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Si/ZnO nanorods with Ag nanoparticles/AZO heterostructures in PV applications

Gwóźdź K., Płaczek-Popko E., Gumienny Z., Zielony E., Pietruszka R., Witkowski B. S., Wachnicki Ł., Gierałtowska S., Godlewski M., Chang L. B.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2016

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Vol. 64, nr 3

529--533

EN

Our studies focus on test structures for photovoltaic applications based on zinc oxide nanorods grown using a low-temperature hydrothermal method on a p-type silicon substrate. The nanorods were covered with silver nanoparticles of two diameters – 20–30 nm and 50–60 nm – using a sputtering method. Scanning electron microscopy (SEM) micrographs showed that the deposited nanoparticles had the same diameters. The densities of the nanorods were obtained by means of atomic force microscope (AFM) images. SEM images and Raman spectroscopy confirmed the hexagonal wurtzite structure of the nanorods. Photoluminescence measurements proved the good quality of the samples. Afterwards an atomic layer deposition (ALD) method was used to grow ZnO:Al (AZO) layer on top of the nanorods as a transparent electrode and ohmic Au contacts were deposited onto the silicon substrate. For the solar cells prepared in that manner the current-voltage (I-V) characteristics before and after the illumination were measured and their basic performance parameters were determined. It was found that the spectral characteristics of a quantum efficiency exhibit an increase for short wavelengths and this behavior has been linked with the plasmonic effect.

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RF Magnetron Sputtering Coating Of Hydroxyapatite On Alkali Solution Treated Titanate Nanorods

Lee K., Shin G.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1319--1322

EN

Hydroxyapatite (HA) is a material with outstanding biocompatibility. It is chemically similar to natural bone tissue, and has therefore been favored for use as a coating material for dental and orthopedic implants. In this study, RF magnetron sputtering was applied for HA coating. And Alkali treatment was performed in a 5 M NaOH solution at 60°C. The coated HA thin film was heat-treated at a range of temperatures from 300 to 600°C. The morphological characterization and crystal structures of the coated specimens were then obtained via FE-SEM, XRD, and FT-IR. The amorphous thin film obtained on hydrothermally treated nanorods transformed into a crystalline thin film after the heat treatment. The change in the phase transformation, with an enhanced crystallinity, showed a reduced wettability. The hydrothermally treated nanorods with an amorphous thin film, on the other hand, showed an outstanding wettability. The HA thin film perpendicularly coated the nanorods in the upper and inner parts via RF magnetron sputtering, and the FT-IR results confirmed that the molecular bonding of the coated film had an HA structure.

3

Large-Area Sodium Titanate Nanorods Formed On Titanium Surface Via NaOH Alkali Treatment

Lee K., Yoo D.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1371--1374

EN

Ti surfaces covered with large sodium titanate nanorods act as efficient electrodes for energy conversion and environmental applications. In this study, sodium titanate nanorod films were prepared on a Ti substrate in a 5M NaOH aqueous solution followed by heat treatment. The morphological characterization and the crystal structures of the sodium titanate nanorods were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Thin amorphous sodium titanate layers formed during the alkali-treatment, and sodium titanate nanorods were obtained after heat treatment at a temperature of 700°C. The sodium titanate nanorods obtained at this temperature had a thickness of about 80 nm and a length of 1 μm. The crystal structure of the sodium titanate was identified with the use of Na2Ti5O11. The nanorods were agglomerated at a temperature above 900°C, and large-scale nanorods formed on the Ti surface, which may be used for electrodes for energy conversion applications.

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Synthesis and characterization of SiO2 and SiC micro/nanostructures

Zhu G., Zou X. P., Cheng J., Su Y.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 3

727-734

EN

Silica-based nanowires, straight nanorods, straight Y-shaped słlica nanorods, flower-like microstructures, and SiC/Si02 core-shell coaxial nanocables have been generated through a simple thermal evaporation method. The synthesized samples were characterized by means ot" scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and Raman spectrum. Generated silica nanowires with a diameter of about lOOnm and length of up to several tens of micrometers, straight silica nanorods and Y-shaped nanorods with a diameter about 50-200nm, and novel flower-like silica microstructures all are amorphous and consist only of silicon oxide, and have a neat smooth surface. Generated SiC/SiO? core-shell coaxial nanocables have a crystalline core and a surrounding amorphous layer. The results show that the present method should be possible to synthesis various micro/nanostructures under appropriate experimental conditions. These nanostructures may find applications as building blocks in nanomechanical or nanoelectronic devices.

PL

Nanodruty na podłożu Si02, proste (straight) nanopręty, krzemionkowe nanopręty w kształcie litery Y, mikrostruktury kwiatowe, SiC/Si02 rdzeniowo-powłokowe kable koncentryczne zostały wytworzone przy zastosowaniu prostej metody odparowania cieplnego. Poddane syntezie próbki scharakteryzowano przy pomocy skaningowej mikroskopii elektronowej, transmisyjnej mikroskopii elektonowej, wysoko rozdzielczej transmisyjnej mikroskopii elektronowej, rentgenospektroskopii z dyspresją energii widma oraz widmaRaman'a. Wytworzone krzemionkowe mikrodruty o średnicy około lOOnm oraz długości dochodzącej do kilkudziesięciu mikrometyrów, proste (straight) krzeminokowe nanopręty oraz nanopręty w kształcie litery Y o średnicy około 50-200nm jak również krzemionkowe mikrostruktury kwiatowe są wszystkie amorficzne i składają się jedynie z tlenku krzemowego wykazując uporządkowaną, gładką powierzchnię. Wytworzone SiC/SiOi rdzeniowo-powłokowe kable koncentryczne posiadają rdzeń krystaliczny oraz otaczają go warstwa amorficzną. Wyniki wykazują, że metoda o której mowa może być zastosowana do syntezy różnych mikro/nanostruktur przy zachowaniu odpowiednich reżimów eksperymentalnych. Nanostruktury, o których mowa, mogą znaleźć zastosowanie jako bloki konstrukcyjne w urządzeniach mechanicznych i nanoelektrycznych.