scholarly journals Passivated Porous Silicon Membranes and Their Application to Optical Biosensing

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 10
Author(s):  
Clara Whyte Ferreira ◽  
Roselien Vercauteren ◽  
Laurent A. Francis
Keyword(s):  
Porous Silicon ◽  
Hafnium Oxide ◽  
Chemical Properties ◽  
Atomic Layer ◽  
Bacterial Lysate ◽  
Optical Biosensing ◽  
Mesoporous Silicon ◽  
Layer Deposition ◽  
Optical Probing ◽  
Silicon Membranes

A robust fabrication method for stable mesoporous silicon membranes using standard microfabrication techniques is presented. The porous silicon membranes were passivated through the atomic layer deposition of different metal oxides, namely aluminium oxide Al2O3, hafnium oxide HfO2 and titanium oxide TiO2. The fabricated membranes were characterized in terms of morphology, optical properties and chemical properties. Stability tests and optical probing noise level determination were also performed. Preliminary results using an Al2O3 passivated membranes for a biosensing application are also presented for selective optical detection of Bacillus Cereus bacterial lysate. The biosensor was able to detect the bacterial lysate, with an initial bacteria concentration of 106 colony forming units per mL (CFU/mL), in less than 10 min.

scholarly journals Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1987 ◽  
Author(s):  
Mykola Pavlenko ◽  
Valerii Myndrul ◽  
Gloria Gottardi ◽  
Emerson Coy ◽  
Mariusz Jancelewicz ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Porous Silicon ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
Visible Range ◽  
Optical Biosensing ◽  
X Ray ◽  
Layer Deposition

In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a “shoulder-shape” emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.

scholarly journals Preparation of Hafnium Oxide Thin Films grown by Atomic Layer Deposition

2005 ◽  
Vol 15 (4) ◽  
pp. 275-280
Author(s):  
Hie-Chul Kim ◽  
Min-Wan Kim ◽  
Hyung-Su Kim ◽  
Hyug-Jong Kim ◽  
Woo-Keun Sohn ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Hafnium Oxide ◽  
Atomic Layer ◽  
Oxide Thin Films ◽  
Layer Deposition

Properties of hafnium oxide films grown by atomic layer deposition from hafnium tetraiodide and oxygen

2002 ◽  
Vol 92 (10) ◽  
pp. 5698-5703 ◽  
Author(s):  
Kaupo Kukli ◽  
Mikko Ritala ◽  
Jonas Sundqvist ◽  
Jaan Aarik ◽  
Jun Lu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Hafnium Oxide ◽  
Oxide Films ◽  
Atomic Layer ◽  
Layer Deposition

Insights into the passivation effect of atomic layer deposited hafnium oxide for efficiency and stability enhancement in organic solar cells

2018 ◽  
Vol 6 (30) ◽  
pp. 8051-8059 ◽  
Author(s):  
Ermioni Polydorou ◽  
Martha Botzakaki ◽  
Charalampos Drivas ◽  
Kostas Seintis ◽  
Ilias Sakellis ◽  
...  
Keyword(s):  
Solar Cells ◽  
Atomic Layer Deposition ◽  
Organic Solar Cells ◽  
Hafnium Oxide ◽  
Atomic Layer ◽  
Layer Deposition ◽  
Stability Enhancement

Atomic layer deposition of HfO2 significantly increases the efficiency and prolongs the lifetime of organic solar cells.

