Papers by Keyword: Aerosol Deposition

Abstract: Zinc oxide (ZnO) is a low toxicity and environmentally friendly material, and it is applied on devices, sensors or actuators for trending towards green-life. A porous ZnO film deposited by a rapid process of aerosol deposition (AD) was employed as the gas-sensitive material in a CO gas sensor for reducing the manufacturing cost and time, further extending the AD application. A relative resistance change (R / R) of the ZnO gas sensor was used for CO gas measurement. The sensitivity of the fabricated ZnO gas sensors had a more outstanding performance about 49%, compared to the literature data reported by Joshi.

Abstract: Fabrication of nanoporous titanium dioxide (TiO₂) films was examined for their application as the negative electrode of a dye-sensitized solar cell (DSC). Composite films were fabricated by aerosol deposition using a powder mixture of TiO₂ and aluminum nitride (AlN). A nanoporous structure was subsequently formed in the film by dissolving the AIN in hot water. Remarkable differences in the surface morphology of the films were observed for different mixing ratios of TiO₂ and AlN particles. AlN particles remained in the films, but not at the surface. The power conversion efficiency of a DSC was improved by incorporating these nanoporous TiO₂ films.

Abstract: Films of titanium dioxide (TiO₂) were deposited by aerosol deposition at room temperature. Anatase TiO₂ powders were used. The crystal structure of these films was a mixture of the anatase and brookite TiO₂ phases, while the rutile TiO₂ phase was observed at high carrier gas flow rates. The TiO₂ film thickness increased in proportion with the scan time and the carrier gas flow rate. Film thickness was constant at constant total deposition times. Flake-like and mesh-like surface morphologies were observed on the films. The direct-current resistivity was estimated from the dielectric constant and the loss tangent; it was found to be much smaller than that of bulk TiO₂. We speculate that this low resistivity is due to reduction of TiO₂ particles during room-temperature impact consolidation in a N₂ atmosphere.

Abstract: This work present a low resistance dye-sensitized solar cell (DSSC) based on metal substrates. Different kinds of metal meshes are used to fabricate nanocrystalline TiO2 electrode and counter-electrode. The nanoporous TiO2 thin films were fabricated via an aerosol deposition method. The TiO2 colloid was produced by dissolving P25 powder in deionized (DI) water and atomized using an ultrasonic nebulizer. The flexible electrodes can be sintered under 450–550 °C and exhibit high-temperature sinterability. The tuning of TiO2 film thickness coated on metal mesh towards optimization of solar energy conversion efficiency had been investigated. Experimental results show that the excellent electric conductivities improve the fill factor and conversion efficiency for the large-size DSSCs due to the reduced internal resistance of the cell. These flexible metal substrates are a promising approach especially from the viewpoint of large-scale, cost effective industrial manufacturing of solar cells.

Abstract: Full-dense bulk Pb(Zr,Ti)O3 (PZT) ceramics with various grain sizes were prepared by aerosol deposition (AD) employing various firing temperature from 800 to 1200°C. It was confirmed that the Hall-Petch relationship is obeyed in AD-processed PZT ceramics over the almost whole grain size range, which is indicating that only grain size could be the determining factor of hardness in AD since density is almost constant against the grain size. As compared with conventional sintering technique, AD-processed PZT ceramics exhibited higher hardness and higher or at least equivalent electrical properties over the whole grain size range investigated, which is indicating that the piezoelectric ceramics with improved mechanical properties can be realized by AD without any sacrifice in electrical properties.

Abstract: To retain the driving properties of metal-based micro optical scanner derived by aerosol deposition (AD) technique, CO2 laser irradiation was used to anneal the PZT films deposited onto the stainless-steel substrate. Stainless-steel mirror and frame of the scanner with the film annealed by laser irradiation maintained their metallic luster. The scanner with the film annealed by laser irradiation at 600 °C for 1 min has a scanning angle over 30 degree that is comparable with the scanning angle of a similar scanner annealed by electric furnace at 600 °C for 10 min.

Abstract: (Ba0.6,Sr0.4)TiO3 thick films have been fabricated on various substrates and their physical and electrical properties were analyzed. The effect of primary powder condition on the quality of the BST fabricated films using aerosol deposition technique has been investigated keeping in mind results shown in the literature for BST films fabricated with classical deposition techniques. Presence of carbonates and TiO2 has been demonstrated by XPS analysis and the leakage current behavior has linked to the presence of TiO2 at the grain boundaries. The films showed good insulating properties, with small leakage densities being on the order of 10-6 A/cm2 for an applied electric field of 150 kV/cm.

Abstract: This research investigated the water purification performance of thin film with anatase phase TiO2 powder having good photocatalytic property using an innovative aerosol deposition method at the normal room temperature. Fresh raw powder was dehydrated for good dispersion of TiO2 powder. To suppress the formation of second particle, the powder was dispersed for 90 minutes in alcohol bath with ultrasonic treatment and then desiccated. The average grain size of particle was identified to be 1µm in TiO2 thin film deposited on stainless steel mesh by scanning electron microscopy (SEM). The anatase phase of TiO2 thin film was investigated by X-ray diffraction (XRD). The anatase phase of fresh raw powder was favorably maintained after aerosol deposition treatment.