Influence of Silver Nanoparticles Crystallinity on Localized Surface Plasmons Dephasing Times

Abstract

The dephasing time of localized surface plasmons is a crucial parameter that defines the quality of resonance and achievable electromagnetic field enhancement near metal nanoparticles. Lattice irregularities of as‐deposited supported metal nanoparticles shorten the plasmon dephasing time and degrade the resonance quality. To study the crystallinity influence on the plasmon dephasing time in more detail, silver nanoparticles in the form of a granular film were produced on dielectric substrates via physical vapor deposition in a vacuum chamber. The samples are characterized using Vis–NIR spectroscopy and transmission electron microscopy. The persistent spectral hole burning technique is applied to study the annealing influence on the dephasing time of localized surface plasmons of the particular resonance frequency. After annealing, the improved crystallinity of nanoparticles leads to a twofold dephasing time increase. This conclusion is supported by the electron diffraction patterns. The role of the improved crystallinity among concurrent effects of annealing is discussed.

Polarized Stimulated Emission of 2D Ensembles of Plasmonic Nanolasers

“…More details on the experimental setup, growing of NPs, and micrographs were given previously in the study by Toropov and co‐workers. [ 44,45 ] and in the Supporting Information. Using these micrographs and measuring the concentration of dye molecules dissolved from the surface, we estimated the surface density of plasmonic NPs which has an order of 10 10 cm −2 , their lateral sizes in average were of 60 nm in diameters with a big distribution, the thickness of dye layers, about 700 nm, and the ratio of 2000 molecules per a NP.…”

Silver Nanoparticle Arrays onto Glass Substrates Obtained by Solid-State Thermal Dewetting: A Morphological, Structural and Surface Chemical Study

“…Nonetheless, thermal annealing is probably the simplest way to promote dewetting, particularly when working on large areas. Deposited metallic films with thickness of a few nanometers are defective metastable layers that are comprised of polycrystalline grains (formed in a Volmer-Wever growth mode) with nanoscale islands that strain toward each other as they merge [25,28,41,46,47,57,58]. Then, dewetting can occur at temperatures considerably below the melting point of the material, highlighting the island structure, which appears in the initial pristine polycrystalline precursor film [25,28,41,46,47,57].…”

Сравнительные Измерения Фотоэлектронной Эмиссии В Массивных Образцах И Островковых Пленках Серебра

“…Для объяснения этого явления можно предположить следующее: в процессе осаждения атомы не успевают занять наиболее энергетически выгодные состояния (образовать кристалл). В [18] с помощью электронограммы показано, что гранулы напыленной, но не отожженной пленки имеют большое количество дефектов, так что структура этих гранул близка к аморфной. Такие дефекты на поверхности островка могут привести к образованию значительного количества локализованных заполненных состояний, лежащих выше уровня Ферми.…”