Characteristics of SnO_(2):F Thin Films Deposited by Ultrasonic Spray Pyrolysis:Effect of Water Content in Solution and Substrate Temperature

Fluorine doped tin oxide, SnO2:F, thin films were deposited by ultrasonic chemical spray starting from tin chloride and hydrofluoric acid. The physical characteristics of the films as a function of both water content in the starting solution and substrate temperature were studied. The film structure was polycrystalline in all cases, showing that the intensity of (200) peak increased with the water content in the starting solution. The electrical resistivity decreased with the water content, reaching a minimum value, in the order of 8 × 10-4 Ωcm, for films deposited at 450℃ from a starting solution with a water content of 10 ml per 100 ml of solution;further increase in water content increased the corresponding resistivity. Optical transmittances of SnO2:F films were high, in the order of 75%, and the band gap values oscillated around 3.9 eV. SEM analysis showed uniform surface morphologies with different geometries depending on the deposition conditions. Composition analysis showed a stoichiometric compound with a [Sn/O] ratio around 1:2 in all samples. The presence of F into the SnO2 lattice was detected, within 2 at % respect to Sn.

Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

Indium doped zinc oxide （ZnO：In） thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO：In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10^-3 Ω. cm and particle grains. The doublelayers structure is designed to fabricate the ZnO：In thin film with low resistivity （2.58 × 10^-3 Ω. cm） and good surface morphology. It is found that the surface morphology of the double-layer ZnO：In film strongly depends on the substratelayer, and the second-layer plays a large part in the resistivity of the doublewlayer ZnO：In thin film. Both total and direct transmittances of the double-layer ZnO：In film are above 80% in the visible light region. Single junction a-Si：H solar cell based on the double-layer ZnO：In as front electrode is also investigated.

Transparent conductive stannic oxide coatings employing an ultrasonic spray pyrolysis technique:The relevance of the molarity content in the aerosol solution for improvement the electrical properties

Highly transparent conductive stoichiometric nanocrystalline stannic oxide coatings were deposited onto Corning®EAGLE XG®slim glass substrates.Including each coating,it was deposited for various concentrations in the aerosol solution with the substrate temperature maintained at 623.15 K by an ultrasonic spray pyrolysis(USP)technique.Nitrogen was em-ployed both as the solution carrier in addition to aerosol directing gas,maintaining its flow rates at 3500.0 and 500.0 mL/min,respectively.The coatings were polycrystalline,with preferential growth along the stannic oxide(112)plane,irrespective of the molarity content in the spray solution.The coating prepared at 0.2 M,a concentration in the aerosol solution,showed an average transmission of 60%in the visible light region spectrum with a maximum conductivity of 24.86 S/cm.The coatings deposited exhibited in the general photoluminescence spectrum emission colors of green,greenish white,and bluish white calculated on the intensities of the excitonic and oxygen vacancy defect level emissions.

Characterization of CeO_(2)microspheres fabricated by an ultrasonic spray pyrolysis method

CeO_(2) is one of the main catalysts for solid oxide fuel cell(SOFC).It is critical to find a green and costeffective fabrication method for CeO_(2) at scale.In this study,the CeO_(2) microspheres were prepared by one-step ultrasonic spray pyrolysis of cerium chloride solution at700℃.Scanning electron microscopy(SEM)and transmission electron microscopy(TEM)study demonstrate that the prepared CeO_(2) microspheres exhibit a particle size of0.01-1.08μm with a mean particle size of 0.23μm,and more than 94%of the particles have a diameter less than0.5μm.But the presence of residual Cl in the fabricated CeO_(2) microspheres blocks the active sites and leads to the significant degradation of SOFC performance.The formation mechanism and distribution of residual Cl in the fabricated CeO_(2) microspheres were systemic ally studied.The water washing method was shown to effectively reduce the residual Cl in the CeO_(2) microspheres.Overall,this work provides a clean manufacturing process for the preparation of SOFC electrode/electrolyte materials.

Ultrasonic spray pyrolysis deposition of SnSe and SnSe_2 using a single spray solution

Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis（USP） technique.To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution.The use of a single spray solution for obtaining both a p-type material,SnSe,and an n-type material,SnSe2,simplifies the deposition technique.The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV.The Hall measurements were used to determine the resistivity of the thin films.The SnSe2 thin films show a resistivity of 36.73 Ωcm and n-type conductivity while the SnSe thin films show a resistivity of 180 Ωcm and p-type conductivity.

Synthesis of indium tin oxide nano-polycrystalline powders by ultrasonic spray pyrolysis

Indium tin oxide(ITO) nano-polycrystalline powders were prepared by ultrasonic spray pyrolysis(USP) method using a precursor solution of indium and tin chlorides in a simple one-step process without any post-heat treatment,additives and other complex operations.The morphology and crystal structure of ITO powders were studied by thermogravimetric and differential thermal analysis(TG-DTA),X-ray diffraction(XRD),energy-dispersive spectrometer(EDS),scanning electron microscopy(SEM),laser particle size analyzer(LPSA),transmission electron microscope(TEM),high-resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED),respectively.The results indicate that pure cubic ITO solid solution could be obtained at and above the pyrolysis temperature of 600℃.Through adjusting the size of atomized precursor droplets,the particles with regular spherical shape and smooth surface are also obtained.The spherical particles have a narrow size distribution with a dominant diameter size in the range of 0.52-1.28 μm,and the average value is 1.01 μm.The clear lattice fringes in HRTEM image confirm a polycrystalline structure of ITO particles with the growth direction along(222) direction.

Spray pyrolysis synthesis of nickel-rich layered cathodes LiNi_(1-2x)Co_xMn_xO_2(x = 0.075, 0.05, 0.025) for lithium-ion batteries

In this study we report a series of nickel-rich layered cathodes LiNi1-2xCoxMnxO2（x = 0.075, 0.05,0.025） prepared from chlorides solution via ultrasonic spray pyrolysis. SEM images illustrate that the samples are submicron-sized particles and the particle sizes increase with the increase of Ni content.LiNi0.85Co0.075Mn0.075O2 delivers a discharge capacity of 174.9 mAh g-1 with holding 93% reversible capacity at 1 C after 80 cycles, and can maintain a discharge capacity of 175.3 mAh g-1 at 5 C rate. With increasing Ni content, the initial specific capacity increases while the cycling and rate performance degrades in some extent. These satisfying results demonstrate that spray pyrolysis is a powerful and efficient synthesis technology for producing Ni-rich layered cathode（Ni content 〉 80%）.

Photoluminescence enhancement of red-emitting GdVO_4:Eu and YVO_4:Eu phosphors by adding zinc

We synthesized the rare-earth activated Ro.94_xEuo.06ZnxVO4 （R： Gd and Y; 0〈_x〈_0.08） phosphors with a spherical mor- phology and a smooth surface by the ultrasonic spray pyrolysis. The annealed Ro.94_xEuo.06ZnxVO4 crystallized in the tetragonal zircon type structure, belonging to the space group of I41/amd. The incorporation of a small amount of Zn to Ro.94Euo.06VO4 improved the emission characteristics. The emission intensities of the Gdo.88EUo.06Zno.06VO4 and Yo.9Euo.06Zno.04VO4 phosphors at 619 nm were 72% and 2 1% stronger than those of the Gdo,94Euo.06VO4 and Yo.94Euo.06VO4 phosphors, respectively. We demonstrated that the addi- tion of Zn to Ro.94Euo.06VO4 was quite effective for improving the photoluminescent properties.