Fabrication of Thin Film Titania with Nanopores, Nanopoles, and Nanopipes by Nanoporous Alumina Template

We demonstrate the formation of thin film titania (TiO2) with a dense array of nanopores, nanopoles, and nanopipes. The heights of pores, poles, and pipes were approximately 130 nm, 180 nm, and 200 nm, respectively. The aspect ratios of these three structures were approximated between 2 and 3. In order to obtain titania thin films, a nanoporous alumina (Al2O3) template was fabricated by performing a two-step anodization process. The spin-coated titania films were uniformly patterned by a nanoimprinting lithography technique with a textured poly(methyl methacrylate) (PMMA) mold or nanoporous alumina template. The titania films are very useful for solar cells, photocatalytic and sensing applications, in which nano-structuring of surfaces with controlled dimensions is vital.

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Nanoporous Titania by Embossing with PMMA Nanopoles Made from Nanoporous Alumina Template

Materials Science Forum ◽

10.4028/www.scientific.net/msf.544-545.1017 ◽

2007 ◽

Vol 544-545 ◽

pp. 1017-1020 ◽

Cited By ~ 3

Author(s):

Hyun Jung Her ◽

Jung Min Kim ◽

Yun Soo Lim ◽

Jae Wan Kim ◽

Y.J. Choi ◽

...

Keyword(s):

Indium Tin Oxide ◽

Aluminum Surface ◽

Dense Array ◽

Alumina Template ◽

Nanoporous Alumina ◽

Titania Films ◽

Highly Uniform ◽

Photocatalytic Applications ◽

Nanostructured Titania ◽

Propanol Solution

We produced highly uniform nanoporous thin films of the dense array of titania (TiO2) pores of 70~80 nm in diameter with nanoimprinting method. Titania in HCl and 2-propanol solution was coated on an indium tin oxide (ITO) surface and embossed with an array of PMMA nanopoles which was produced using a nanoporous alumina (Al2O3) template. Two-step anodization was introduced to produce highly uniform and dense nanopores on the aluminum surface. The polymethyl methacrylate (PMMA) was poured onto and infiltrated into the nanoporous alumina surface which was heated at 150 oC. The alumina nanopores and aluminum plate were removed by wet-etching leaving an array of PMMA nanopoles. These highly uniform nanostructured titania films will be very useful for photovoltaic and photocatalytic applications where nanostructuring of surface with controlled dimensions are essential.

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X-ray Photoelectron Spectroscopy Analysis of Chitosan–Graphene Oxide-Based Composite Thin Films for Potential Optical Sensing Applications

Polymers ◽

10.3390/polym13030478 ◽

2021 ◽

Vol 13 (3) ◽

pp. 478

Author(s):

Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽

Yap Wing Fen ◽

Silvan Saleviter ◽

Narong Chanlek ◽

Hideki Nakajima ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Functional Group ◽

Optical Sensing ◽

Composite Thin Films ◽

Cobalt Ions ◽

X Ray ◽

Sensing Applications

In this study, X-ray photoelectron spectroscopy (XPS) was used to study chitosan–graphene oxide (chitosan–GO) incorporated with 4-(2-pyridylazo)resorcinol (PAR) and cadmium sulfide quantum dot (CdS QD) composite thin films for the potential optical sensing of cobalt ions (Co2+). From the XPS results, it was confirmed that carbon, oxygen, and nitrogen elements existed on the PAR–chitosan–GO thin film, while for CdS QD–chitosan–GO, the existence of carbon, oxygen, cadmium, nitrogen, and sulfur were confirmed. Further deconvolution of each element using the Gaussian–Lorentzian curve fitting program revealed the sub-peak component of each element and hence the corresponding functional group was identified. Next, investigation using surface plasmon resonance (SPR) optical sensor proved that both chitosan–GO-based thin films were able to detect Co2+ as low as 0.01 ppm for both composite thin films, while the PAR had the higher binding affinity. The interaction of the Co2+ with the thin films was characterized again using XPS to confirm the functional group involved during the reaction. The XPS results proved that primary amino in the PAR–chitosan–GO thin film contributed more important role for the reaction with Co2+, as in agreement with the SPR results.