Design, Simulation and Testing of High Density, High Current Micro-machined Embedded Capacitors

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 000515-000534
Author(s):  
Aubrey Beal ◽  
C. Stevens ◽  
T. Baginski ◽  
M. Hamilton ◽  
R. Dean
Keyword(s):  
Integrated Circuits ◽  
Hafnium Oxide ◽  
Implementation Strategies ◽  
Atomic Layer ◽  
High Density ◽  
Embedded Capacitors ◽  
Passive Devices ◽  
Layer Deposition ◽  
High K ◽  
High K Materials

Due to increasing speed, density and number of signal paths in integrated circuits, motivations for high density capacitors capable of quickly sourcing large amounts of current have led to many design and fabrication investigations. This work outlines continued efforts to achieve devices which meet these stringent requirements and are compatible with standard silicon fabrication processes as well as silicon interposer technologies. Previous work has been further developed resulting in devices exhibiting greater capacitance values by employing geometries which maximize surface area. The Atomic Layer Deposition (ALD) of thin layered high K materials, such as Hafnium Oxide, as opposed to previous silicon-dioxide based devices effectively increased the capacitance per unit area of the structures. This paper outlines the design, fabrication, and testing of high density micro-machined embedded capacitors capable of quickly sourcing (i.e. risetimes greater than 100A/nsec) high currents (i.e. greater than 100A). These devices were successfully simulated then tested using a standard ringdown procedure. Generally, the resulting device characterization found during testing stages strongly correlates to the expected simulated device behavior. Subsequent descriptions and design challenges encountered during fabrication, testing and integration of these passive devices are outlined, as well as potential device integration and implementation strategies for use in silicon interposers. The modification and revision of several device generations is documented and presented. Increased device capacitive density, maximized current capabilities and minimized effects of series inductance and resistance are presented. These resulting thin, capacitive structures exhibit compatibility with Si interposer technology.

Role of Mesoporous TiO2 Surface States and Metal Oxide Treatment on Charge Transport of Dye Sensitized Solar Cells

2010 ◽  
Vol 1270 ◽  
Author(s):  
Mariyappan Shanmugam ◽  
Braden Bills ◽  
Mahdi Farrokh Baroughi
Keyword(s):  
Activation Energy ◽  
Dark Current ◽  
Hafnium Oxide ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Surface States ◽  
Atomic Layer ◽  
Dye Sensitized ◽  
Layer Deposition ◽  
Atomic Layer Deposition Method

AbstractPhotovoltaic performance of dye sensitized solar cell (DSSC) was enhanced by 19 and 69 % compared to untreated DSSC by treating the nanoporous titanium dioxide (TiO2) by ultra thin Aluminum oxide (Al2O3) and Hafnium oxide (HfO2) grown by atomic layer deposition method. Activation energy of dark current, obtained from the temperature dependent current-voltage (I-V-T), of the untreated DSSC was 1.03 eV on the other hand the DSSCs with Al2O3 and HfO2 surface treatment showed 1.27 and 1.31 eV respectively. A significant change in the activation energy of dark current, over 0.24 eV for Al2O3 treatment and 0.28 eV in case of HfO2 treatment, suggest that density and activity of surface states on nanoporous TiO2 was suppressed by ALD grown metal oxides to result improved photovoltaic performance. Further the enhanced DSSC performance was confirmed by external quantum efficiency measurement in the wavelength range of 350-750 nm.

scholarly journals Atomic Layer Deposition for Preparation of Highly Efficient Catalysts for Dry Reforming of Methane

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 266 ◽  
Author(s):  
Soong Kim ◽  
Byeong Cha ◽  
Shahid Saqlain ◽  
Hyun Seo ◽  
Young Kim
Keyword(s):  
Atomic Layer Deposition ◽  
Heterogeneous Catalysts ◽  
Chemical Properties ◽  
Atomic Layer ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
High Catalytic Activity ◽  
Term Operation ◽  
Layer Deposition

In this article, the structural and chemical properties of heterogeneous catalysts prepared by atomic layer deposition (ALD) are discussed. Oxide shells can be deposited on metal particles, forming shell/core type catalysts, while metal nanoparticles are incorporated into the deep inner parts of mesoporous supporting materials using ALD. Both structures were used as catalysts for the dry reforming of methane (DRM) reaction, which converts CO2 and CH4 into CO and H2. These ALD-prepared catalysts are not only highly initially active for the DRM reaction but are also stable for long-term operation. The origins of the high catalytic activity and stability of the ALD-prepared catalysts are thoroughly discussed.

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