scholarly journals Atomic Layer Deposition Coated Filters in Catalytic Filtration of Gasification Gas

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 688
Author(s):  
Tyko Viertiö ◽  
Viivi Kivelä ◽  
Matti Putkonen ◽  
Johanna Kihlman ◽  
Pekka Simell
Keyword(s):  
Atomic Layer ◽  
Biomass Gasification ◽  
Optimal Conditions ◽  
Al2o3 Layer ◽  
Gas Cleaning ◽  
Catalytic Coating ◽  
Layer Deposition ◽  
Coating Methods ◽  
Tar Reforming ◽  
Stop Flow

Steel filter discs were catalytically activated by ALD, using a coating of supporting Al2O3 layer and an active NiO layer for gas cleaning. Prepared discs were tested for model biomass gasification and gas catalytic filtration to reduce or eliminate the need for a separate reforming unit for gasification gas tars and lighter hydrocarbons. Two different coating methods were tested. The method utilizing the stop-flow setting was shown to be the most suitable for the preparation of active and durable catalytic filters, which significantly decreases the amount of tar compounds in gasification gas. A pressure of 5 bar and temperatures of over 850 °C are required for efficient tar reforming. In optimal conditions, applying catalytic coating to the filter resulted in a seven-fold naphthalene conversion increase from 7% to 49%.

scholarly journals Fabrication of Ultra-High Aspect Ratio (>420:1) Al2O3 Nanotube Arraysby Sidewall TransferMetal Assistant Chemical Etching

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 378 ◽  
Author(s):  
Hailiang Li ◽  
Changqing Xie
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Chemical Etching ◽  
Atomic Layer ◽  
Nanotube Arrays ◽  
Al2o3 Layer ◽  
Practical Applications ◽  
Aspect Ratios ◽  
Layer Deposition

We report a robust, sidewall transfer metal assistant chemical etching scheme for fabricating Al2O3 nanotube arrays with an ultra-high aspect ratio. Electron beam lithography followed by low-temperature Au metal assisted chemical etching (MacEtch) is used to pattern high resolution, high aspect ratio, and vertical silicon nanostructures, used as a template. This template is subsequently transferred by an atomic layer deposition of the Al2O3 layer, followed by an annealing process, anisotropic dry etching of the Al2O3 layer, and a sacrificial silicon template. The process and characterization of the Al2O3 nanotube arrays are discussed in detail. Vertical Al2O3 nanotube arrays with line widths as small as 50 nm, heights of up to 21 μm, and aspect ratios up to 420:1 are fabricated on top of a silicon substrate. More importantly, such a sidewall transfer MacEtch approach is compatible with well-established silicon planar processes, and has the benefits of having a fully controllable linewidth and height, high reproducibility, and flexible design, making it attractive for a broad range of practical applications.

Durable superhydrophobic wool fabrics coating with nanoscale Al2O3 layer by atomic layer deposition

2015 ◽  
Vol 349 ◽  
pp. 876-879 ◽  
Author(s):  
Xingfang Xiao ◽  
Genyang Cao ◽  
Fengxiang Chen ◽  
Yunrong Tang ◽  
Xin Liu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Al2o3 Layer ◽  
Wool Fabrics ◽  
Layer Deposition

Electrical Properties of the La2O3/4H-SiC Interface Prepared by Atomic Layer Deposition Using La(iPrCp)3 and H2O

2006 ◽  
Vol 527-529 ◽  
pp. 1083-1086 ◽  
Author(s):  
Jeong Hyun Moon ◽  
Da Il Eom ◽  
Sang Yong No ◽  
Ho Keun Song ◽  
Jeong Hyuk Yim ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Atomic Layer Deposition ◽  
Leakage Current ◽  
Interfacial Layer ◽  
Atomic Layer ◽  
Mis Structure ◽  
Al2o3 Layer ◽  
Metal Insulator ◽  
Layer Deposition ◽  
Mis Structures

The La2O3 and Al2O3/La2O3 layers were grown on 4H-SiC by atomic layer deposition (ALD) method. The electrical properties of La2O3 on 4H-SiC were examined using metal-insulator-semiconductor (MIS) structures of Pt/La2O3(18nm)/4H-SiC and Pt/Al2O3(10nm)/La2O3(5nm)/4H-SiC. For the Pt/La2O3(18nm)/4H-SiC structure, even though the leakage current density was slightly reduced after the rapid thermal annealing at 500 oC, accumulation capacitance was gradually increased with increasing bias voltage due to a high leakage current. On the other hand, since the leakage current in the accumulation regime was decreased for the Pt/Al2O3/La2O3/4H-SiC MIS structure owing to the capped Al2O3 layer, the capacitance was saturated. But the saturation capacitance was strongly dependent on frequency, indicating a leaky interfacial layer formed between the La2O3 and SiC during the fabrication process of Pt/Al2O3(10nm)/ La2O3(5nm)/ 4H-SiC structure.

