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.

Preparation of transparent conducting ZnO:Al films on glass substrates by ultrasonic spray technique

Transparent conductive Al doped ZnO thin films were deposited by ultrasonic spray technique.Conditions of preparation have been optimized to get good quality.A set of aluminum（Al） doped ZnO（between 0 and 5 wt%） thin films were grown on glass substrate at 350℃.Nanocrystalline films with a hexagonal wurtzite structure show a strong（002） preferred orientation.The maximum value of grain size G = 32.05 nm is attained of Al doped ZnO film with 3 wt%.All the films have low absorbance in the visible region,thus the films are transparent in the visible region;the band gap energy increased from 3.10 to 3.26 eV when Al concentration increased from 0 to 3 wt%.The electrical conductivity of the films increased from 7.5 to 15.2（Ω·cm）^（-1）.So the best results are achieved in Al doped ZnO film with 3 wt%.

Correlation between electrical conductivity–optical band gap energy and precursor molarities ultrasonic spray deposition of ZnO thin films

ZnO thin films were deposited using the simple, flexible and cost-effective spray ultrasonic technique at different precursor molarities values. The films were deposited on a glass substrate at 350℃. This paper is to present a new approach to the description of correlation between electrical conductivity and optical gap energy with precursor molarity of ZnO thin films. The ZnO films exhibit higher electrical n-type semiconductors, whose band gap energy increased from 3.08 to 3.37 eV with an increasing of precursor molarity of 0.05 to 0.1 M. The maximum value of electrical conductivity of the films is 7.96 （S2.cm）-1 obtained in the ZnO thin film for precursor molarity 0.125 M. The correlation between the electrical and the optical properties with the precursor molarity suggests that the electrical conductivity of the films is predominantly influenced by the band gap energy and the precursor molarity. The measurement of the electrical conductivity of the films with correlation is equal to the experimental with the error is about 1% in the higher conductivity.

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.

Scalable fabrication of NiCo_(2)O_(4)/reduced graphene oxide composites by ultrasonic spray as binder-free electrodes for supercapacitors with ultralong lifetime

Durable and cost-effective electrode materials are essential for practical application of supercapacitors.Herein,large area NiCo_(2)O_(4)/reduced graphene oxide(NiCo_(2)O_(4)/rGO)composites with hierarchical structure were fabricated by a facile one-step ultrasonic spray on Ni foam and directly used as the binder-free electrodes for supercapacitors in aqueous KOH electrolyte.Owing to high electrical conductivity of rGO,hierarchical and layered structure of the electrode,as well as tight adhesion of active materials on the current collector,the as-obtained hybrid electrodes show a high specific capacitance of 871 F g^(-1)at current density of 1 A g^(-1),good rate performance and remarkable cycling stability with a capacitance retention of 134%after 30000 cycles.Besides,the assembled NiCo_(2)O_(4)/rGO//AC asymmetric supercapacitor(ASC)displays the maximum energy density of 29.3 Wh kg^(-1)at a power density of 790.8 W kg^(-1).Significantly,an ultralong cycling life of 102%capacitance retention is achieved for the ASC device after 30,000 charge/discharge cycles at 20 A g^(-1).The scalable fabrication route and excellent electrochemical performance of the NiCo_(2)O_(4)/rGO composites open the door for making novel hybrid electrodes of advanced supercapacitors.

Effect of SnCl2 and SnCl4 precursors on SnSx thin films prepared by ultrasonic spray pyrolysis

Thin films of SnSx,semiconductors,have been successfully synthesized by ultrasonic spray pyrolysis technique,using two precursors namely：tin（II）chloride and tin（IV）chloride,respectively.The solutions were prepared by the dilution of different Sn molarities of the two precursors separately.The precursor molarities were varied from 0.04 to 0.07 mol/L,whereas that of S was fixed at 0.1 mol/L.The present work focuses on the effect of the different precursor’s molarities on the nature and the properties of the prepared thin films in order to optimize the growth conditions.X-ray diffraction analysis reveals that the precursor’s molarities alter the grain size of the prepared films,which varied from 8 to 14 nm and from 12 to 16 nm,according to the used precursor.The films analysis by SEM,shows that the SnS2 films are more dense and smooth than the SnS films.The composition of the elements is analysed with an EDX spectrometer,and the obtained result for M（sn）=0：07 mol/L indicates that the atomic ratio of Sn to S is 51.57：48：43 and 36：64 for films synthesized from the first and second precursors respectively.Electrical measurements show that the conductivity behavior depends on the used precursors and their molarities.

Solution flow rate influence on ZnS thin films properties grown by ultrasonic spray for optoelectronic application

The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 nm.SEM analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.

Correlation between the structural, morphological, optical, and electrical properties of In_2O_3 thin films obtained by an ultrasonic spray CVD process

Indium oxide （In2O3） thin films are successfully times by an ultrasonic spray technique using Indium chloride deposited on glass substrate at different deposition as the precursor solution; the physical properties of these films are characterized by XRD, SEM, and UV-visible. XRD analysis showed that the films are polycrys- talline in nature having a cubic crystal structure and symmetry space group Ia3 with a preferred grain orientation along the （222） plane when the deposition time changes from 4 to 10 min, but when the deposition time equals 13 min we found that the majority of grains preferred the （400） plane. The surface morphology of the In2O3 thin films revealed that the shape of grains changes with the change of the preferential growth orientation. The trans- mittance improvement of In2O3 films was closely related to the good crystalline quality of the films. The optical gap energy is found to increase from 3.46 to 3.79 eV with the increasing of deposition time from 4 to 13 min. The film thickness was varied between 395 and 725 nm. The film grown at 13 min is found to exhibit low resistivity （10-2 Ω.cm）, and relatively high transmittance （- 93%）.

