Ordered hybrid nanostructures for nanophotonics applications are fabricated by a novel approach via femtosecond laser melting of asymmetric metal-dielectric (Au/Si) nanoparticles created by lithographical methods. The approach allows selective reshaping of the metal components of the hybrid nanoparticles without affecting the dielectric ones and is applied for tuning of the scattering properties of the hybrid nanostructures in the visible range.

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The properties of n‐GaP/p‐Si interface as well as their influence on solar cell performance are studied for GaP layers grown by low‐temperature (380 °C) plasma‐enhanced atomic layer deposition (PE‐ALD). The influence of different plasma treatments and RF power values are explored. The increase of RF power leads to a growth transition from amorphous (a‐GaP) to microcrystalline GaP (μc‐GaP) with either amorphous‐GaP/Si or epitaxial‐GaP/Si interface, respectively. However, when continuous hydrogen plasma is used the amorphous‐GaP/Si interface exhibits better photovoltaic performance compared to the epitaxial one. Values of open circuit voltage, Voc = 0.45–0.55 V and internal quantum efficiencies, IQE > 0.9 are obtained for amorphous‐GaP/Si interfaces compared to Voc = 0.25–0.35 V and IQE < 0.45 for epitaxial‐GaP/Si interfaces. According to admittance spectroscopy and TEM studies the near‐surface (30–50 nm) area of the Si substrate is damaged during growth with high RF power of hydrogen plasma. A hole trap at the level of EV + (0.33 ± 0.02) eV is detected by admittance spectroscopy in this damaged Si area. The damage of Si is not observed by TEM when the deposition of the structures with epitaxial‐GaP/Si interface is realized by a modified process without hydrogen plasma indicating that the damage of the near‐surface area of Si is related to hydrogen plasma interaction.

An approach for epitaxial growth of GaP layers on Si substrates at low temperature (380°C) by plasma-enhanced atomic layer deposition (PEALD) is explored. A significant improvement of the crystalline properties of the GaP layers is obtained using additional in-situ Ar plasma treatment. The epitaxial growth for the first 20-30 nm of GaP on Si is demonstrated from transmission electron microscopy. Moreover, the use of in-situ Ar plasma treatment during the PEALD process allows one to increase the growth rate per cycle from 0.9±0.1 Å/cycle to 1.9±0.1 Å/cycle and reduce the RMS roughness from 3.76 nm to 1.88 nm. The effect of Ar plasma treatment on the electronic properties of the GaP/Si interface is studied by deep level transient spectroscopy (DLTS). A defect level at (0.33±0.03) eV below the conduction band is observed in the subsurface layer of Si for the GaP/Si structure grown under Ar plasma treatment. However, the defect response observed by DLTS vanishes after rapid thermal annealing at 500 ºC in nitrogen ambient.

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Nanowires represent numerous opportunities for nanoelectronics and sensorics, while metal contact fabrication makes the device development rather challenging. Here, we demonstrate that silicon (Si) nanowires deposited on interdigital metal contacts via simple drop casting exhibit an abrupt increase in conductivity upon exposure to ammonia vapors and aqueous solutions due to adsorption of the analyte species. To reduce the noise of the DC resistance measurements lacking ohmic conductivity, we exploit electronic impedance spectroscopy. The resistive response is found to be dependent on the ammonia content in vapor and liquid matter. The results demonstrate a detection limit of 4 μmol•L −1 (80 ppb), a sensitivity of 0.2% μmol −1 •l (0.01%•ppb −1 ), and applicability for the low-concentration detection of up to 400 μmol•L −1 (8 ppm) ammonia in aqueous solutions both directly and indirectly with a response rate of up to 0.43%•s −1 and a recovery rate of 0.31%•s −1 and show selectivity to oxidizing species. Thus, we demonstrate that the use of semiconductor nanowires in adsorption sensorics does not require the fabrication of ohmic contacts and present a simple fabrication protocol perspective for the development of highly sensitive room-temperature multi-environment sensors.

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One of hypotheses of atherosclerosis is based on a presumption that the zones prone to the development of atherosclerosis contain lysosomes which are characterized by enzyme deficiency and thus, are unable to dispose of lipoproteins. The present study was undertaken to investigate the characteristics and changes of lysosomes in the earliest stages of the development of atherosclerosis. Electron microscopic immunocytochemistry revealed that there were certain changes in the distribution of CD68 antigen in lysosomes along the ‘normal intima-initial lesion-fatty streak’ sequence. There were no significant changes found in the key mRNAs encoding for the components of endosome/lysosome compartment in initial atherosclerotic lesions, but in fatty streaks, the contents of EEA1 and Rab5a mRNAs were found to be diminished while the contents of CD68 and p62 mRNAs were increased, compared with the intact tissue. The study reinforces a view that changes occurring in lysosomes play a role in atherogenesis from the very earlier stages of the disease.