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Al1-x ScxN Thin Film Structures for Pyroelectric Sensing Applications

MRS Advances ◽

10.1557/adv.2016.510 ◽

2016 ◽

Vol 1 (39) ◽

pp. 2711-2716 ◽

Cited By ~ 2

Author(s):

V. Vasilyev ◽

J. Cetnar ◽

B. Claflin ◽

G. Grzybowski ◽

K. Leedy ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Pyroelectric Coefficient ◽

X Ray Diffraction ◽

Ir Detectors ◽

Pyroelectric Properties ◽

X Ray ◽

Sensing Applications ◽

Pyroelectric Material ◽

Deposited Films

ABSTRACTAlN thin film structures have many useful and practical piezoelectric and pyroelectric properties. The potential enhancement of the AlN piezo- and pyroelectric constants allows it to compete with more commonly used materials. For example, combination of AlN with ScN leads to new structural, electronic, and mechanical characteristics, which have been reported to substantially enhance the piezoelectric coefficients in solid-solution AlN-ScN compounds, compared to a pure AlN-phase material.In our work, we demonstrate that an analogous alloying approach results in considerable enhancement of the pyroelectric properties of AlN - ScN composites. Thin films of ScN, AlN and Al1-x ScxN (x = 0 – 1.0) were deposited on silicon (004) substrates using dual reactive sputtering in Ar/N2 atmosphere from Sc and Al targets. The deposited films were studied and compared using x-ray diffraction, XPS, SEM, and pyroelectric characterization. An up to 25% enhancement was observed in the pyroelectric coefficient (Pc = 0.9 µC /m2K) for Sc1-xAlxN thin films structures in comparison to pure AlN thin films (Pc = 0.71 µC/m2K). The obtained results suggest that Al1-x ScxN films could be a promising novel pyroelectric material and might be suitable for use in uncooled IR detectors.

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Growth, Structural and Mechanical Characterization and Reliability of Chemical Vapor Deposited Co and Co3O4 Thin Films as Candidate Materials for Sensing Applications

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.495.108 ◽

2011 ◽

Vol 495 ◽

pp. 108-111 ◽

Cited By ~ 2

Author(s):

Vasiliki P. Tsikourkitoudi ◽

Elias P. Koumoulos ◽

Nikolaos Papadopoulos ◽

Costas A. Charitidis

Keyword(s):

Thin Film ◽

Thin Films ◽

Elastic Modulus ◽

Data Storage ◽

Mechanical Stability ◽

Chemical Vapor ◽

Magnetic Sensors ◽

Functional Coatings ◽

Sensing Applications ◽

Chemical Vapor Deposited

The adhesion and mechanical stability of thin film coatings on substrates is increasingly becoming a key issue in device reliability as magnetic and storage technology driven products demand smaller, thinner and more complex functional coatings. In the present study, chemical vapor deposited Co and Co3O4thin films on SiO2and Si substrates are produced, respectively. Chemical vapor deposition is the most widely used deposition technique which produces thin films well adherent to the substrate. Co and Co3O4thin films can be used in innovative applications such as magnetic sensors, data storage devices and protective layers. The produced thin films are characterized using nanoindentation technique and their nanomechanical properties (hardness and elastic modulus) are obtained. Finally, an evaluation of the reliability of each thin film (wear analysis) is performed using the hardness to elastic modulus ratio in correlation to the ratio of irreversible work to total work for a complete loading-unloading procedure.