Barrier properties of plastic films coated with an Al2O3 layer by roll-to-toll atomic layer deposition

2014 ◽  
Vol 550 ◽  
pp. 164-169 ◽  
Author(s):  
Terhi Hirvikorpi ◽  
Risto Laine ◽  
Mika Vähä-Nissi ◽  
Väinö Kilpi ◽  
Erkki Salo ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Barrier Properties ◽  
Al2o3 Layer ◽  
Plastic Films ◽  
Layer Deposition

Effect of Post Oxide Annealing on the Electrical and Interface 4H-SiC/Al2O3 MOS Capacitors

2018 ◽  
Vol 924 ◽  
pp. 486-489 ◽  
Author(s):  
Muhammad I. Idris ◽  
Nick G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
Atomic Layer Deposition ◽  
Electric Field ◽  
Annealing Temperature ◽  
Atomic Layer ◽  
Al2o3 Layer ◽  
Mos Capacitors ◽  
Oxide Breakdown ◽  
Layer Deposition ◽  
The Stability

This paper reports on the effect of forming gas annealing on the C-V characteristics and stability of Al2O3/SiC MOS capacitors deposited by atomic layer deposition, (ALD). C-V and I-V measurements were performed to assess the quality of the Al2O3 layer and the Al2O3/SiC interface. In comparison to as-deposited sample, the post oxide annealing (POA) in forming gas at high temperatures has improved the stability of C-V characteristic and the properties at the interface of Al2O3/SiC capacitors. However, the oxide capacitance and oxide breakdown electric field degrade with increased annealing temperature. The results provide indications to improve the performance of Al2O3/SiCcapacitors 4H-SiC devices by optimizing the annealing temperature.

scholarly journals Investigations on the Electrochemical Atomic Layer Growth of Bi2Se3 and the Surface Limited Deposition of Bismuth at the Silver Electrode

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1426 ◽  
Author(s):  
Walter Giurlani ◽  
Andrea Giaccherini ◽  
Nicola Calisi ◽  
Giovanni Zangari ◽  
Emanuele Salvietti ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Ultrathin Films ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
Layer Growth ◽  
Electrochemical Studies ◽  
Optimal Conditions ◽  
X Ray ◽  
Layer Deposition ◽  
Controlled Deposition

The Electrochemical Atomic Layer Deposition (E-ALD) technique is used for the deposition of ultrathin films of bismuth (Bi) compounds. Exploiting the E-ALD, it was possible to obtain highly controlled nanostructured depositions as needed, for the application of these materials for novel electronics (topological insulators), thermoelectrics and opto-electronics applications. Electrochemical studies have been conducted to determine the Underpotential Deposition (UPD) of Bi on selenium (Se) to obtain the Bi2Se3 compound on the Ag (111) electrode. Verifying the composition with X-ray Photoelectron Spectroscopy (XPS) showed that, after the first monolayer, the deposition of Se stopped. Thicker deposits were synthesized exploiting a time-controlled deposition of massive Se. We then investigated the optimal conditions to deposit a single monolayer of metallic Bi directly on the Ag.

scholarly journals Investigation on Threshold Voltage Adjustment of Threshold Switching Devices with HfO2/Al2O3 Superlattice on Transparent ITO/Glass Substrate

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 525
Author(s):  
Yejoo Choi ◽  
Jaemin Shin ◽  
Seungjun Moon ◽  
Changhwan Shin
Keyword(s):  
Atomic Layer Deposition ◽  
Barrier Height ◽  
Threshold Voltage ◽  
Glass Substrate ◽  
Atomic Layer ◽  
Al2o3 Layer ◽  
Cross Point ◽  
Threshold Switching ◽  
Layer Deposition ◽  
Ito Glass

Threshold voltage adjustment in threshold switching (TS) devices with HfO2/Al2O3 superlattice (by means of changing the cycle ratio of HfO2 to Al2O3 in atomic layer deposition) is investigated to implement a transparent cross-point array. TS devices with different cycle ratios (i.e., 3:1, 3:2, and 3:3) were fabricated and studied. The threshold voltage of the devices was increased from 0.9 V to 3.2 V, as the relative contents of Al2O3 layer in the superlattice were increased. At the same time, it is demonstrated that the off-resistance values of the devices were enhanced from 2.6 × 109 to 6 × 1010 Ω as the atomic layer deposition (ALD) cycle ratio of HfO2 to Al2O3 layer was adjusted from 3:1 to 3:3. However, the hold voltage and the on-current values were almost identical for the three devices. These results can be understood using the larger barrier height of Al2O3 layer than that of HfO2 layer.

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