An analytical expression is obtained for the shape of a coherent kinoform X-ray lens surface, which is different from a parabola. A lens with a focal length of 1 m for monochromatic radiation with a photon energy of 12 keV is calculated. Two refractive lens materials—Rose’s alloy and silver—are selected. With a lens diameter of 200 μm, the diameter of the central diffraction maximum at the focus, calculated using the Huygens–Fresnel principle, is about 1 μm. The fraction of the light flux power incident on the lens in the central diffraction maximum of the focal spot is 14.6

AbstractThe results of applying two-photon femtosecond laser photopolymerization for fabrication of structures for sensitive IR sensors are reported. Two methods of sensor fabrication, a two-wave laser stereolithography and an electron-beam lithography, are compared. The possibility of applying the obtained structures for investigation of the effect of surface-enhanced IR absorption (SEIRA) with a STED-compatible oligomer pentaerythritol tetraacrylate (PETTA) as an analytical layer is demonstrated.

Обсуждены люминесцентные свойства гибридных наноструктур, построенных из коллоидных квантовых точек (КТ) CdS, пасивированных тиогликолевой кислотой, трис-(теноилтрифторацетоната) европия (III) и молекул красителя метиленового голубого.Обнаружены спектральные признаки формирования КТ типа ядро/оболочка CdS/CdS : Eu 3+ .Отмечена вероятность адсорбции комплекса европия на интерфейсах КТ и формирования КТ CdS/TGA/Eu 3+ .Получены спектральные закономерности, демонстрирующие безызлучательный перенос энергии от центров рекомбинационной люминесценции КТ CdS к ионам Eu 3+ в структурах CdS/CdS : Eu 3+ и CdS/TGA/Eu 3+ , проявляющиеся в тушении рекомбинационной люминесценции КТ и разгорании внутрицентровой люминесценции Eu 3+ , усиливающимся с ростом концентрации комплекса европия.При ассоциации таких структур с молекулами метиленового голубого обнаружено увеличение полуширины спектров его поглощения на 10-15% при неизменном положении максимума полосы поглощения.С увеличением концентрации молекул метиленового голубого наблюдали падение интенсивности как рекомбинационной полосы люминесценции КТ CdS с длиной волны 530 nm, так и люминесценции ионов Eu 3+ и одновременное разгорание флуоресценции метиленового голубого

The luminescent properties of hybrid nanostructures constructed from colloidal quantum dots (QDs) of CdS passivated with thioglycolic acid, europium(III) tris(tenoyltrifluoroacetonate), and methylene blue dye molecules are studied. Spectral features typical for the formation of core/shell QDs of the CdS/CdS:Eu 3+ type are found. It is noted that the adsorption of the europium complex at the QD interfaces and the formation of QDs of the CdS/TGA/Eu 3+ are probable. Spectral patterns that reveal nonradiative energy transfer from the recombination luminescence centers of CdS QDs to the Eu 3+ ions in the CdS/CdS:Eu 3+ and CdS/TGA/Eu 3+ structures are obtained. This is manifested in quenching the recombination luminescence of QDs and in the ignition of the intracentric luminescence of Eu 3+ , which enhance with an increase in the concentration of the europium complex. When such structures are combined with methylene blue molecules, the half-width of the absorption spectra is found to increase by 10–15% with an unchanged position of the absorption band maximum. With an increase in the concentration of methylene blue molecules, decreases in the intensity of the recombination luminescence band of CdS QDs at a wavelength of 530 nm and in the luminescence intensity of Eu 3+ ions and simultaneously the rise up of the fluorescence of methylene blue at a wavelength of about 675 nm are observed. At the same time, a decrease in the luminescence lifetime of the bands of QDs and europium ions are observed. It is concluded that the nonradiative excitation energy transfer from both the recombination luminescence centers and Eu 3+ ions to methylene blue molecules takes place.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A model describing a plasmonic nanopatch antenna based on triangular silver nanoprisms and multilayer cadmium chalcogenide quantum dots is introduced. Electromagnetic-field distributions in nanopatch antennas with different orientations of the quantum-dot dipoles are calculated for the first time with the finite element method for numerical electrodynamics simulations. The energy flux through the surface of an emitting quantum dot is calculated for the configurations with the dot in free space, on an aluminum substrate, and in a nanopatch antenna. It is shown that the radiative part of the Purcell factor is as large as 1.7 × 10 2 The calculated photoluminescence lifetimes of a CdSe/CdS/ZnS colloidal quantum dot in a nanopatch antenna based on a silver nanoprism agree well with the experimental results.