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Effect of Anodizing Voltage on Anodic Titanium Dioxide (ATO) Growth Based on an Ethylene Glycol Solution Containing NH4F

Materials Science Forum ◽

10.4028/www.scientific.net/msf.872.147 ◽

2016 ◽

Vol 872 ◽

pp. 147-151

Author(s):

Chayangkoon Mangkornkarn ◽

Benjarong Samransuksamer ◽

Mati Horprathum ◽

Pitak Eiamchai ◽

Apiluck Eiad-Ua ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Titanium Dioxide ◽

Surface Morphology ◽

Ethylene Glycol ◽

Applied Voltage ◽

Base Material ◽

Dc Magnetron Sputtering ◽

Anodization Process ◽

Glycol Solution

We reported on the influence of applied voltage on the surface morphology of anodic titanium dioxide (ATO) thin films. At first, titanium (Ti) thin films were prepared by DC-magnetron sputtering for use as a base material in the anodization process. The titanium dioxide (TiO2) nanoporous ATO was fabricated by the anodization process from the Ti thin film, with different applied voltages from 20 V to 60 V in an electrolyte based on an ethylene glycol containing NH4F. Pore size distribution of ATO thin films can be varied from 20-50 nm by increasing the applied voltage, while the thickness of the film also increases. In addition, to observe the effect of time, the optimal condition of anodizing voltage was studied by increasing the anodizing time. The results clearly showed the nanoporous ATO over the films and the thickness of the nanoporous ATO is approximately 260 nm.

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Optimization of piezoelectric MEMS process on Sr and La co-doped PZT thin films

Journal of Advanced Dielectrics ◽

10.1142/s2010135x20500101 ◽

2020 ◽

Vol 10 (04) ◽

pp. 2050010

Author(s):

M. Kathiresan ◽

Jain Jose ◽

E. Varadarajan ◽

R. Ramesh ◽

V. Natarajan ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Lead Zirconate Titanate ◽

Etching Rate ◽

Dry Etching ◽

Mems Devices ◽

Pzt Thin Films ◽

Sensing Applications ◽

Piezoelectric Mems ◽

Co Doped

Doped lead–zirconate–titanate (PZT) thin films are preferred for the development of micro–electro–mechanical systems (MEMS)-based acoustic sensors because of their inherent higher dielectric and piezoelectric coefficients. Patterning process is used to develop such MEMS devices which is highly complex even for undoped PZT thin films; therefore, the problem is further cumbersome for doped PZT thin films due to the presence of added dopant elements and their associated chemistry. This paper presents patterning of strontium (Sr) and lanthanum (La) co-doped PZT thin film (PSLZT) deposited on platinized silicon substrate using wet and dry etching processes for fabricating a diaphragm structure with thickness of 15–25[Formula: see text][Formula: see text]m and diameter of 1.4–2[Formula: see text]mm, suitable for acoustic sensing applications. The effects of various etching conditions have been studied and the results are reported. It is found that the dry etching is the most suited process for realizing the piezoelectric MEMS structure due to its higher etching resolution. An appreciable etching rate of 260–270[Formula: see text]nm/min with smooth vertical sidewalls is achieved. The silicon diaphragm with patterned PSLZT thin film is found to retain more than 80% of its dielectric and piezoelectric coefficients and has a resonance of 1.43[Formula: see text]MHz.

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Interfacial Mismatch and Interface Structure of Epitaxial Pb(Mg1/3Nb2/3)O3 (90%)- PbTiO3 (10%) Relaxor Thin Films

Microscopy and Microanalysis ◽

10.1017/s1431927600034802 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 462-463

Author(s):

G. Y. Yang ◽

V. Nagarajan ◽

Z. L. Wang ◽

Y. H. Li ◽

R. Ramesh

Keyword(s):

