Ordered and Parallel Niobium Oxide Nano-Tubes Fabricated using Atomic Layer Deposition in Anodic Alumina Templates

AbstractAmorphous niobium oxide (Nb2O5) nano-tubes were fabricated inside anodic alumina templates using atomic layer deposition (ALD). The nanoporous templates were in-house fabricated anodic alumina membranes having an inter-pore distance of about 100 nm with pores lengths of 2 µm. The pores were parallel and well ordered in a hexagonal pattern. Atomic layer deposition was performed using gas pulses of niobium iodide (NbI5) and oxygen separated by purging pulses of argon. By employing long gas pulses (30 s) it was possible to get coherent and amorphous Nb2O5 films conformally covering the pore-walls of the alumina template. The outer diameter of the nano-tubes was tailored between 40 and 80 nm by using alumina templates with different pore sizes. By using template membranes with pores not opened in the bottom, nano-tubes with one side closed could be fabricated. Free-standing, and still parallel, nano-tubes could be obtained by selectively etching away the alumina template using phosphoric acid. Using the above mentioned procedure it was possible to fabricate unsurpassed parallel niobium oxide nano-tubes of equal length, diameter and wall-thickness, ordered in a perfect hexagonal pattern. The samples were analysed using high resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), electron diffraction and x-ray fluorescence spectroscopy (XRFS).

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Electrostatic Supercapacitors by Atomic Layer Deposition on Nanoporous Anodic Alumina Templates for Environmentally Sustainable Energy Storage

Coatings ◽

10.3390/coatings8110403 ◽

2018 ◽

Vol 8 (11) ◽

pp. 403 ◽

Cited By ~ 4

Author(s):

Luis Fernández-Menéndez ◽

Ana González ◽

Víctor Vega ◽

Víctor de la Prida

Keyword(s):

Atomic Layer Deposition ◽

Silicon Dioxide ◽

Atomic Layer ◽

Dielectric Materials ◽

Anodic Alumina ◽

Layer By Layer ◽

Nanoporous Anodic Alumina ◽

Low Leakage ◽

Layer Deposition ◽

Anodic Alumina Templates

In this work, the entire manufacturing process of electrostatic supercapacitors using the atomic layer deposition (ALD) technique combined with the employment of nanoporous anodic alumina templates as starting substrates is reported. The structure of a usual electrostatic capacitor, which comprises a top conductor electrode/the insulating dielectric layer/and bottom conductor electrode (C/D/C), has been reduced to nanoscale size by depositing layer by layer the required materials over patterned nanoporous anodic alumina membranes (NAAMs) by employing the ALD technique. A thin layer of aluminum-doped zinc oxide, with 3 nm in thickness, is used as both the top and bottom electrodes’ material. Two dielectric materials were tested; on the one hand, a triple-layer made by a successive combination of 3 nm each layers of silicon dioxide/titanium dioxide/silicon dioxide and on the other hand, a simple layer of alumina, both with 9 nm in total thickness. The electrical properties of these capacitors are studied, such as the impedance and capacitance dependences on the AC frequency regime (up to 10 MHz) or capacitance (180 nF/cm2) on the DC regime. High breakdown voltage values of 60 V along with low leakage currents (0.4 μA/cm2) are also measured from DC charge/discharge RC circuits to determine the main features of the capacitors behavior integrated in a real circuit.

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Free-Standing Porous Anodic Alumina Templates for Atomic Layer Deposition of Highly Ordered TiO2Nanotube Arrays on Various Substrates

The Journal of Physical Chemistry C ◽

10.1021/jp076949q ◽

2007 ◽

Vol 112 (1) ◽

pp. 69-73 ◽

Cited By ~ 61

Author(s):

Lee Kheng Tan ◽

Maria A. S. Chong ◽

Han Gao

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Anodic Alumina ◽

Porous Anodic Alumina ◽

Free Standing ◽

Layer Deposition ◽

Anodic Alumina Templates

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Atomic Layer Deposition of Lithium–Nickel–Silicon Oxide Cathode Material for Thin-Film Lithium-Ion Batteries

Energies ◽

10.3390/en13092345 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2345

Author(s):

Maxim Maximov ◽

Denis Nazarov ◽

Aleksander Rumyantsev ◽

Yury Koshtyal ◽

Ilya Ezhov ◽

...

Keyword(s):

Thin Film ◽

Electron Microscopy ◽

Atomic Layer Deposition ◽

Lithium Ion Batteries ◽

Silicon Oxide ◽

Lithium Ion ◽

Atomic Layer ◽

X Ray ◽

Layer Deposition ◽

Nickel Silicon

Lithium nickelate (LiNiO2) and materials based on it are attractive positive electrode materials for lithium-ion batteries, owing to their large capacity. In this paper, the results of atomic layer deposition (ALD) of lithium–nickel–silicon oxide thin films using lithium hexamethyldisilazide (LiHMDS) and bis(cyclopentadienyl) nickel (II) (NiCp2) as precursors and remote oxygen plasma as a counter-reagent are reported. Two approaches were studied: ALD using supercycles and ALD of the multilayered structure of lithium oxide, lithium nickel oxide, and nickel oxides followed by annealing. The prepared films were studied by scanning electron microscopy, spectral ellipsometry, X-ray diffraction, X-ray reflectivity, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction. The pulse ratio of LiHMDS/Ni(Cp)2 precursors in one supercycle ranged from 1/1 to 1/10. Silicon was observed in the deposited films, and after annealing, crystalline Li2SiO3 and Li2Si2O5 were formed at 800 °C. Annealing of the multilayered sample caused the partial formation of LiNiO2. The obtained cathode materials possessed electrochemical activity comparable with the results for other thin-film cathodes.

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