectronic applications. In addition, the findings denote that the variation in the content of IrO2 nanoparticles by using different synthetic pathways significantly affects the NLO response of the studied Ir-based nanohybrids, suggesting that the choice of the appropriate synthetic method could lead to tailor-made NLO properties for specific applications in photonics and optoelectronics.
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Li, Shuang, Ziyue Qin, Jie Fu i Qiya Gao. "Nanobiosensing Based on Electro-Optically Modulated Technology". Nanomaterials 13, nr 17 (23.08.2023): 2400. http://dx.doi.org/10.3390/nano13172400.
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At the nanoscale, metals exhibit special electrochemical and optical properties, which play an important role in nanobiosensing. In particular, surface plasmon resonance (SPR) based on precious metal nanoparticles, as a kind of tag-free biosensor technology, has brought high sensitivity, high reliability, and convenient operation to sensor detection. By applying an electrochemical excitation signal to the nanoplasma device, modulating its surface electron density, and realizing electrochemical coupling SPR, it can effectively complete the joint transmission of electrical and optical signals, increase the resonance shift of the spectrum, and further improve the sensitivity of the designed biosensor. In addition, smartphones are playing an increasingly important role in portable mobile sensor detection systems. These systems typically connect sensing devices to smartphones to perceive different types of information, from optical signals to electrochemical signals, providing ideas for the portability and low-cost design of these sensing systems. Among them, electrochemiluminescence (ECL), as a special electrochemically coupled optical technology, has good application prospects in mobile sensing detection due to its strong anti-interference ability, which is not affected by background light. In this review, the SPR is introduced using nanoparticles, and its response process is analyzed theoretically. Then, the mechanism and sensing application of electrochemistry coupled with SPR and ECL are emphatically introduced. Finally, it extends to the relevant research on electrochemically coupled optical sensing on mobile detection platforms.
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Ma, Qiang, Chengda Pan, Yingxian Xue, Zhiyun Fang, Shiyu Zhang, Botao Wu i E. Wu. "Plasmon Enhanced Second Harmonic Generation from ZnO Nanofilms on Vertical Au Nanorod Arrays". Nanomaterials 11, nr 10 (2.10.2021): 2597. http://dx.doi.org/10.3390/nano11102597.
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Vertically aligned gold nanorod arrays have attracted much attention for their fascinating optical properties. Different from longitudinal surface plasmon wavelength (LSPW) and edge-to-edge spacing of gold nanorods, the role of gold nanorod diameter in plasmonic enhancement ability of vertical gold nanorod arrays has rarely been explored. In this work, we selected gold nanorods with similar LSPW but two different diameters (22 and 41 nm), the optical properties of which are dominated by absorption and scattering cross sections, respectively. The vertically aligned arrays of these gold nanorods formed by evaporation self-assembly are coupled with nonlinear ZnO nanocrystal films spin-coated on their surfaces. It was found that the gold nanorod array with a larger diameter can enhance the second harmonic generation (SHG) of ZnO nanofilm by a factor of 27.0, while it is about 7.3 for the smaller gold nanorod array. Theoretical simulations indicate that such stronger enhancement of the larger vertical gold nanorod array compared with the smaller one is due to its stronger scattering ability and greater extent of near-field enhancement at SHG fundamental wavelength. Our work shows that the diameter of gold nanorods is also an important factor to be considered in realizing strong plasmon enhancement of vertically aligned gold nanorod arrays.
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Li, Quanjiang, Jingang Wang, Shenghui Chen i Meishan Wang. "Impurity Controlled near Infrared Surface Plasmonic in AlN". Nanomaterials 12, nr 3 (28.01.2022): 459. http://dx.doi.org/10.3390/nano12030459.
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In this work, we used multi-scale computational simulation methods combined with density functional theory (DFT) and finite element analysis (FEA) in order to study the optical properties of substitutional doped aluminium nitride (AlN). There was strong surface plasmon resonance (SPR) in the near-infrared region of AlN substituted with different alkali metal doping configurations. The strongest electric field strength reached 109 V/m. There were local exciton and charge transfer exciton behaviours in some special doping configurations. These research results not only improve the application of multi-scale computational simulations in quantum surface plasmons, but also promote the application of AlN in the field of surface-enhanced linear and non-linear optical spectroscopy.
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Sugiono, Friska Ayu Fitrianti, i Doty Dewi Risanti. "TUNABLE SURFACE PLASMON RESONANCES OF Au@TiO2 CORE-SHELL NANOPARTICLES ON THE DSSC (DYE SENSITIZED SOLAR CELLS) PERFORMANCE". Jurnal Sains Materi Indonesia 20, nr 3 (30.04.2019): 106. http://dx.doi.org/10.17146/jsmi.2019.20.3.5452.