Исследована эффективность передачи энергии электронного возбуждения от органического полупроводникового материала TPD к полупроводниковым нанокристаллам CdSe/CdS/ZnS, пассивированным различными органическими лигандами. Показано, что с увеличением толщины слоя пассиватора скорость передачи возбуждения от TPD к нанокристаллам уменьшается. Высказано предположение о ферстеровском механизме передачи возбуждения. DOI: 10.21883/FTP.2017.05.44424.8475

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

We report on the results of studying quasi-two-dimensional nanostructures synthesized here in the form of semiconducting CdSe nanoplatelets with a characteristic longitudinal size of 20–70 nm and a thick-ness of a few atomic layers. Their morphology is studied using TEM and AFM and X-ray diffraction analysis; the crystal structure and sizes are determined. At room and cryogenic temperatures, the spectra and kinetics of the photoluminescence of such structures (quantum wells) are investigated. A hybrid light-emitting diode operating on the basis of CdSe nanoplatelets as a plane active element (emitter) is developed using the organic materials TAZ and TPD to form electron and hole transport layers, respectively. The spectral and current-voltage characteristics of the constructed device with a radiation wavelength λ = 515 nm are obtained. The device triggering voltage is 5.5 V (visible glow). The use of quasi-two-dimensional structures of this type is promising for hybrid light-emitting diodes with pure color and low operating voltages.

The reaction between aqueous zinc acetate and two moles of cymantrene carboxylic acid under mild conditions is found to give rise to {(H2O)Zn(μ,η2-OOCMe)[η5-C5H4(COO)]Mn(CO)3 polymer, whose reaction with 3,5-dimethylpyrazole yields binuclear pyrazolate-bridged complex Zn2(μ-dmpz)2(Hdmpz)2[η5-C5H4(COO)]Mn(CO)3]2. The structure of the resulting complexes was identified by X-ray diffraction.

The reactions of LaCl 3 and YCl 3 with 1,3-bis(1,3-dimethyl-1 H -pyrazol-4-yl)propane-1,3-dione (HL) and 1,10-phenanthroline (Phen) in the presence of a base afford complexes [La(L) 3 (Phen)] ( I ) and [Y(L) 3 (Phen)] ( II ). Unstable solvates I · iso -PrOH ( III ) and II · iso -PrOH ( IV ) are obtained from solutions of the complexes in 2-propanol, and their structures are determined by X-ray diffraction analysis (CIF files CCDC 1026802 ( III ) and 1026808 ( IV )). The compositions of the complexes are additionally studied by 1 H, 13 C, 89 Y, and 139 La NMR methods. Fragmentation is studied by laser desorption/ionization (LDI) and electrospray ionization (ESI) mass spectrometry.

Nanostructures in the form of 1.2-nm-thick colloidal CdSe nanoplatelets rolled into scrolls are investigated. The morphology of these scrolls is analysed and their basic geometric parameters are determined (diameter 29 nm, longitudinal size 100-150 nm) by TEM microscopy. Absorption and photoluminescence spectra of these objects are recorded, and the luminescence decay kinetics is studied. It is shown that the optical properties of CdSe nanoscrolls differ significantly from the properties of CdSe quantum dots and that these nanoscrolls are attractive for nanophotonic devices due to large oscillator strengths of the transition, small widths of excitonic peaks and short luminescence decay times. Nanoscrolls can be used to design hybrid organic-inorganic pure-color LEDs with a high luminescence quantum yield and low operating voltages.

Взаимодействием LaCl3 и YCl3 c 1,3-бис(1,3-диметил-1H-пиразол-4-ил)пропан-1,3-дионом (HL) и 1,10-фенатролином (Phen) в присутствии основания получены комплексы [La(L)3(Phen)] (I) и [Y(L)3(Phen)] (II). Из раствора комплексов в 2-пропаноле получены неустойчивые сольваты I · изо-PrOH (III), II · изо-PrOH (IV), структуры которых определены методом РСА (СIF files CCDC № 1 026 802 (III), 1 026 808 (IV)). Состав комплексов был дополнительно исследован методами ЯМР 1H, 13C, 89Y, 139La. Методом масс-спектрометрии изучена фрагментация в условиях ионизации лазерным излучением и электрораспылением.

An experimental observation of a new type of traps associated with surface states of colloidal CdSe nanoplatelets is reported. The traps have a cascade energy depletion mechanism via intrinsic excited states which cannot be detected by means of conventional thermally stimulated luminescence method. These cascade excited traps were characterized with the use of the original thermoluminescent technique. Energy diagram of nanoplatelets and related kinetic model were developed taking into account the trap excitation mechanism. According to the model density of surface states of the nanoplatelets was demonstrated to have two maxima at 100 and 280 meV. Физика и техника полупроводников, 2015, том 49, вып. 10