Perspective low-macroscopic field (LMF) emission prototype cathodes based on fullerene C60—doped porous silicon were realized via a two-stage technique comprising the electrochemical etching process of a monocrystalline silicon wafer and functionalization of the acquired porous silicon (PS) matrix with silver-doped fullerene-based carbon structures. The resulting LMF cathode prototypes were studied with SEM and EDS techniques. The formation of an amorphous silver-doped C60-based layer consisting of nanosized aggregates on the matrix surface was established. The emission characteristics of the prototypes were analyzed, crucial parameters including threshold field strength values, emission current density, and effective potential barrier height for electrons were considered. A novel LMF emission model is suggested. It was established that the emitter prototypes realized during this study are on par with or superior to modern and promising field cathodes.
Introduction. Porous silicon (PS) and materials on its basis are of interest for application in nanoelectronics, targeted drug delivery and advanced gas sensors. In addition, PS-based nanostructures are promising as filters in fibre-optic communication systems, since conventional thin-film deposition filters possess sidebands in their operating range thus requiring high vacuum for nanometer-thick coatings.Aim. To develop optical band-stop filter prototypes based on composite magnetic nanoparticles and the effect of localized surface plasmon resonance (LSPR) in an array of silver nanoparticles located on the PS surface. Materials and methods. The development and synthesis of nanostructures for the creation of filter prototypes. The double differentiation method in conjunction with Mie absorption theory was used for processing and analyzing the prototypes attenuation characteristics.Results. Two prototypes were developed. An analysis of the attenuation characteristics of a prototype based on SiO2 matrix functionalized by FemOn indicated that the parameters of the detected absorption bands depend on the size of FemOn nanoparticles. The attenuation characteristics of the LSPR-based prototype contain two absorption bands. The center wavelength value in the band caused by LSPR in the array of silver nanoparticles, close to spherical, is 367.5 nm. Excitation of LSPR in silver quantum clusters, manifested by the appearance of the corresponding band, occurs at a wavelength of 265.5 nm. The suppression in each of the bands can be controlled by changing the parameters of the PS matrix synthesis.Conclusion. Despite the disadvantages, e.g. a relatively low accuracy in setting the center wavelength, as well as certain difficulties concerned with reducing the unevenness in the absorption band, the obtained prototypes surpass existing analogues and are prospective for the development of compact analysis and diagnostics systems in a wide energy range.
Разработана технология синтеза плазмонного фильтра на основе массива наночастиц. Реализо-ван прототип фильтра на основе плазмонного резонанса в массиве наночастиц серебра с двумя по-лосами поглощения 260 и 360 нм. Методом электронно-абсорбционной спектроскопии исследованы характеристики затухания фильтров в зависимости от параметров синтеза. Показана возможность достижения уровня оптического подавления фильтра до 40 дБ путем синтеза массива плазмонных наночастиц, обладающих меньшим разбросом по размерам и фрактальностью. Выявлено превосход-ство данного типа фильтра над интерференционным по диапазону регулировки положения полосы затухания.ПОЛОСНО-ЗАГРАЖДАЮЩИЙ ФИЛЬТР; ПЛАЗМОННЫЙ РЕЗОНАНС; ФЛУОРЕСЦЕНТ-НАЯ МИКРОСКОПИЯ; МОДЕЛЬ ДРУДЕ; ФРАКТАЛЫ; МЕТОД УННО-ИМАИ..A synthesis technique for plasmonic array of silver nanoparticles has been developed. Double absorption band (260 nm and 360 nm) UV-Vis filter based on plasmon resonance of functionalized silver nanoparticles array has been created. The dependence of the prototype's attenuation characteristics on synthesis parameters is investigated utilizing the Electronic Absorption Spectroscopy technique. We have proved it was possible to achieve a sufficient level of optical attenuation (up to 40 d�) by producing an array of plasmonic nanoparticles with less variations in size and less fractality while increasing the anodizing current density of the silicon matrix. The superiority of the plasmon filter over the interference filter in terms of adjusting the attenuation band position has been revealed. �AND-STOP FILTER; PLASMON RESONANCE; FLUORESCENCE MICROSCOPY; DRUDE MODEL; FRACTALS; UNNO-IMAI TECHNIQUE.
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