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Plasmonic core-shell nanoparticles, i.e. gold can improve the efficiency of Dye-sensitized Solar Cell by increase the light harvesting due to the strong near-field effect LSPR (Localized Surface Plasmon Resonance). To achieve maximum enhancement, the morphology of core-shell need to be optimized with coated either by insulator such as semiconductor, i.e. TiO2. In this paper, morphology of Au@TiO2 core-shell precisely control by various TiO2 volume and systematically study its influence on the plasmonic enhancement effect. A gold solution was prepared using Turkevich method. The crystal structure of the powders was determined by powder X-ray diffraction (XRD). The optical properties were measured by UV-Vis absorption spectroscopy using UV-Vis Lambda 750. The photocurrent action spectra or IPCE in visible light spectrum was obtained by adjusting wavelength of incident light, i.e. series connection of halogen lamp and monochromator. UV-Vis absorption spectra of core–shell showed the position of the surface plasmon Au band in the range of 500–550 nm. According to UV-Vis characterization, all samples studied show weak surface plasmon resonance response (~520 to 550 nm) as indicative of the thick TiO2 shells for individual core-shell Au@TiO2.Tunable Surface Plasmon Resonances of Au@TiO2 Core-shell Nanoparticles on the DSSC (Dye Sensitized Solar Cells) Performance
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Li, Jinze, Xin Liu, Jiawei Xi, Li Deng, Yanxin Yang, Xiang Li i Hao Sun. "Recent Development of Polymer Nanofibers in the Field of Optical Sensing". Polymers 15, nr 17 (31.08.2023): 3616. http://dx.doi.org/10.3390/polym15173616.
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In recent years, owing to the continuous development of polymer nanofiber manufacturing technology, various nanofibers with different structural characteristics have emerged, allowing their application in the field of sensing to continually expand. Integrating polymer nanofibers with optical sensors takes advantage of the high sensitivity, fast response, and strong immunity to electromagnetic interference of optical sensors, enabling widespread use in biomedical science, environmental monitoring, food safety, and other fields. This paper summarizes the research progress of polymer nanofibers in optical sensors, classifies and analyzes polymer nanofiber optical sensors according to different functions (fluorescence, Raman, polarization, surface plasmon resonance, and photoelectrochemistry), and introduces the principles, structures, and properties of each type of sensor and application examples in different fields. This paper also looks forward to the future development directions and challenges of polymer nanofiber optical sensors, and provides a reference for in-depth research of sensors and industrial applications of polymer nanofibers.
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Grochowska, Katarzyna, Katarzyna Siuzdak, Peter A. Atanasov, Carla Bittencourt, Anna Dikovska, Nikolay N. Nedyalkov i Gerard Śliwiński. "Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films". Beilstein Journal of Nanotechnology 5 (13.11.2014): 2102–12. http://dx.doi.org/10.3762/bjnano.5.219.
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A brief description of research advances in the area of short-pulse-laser nanostructuring of thin Au films is followed by examples of experimental data and a discussion of our results on the characterization of structural and optical properties of gold nanostructures. These consist of partially spherical or spheroidal nanoparticles (NPs) which have a size distribution (80 ± 42 nm) and self-organization characterized by a short-distance order (length scale ≈140 nm). For the NP shapes produced, an observably broader tuning range (of about 150 nm) of the surface plasmon resonance (SPR) band is obtained by renewal thin film deposition and laser annealing of the NP array. Despite the broadened SPR bands, which indicate damping confirmed by short dephasing times not exceeding 4 fs, the self-organized Au NP structures reveal quite a strong enhancement of the optical signal. This was consistent with the near-field modeling and micro-Raman measurements as well as a test of the electrochemical sensing capability.
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Ferrera, Marzia, Lorenzo Ramò, Domenica Convertino, Giorgio Orlandini, Simona Pace, Ilya Milekhin, Michele Magnozzi i in. "Optical Response of CVD-Grown ML-WS2 Flakes on an Ultra-Dense Au NP Plasmonic Array". Chemosensors 10, nr 3 (21.03.2022): 120. http://dx.doi.org/10.3390/chemosensors10030120.
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The combination of metallic nanostructures with two-dimensional transition metal dichalcogenides is an efficient way to make the optical properties of the latter more appealing for opto-electronic applications. In this work, we investigate the optical properties of monolayer WS2 flakes grown by chemical vapour deposition and transferred onto a densely-packed array of plasmonic Au nanoparticles (NPs). The optical response was measured as a function of the thickness of a dielectric spacer intercalated between the two materials and of the system temperature, in the 75–350 K range. We show that a weak interaction is established between WS2 and Au NPs, leading to temperature- and spacer-thickness-dependent coupling between the localized surface plasmon resonance of Au NPs and the WS2 exciton. We suggest that the closely-packed morphology of the plasmonic array promotes a high confinement of the electromagnetic field in regions inaccessible by the WS2 deposited on top. This allows the achievement of direct contact between WS2 and Au while preserving a strong connotation of the properties of the two materials also in the hybrid system.