Thin Film ◽

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Interface Structure ◽

Relaxor Ferroelectrics ◽

Dielectric Constants ◽

Ion Milling ◽

Sensing Applications ◽

Transmission Electron

Pb(Mg1/3Nb2/3)O3 (PMN)- and its solid solution with PbTiO3 (PT) is one of the lead-based relaxor ferroelectrics and has been the most widely studied materials because of their high dielectric constants and high electrostrictive coefficients. The potential impact of the thin film ferroelectric relaxors in the integrated actuators and sensing applications has stimulated research on the growth and characterization of thin films. Thin films have been made by pulsed-laser deposition (PLD), sol-gel and metalrganic chemical-vapor deposition. It is known that electrical properties may be strongly influenced by the microstructure of films and the interface structures between different phase in such heterostructure systems. In this paper, we report the investigation of interfacial mismatch and interface structure of epitaxial Pb(Mg1/3Nb2/3)O3 (90%)- PbTiO3 (10%) relaxor thin film by high resolution transmission electron microscopy (HRTEM).Thin film capacitors of Pb(Mg1/3Nb2/3)O3 (90%) - PbTiO3 (10%) (PMN-PT) were grown by PLD on (100)-oriented LaA1O3 (LAO) substrates. La0.5Sr0.5CoO3 (LSCO) layer was deposited as electrode. Cross-sectional transmission electron microscopy samples were prepared following the traditional procedures including cutting, gluing, polishing and ion milling.

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Organic thin-film transistors fabricated using a slot-die-coating process and related sensing applications

RSC Advances ◽

10.1039/c6ra18545b ◽

2016 ◽

Vol 6 (103) ◽

pp. 101613-101621 ◽

Cited By ~ 8

Author(s):

Byoungchoo Park ◽

In-Gon Bae ◽

O. Eun Kwon ◽

Hong Goo Jeon

Keyword(s):

Thin Film ◽

Thin Films ◽

Thin Film Transistors ◽

Polymer Binder ◽

Organic Thin Film Transistors ◽

Coating Process ◽

Organic Thin Film ◽

Sensing Applications ◽

Semiconductor Thin Films ◽

Slot Die

We herein present the results of a study involving the fabrication of semiconductor thin films for organic thin-film transistors composed of a small molecular TIPS-PEN composite blended with a polymer binder of PaMS, i.e., TIPS-PEN:PaMS.

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Gas-Sensing Property Evaluation of Reactively Sputtered Chromium Oxide Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.55-57.285 ◽

2008 ◽

Vol 55-57 ◽

pp. 285-288 ◽

Cited By ~ 1

Author(s):

C. Oros ◽

Anurat Wisitsoraat ◽

Pichet Limsuwan ◽

M. Horpathum ◽

V. Patthanasettakul ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Metal Oxide ◽

Chromium Oxide ◽

Flow Rate ◽

Gas Sensing ◽

Oxygen Flow Rate ◽

Oxide Thin Film ◽

Oxide Thin Films ◽

Sensing Applications

Metal oxide thin film materials, including SnO2, TiO2, WO3, MoO3, ZnO, have been widely studied for gas sensing applications. However, new gas-sensing materials with distinct and diverse characteristics for new sensing applications such as electronic nose are still being explored. Presently, gas sensing properties of other metal oxides have not yet been extensively explored. Chromium oxide is an interesting metal oxide for gas sensor because of its temperature stability and moderate electrical conductivity. Nevertheless, there have been very few studies on gas sensing behaviors of this material. In this work, chromium oxide thin films were systematically studied by reactive sputtering with varying sputtering parameter including oxygen flow rate. Structural characterization by means of scanning electron microscopy and X-ray diffraction reveals that the films have sub-micometer grain-size with Rhombohedral phase of Cr2O3. Gas-sensing performances of sputtered chromium oxide thin film have been characterized toward ethanol and acetylene sensing. It was found that chromium oxide thin films exhibit p-type conductivity with increased resistance when exposed to ethanol and acetylene, which are reducing gases. In addition, sensitivity to both acetylene and ethanol tend to improve as oxygen flow rate increases. Furthermore, the chromium oxide thin films exhibit high sensitivity at moderate temperature of 250-300 °C with minimum operating temperature of 200 °C.

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