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Yu, Yan, Yujun Xie, Pan Zeng, Dai Zhang, Rongqing Liang, Wenxing Wang, Qiongrong Ou i Shuyu Zhang. "Morphology-Tailored Gold Nanoraspberries Based on Seed-Mediated Space-Confined Self-Assembly". Nanomaterials 9, nr 9 (27.08.2019): 1202. http://dx.doi.org/10.3390/nano9091202.
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Raspberry-like structure, providing a high degree of symmetry and strong interparticle coupling, has received extensive attention from the community of functional material synthesis. Such structure constructed in the nanoscale using gold nanoparticles has broad applicability due to its tunable collective plasmon resonances, while the synthetic process with precise control of the morphology is critical in realizing its target functions. Here, we demonstrate a synthetic strategy of seed-mediated space-confined self-assembly using the virus-like silica (V-SiO2) nanoparticles as the templates, which can yield gold nanoraspberries (AuNRbs) with uniform size and controllable morphology. The spikes on V-SiO2 templates serve dual functions of providing more growth sites for gold nanoseeds and activating the space-confined effect for gold nanoparticles. AuNRbs with wide-range tunability of plasmon resonances from the visible to near infrared (NIR) region have been successfully synthesized, and how their geometric configurations affect their optical properties is thoroughly discussed. The close-packed AuNRbs have also demonstrated huge potential in Raman sensing due to their abundant “built-in” hotspots. This strategy offers a new route towards synthesizing high-quality AuNRbs with the capability of engineering the morphology to achieve target functions, which is highly desirable for a large number of applications.
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Akinsiku, Anuoluwa Abimbola, Enock Olugbenga Dare, Kolawole Oluseyi Ajanaku, Olayinka Oyewale Ajani, Joseph Adebisi O. Olugbuyiro, Tolutope Oluwasegun Siyanbola, Oluwaseun Ejilude i Moses Eterigho Emetere. "Modeling and Synthesis of Ag and Ag/Ni Allied Bimetallic Nanoparticles by Green Method: Optical and Biological Properties". International Journal of Biomaterials 2018 (2018): 1–17. http://dx.doi.org/10.1155/2018/9658080.
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In the quest for environmental remediation which involves eco-friendly synthetic routes, we herein report synthesis and modeling of silver nanoparticles (Ag NPs) and silver/nickel allied bimetallic nanoparticles (Ag/Ni NPs) using plant-extract reduction method. Secondary metabolites in the leaf extract of Canna indica acted as reducing agent. Electronic transitions resulted in emergence of surface plasmon resonance in the regions of 416 nm (Ag NPs) and 421 nm (Ag/Ni NPs) during optical measurements. Further characterizations were done using TEM and EDX. Antimicrobial activity of the nanoparticles against clinical isolates was highly significant as P<0.05. These findings suggest application of Ag NPs as antibacterial agent against E. coli, S. pyogenes, and antifungal agent against C. albicans. Possible antibacterial drugs against S. pyogenes and E. coli can also be designed using Ag/Ni nanohybrid based on their strong inhibition activities. Similarly, the enhanced SPR in the nanoparticles is suggested for applications in optical materials, as good absorbers and scatters of visible light. Theoretical model clarified that the experiment observation on the relationship between metallic nanoparticles penetration through peptidoglycan layers and the activeness of microbial species depends on the nature of the nanoparticles and pore size of the layer.
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Yousif, Bedir B., i Ahmed S. Samra. "Modeling of Optical Nanoantennas". Physics Research International 2012 (8.11.2012): 1–10. http://dx.doi.org/10.1155/2012/321075.
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The optical properties of plasmonic nanoantennas are investigated in detail using the finite integration technique (FIT). The validity of this technique is verified by comparison to the exact solution generalized Mie method (GMM). The influence of the geometrical parameters (antenna length, gap dimension, and shapes) on the antenna field enhancement and spectral response is discussed. Localized surface plasmon resonances of Au (gold) dimers nanospheres, bowtie, and aperture bowtie nanoantennas are modeled. The enhanced field is equivalent to a strong light spot which can lead to the resolution improvement of the microscopy and optical lithography, thus increasing the optical data storage capacity. Furthermore, the sensitivity of the antennas to index changes of the environment and substrate is investigated in detail for biosensing applications. We confirm that our approach yields an exact correspondence with GMM theory for Au dimers nanospheres at gap dimensions 5 nm and 10 nm but gives an approximation error of less than 1.37% for gap dimensions 1 nm and 2 nm with diameters approaching 80 nm. In addition, the far-field characteristics of the aperture bowtie nanoantenna such as directivity and gain are studied. The promising results of this study may have useful potential applications in near-field sample detection, optical microscopy, and so forth.