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.

AgNi15 composite particles prepared by ultrasonic arc spray atomization method

Ultrasonic arc spray atomization (UASA) method was used to prepare high-melting-point, immiscible AgNi15 (mass fraction, %) composite particles. Sieving was used to determine the size distribution of the AgNi15 particles. The morphology, rapidly solidified structure and metastable solution expansion of the AgNi15 particles were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), respectively. The results show that the AgNi15 composite particles are spherical and well-dispersed, and the mass fractions of the particles with diameters <74μm and <55 μm are 99.5% and 98%, respectively. The rapidly solidified structure of the AgNi15 particles consists of spherical nickel-richβ(Ni)-phase particles dispersed throughout a silver-richα(Ag)-phase matrix andα(Ag)-phase nanoparticles dispersed throughout largerβ(Ni)-phase particles. The silver and nickel in the AgNi15 particles form a reciprocally extended metastable solution, and the solid solubility of nickel in the silver matrix at room temperature is in the range of 0.16%?0.36% (mole fraction).

Bulk heterojunction thin film formation by single and dual feed ultrasonic spray method for application in organic solar cells

We here present a way of preparing the polymer： fullerene BHJ using dual feed method which can lead to formation of pure phases. In this report, we present results of our initial experiments in this direction.The effect of process parameters on the thickness and surface roughness of the active layer has been discussed.The structural and optical properties have been studied using the optical microscope, UV–visible spectroscopy and photoluminescence spectroscopy. Significant PL quenching indicates efficient charge separation in the BHJ formed using this technique. We have also compared the BHJ thin films prepared with this dual feed ultrasonic technique with the single feed spray method. The BHJ formed using this technique has been used as an active layer in OSC.

The effect of the film thickness and doping content of SnO2:F thin films prepared by the ultrasonic spray method

This paper reports on the effects of film thickness and doping content on the optical and electrical properties of fluorine-doped tin oxide. Tin （Ⅱ） chloride dehydrate, ammonium fluoride dehydrate, ethanol and HC1 were used as the starting materials, dopant source, solvent and stabilizer, respectively. The doped films were deposited on a glass substrate at different concentrations varying between 0 and 5 wt% using an ultrasonic spray technique. The SnO2：F thin films were deposited at a 350 ℃ pending time （5, 15, 60 and 90 s）. The average transmission was about 80%, and the films were thus transparent in the visible region. The optical energy gap of the doped films with 2.5 wt% F was found to increase from 3.47 to 3.89 eV with increasing film thickness, and increased after doping at 5 wt%. The decrease in the Urbach energy of the SnO2：F thin films indicated a decrease in the defects. The increase in the electrical conductivity of the films reached maximum values of 278.9 and 281.9 （Ω.cm）-1 for 2.5 and 5 wt% F, respectively, indicating that the films exhibited an n-type semiconducting nature. A systematic study on the influence of film thickness and doping content on the properties of SnO2：F thin films deposited by ultrasonic spray was reported.

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%）.

Salt-assisted Synthesis of Hollow Bi_2WO_6 Microspheres with Superior Photocatalytic Activity for NO Removal

Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.

Structural, optical and electrical properties of Sn_xS_y thin films grown by spray ultrasonic

Tin sulfide（Snx Sy/ thin films were prepared by a spray ultrasonic technique on glass substrate at 300℃.The influence of deposition time tD2, 4, 6, 8 and 10 min on different properties of thin films, such as（XRD）,photoluminescence（PL） and（UV） spectroscopy visible spectrum and four-point were investigated. X-ray diffraction showed that thin films crystallized in SnS2, SnS, and Sn2S3 phases, but the most prominent one is SnS_2. The results of the（UV） spectroscopy visible spectrum show that the film which was deposited at 4 min has a large transmittance of 60% in the visible region. The photoluminescence spectra exhibited the luminescent peaks in the visible region, which shows its potential application in photovoltaic devices. The electrical resistivity（ρ） values of SnxSy films have changed from 8.1×1064to 1.62Ω·cm with deposition time.

Properties of n-type SnO_2 semiconductor prepared by spray ultrasonic technique for photovoltaic applications

Transparent conducting n-type SnO2 semiconductor films were fabricated by employing an inexpensive, simplified spray ultrasonic technique using an ultrasonic generator at deferent substrate temperatures （300, 350, 400, 450 and 500 ℃）. The structural studies reveal that the SnO2 films are polycrystalline at 350,400, 450, 500 ℃ with preferential orientation along the （200） and （101） planes, and amorphous at 300 ℃. The crystallite size of the films was found to be in the range of 20.9-72.2 nm. The optical transmittance in the visible range and the optical band gap are 80% and 3.9 eV respectively. The films thicknesses were varied between 466 and 1840 nm. The resistivity was found between 1.6 and 4 × 10^-2 Ω.cm. This simplified ultrasonic spray technique may be considered as a promising alternative to a conventional spray for the massive production of economic SnO2 films for solar cells, sensors and opto-electronic applications.

Influence of growth time on crystalline structure,conductivity and optical properties of ZnO thin films

This paper examines the growth of ZnO thin films on glass substrate at 350 ℃ using an ultrasonic spray technique. We have investigated the influence of growth time ranging from 1 to 4 min on structural, optical and electrical properties of ZnO thin films. The as-grown films exhibit a hexagonal structure wurtzite and are （002） oriented. The maximum value of grain size G = 63.99 nm is attained for ZnO films grown at 2 min. The average transmittance is about 80%, thus the films are transparent in the visible region. The optical gap energy is found to increase from 3.26 to 3.37 eV with growth time increased from 1 to 2 min. The minimum value of electrical resistivity of the films is 0.13 Ω.cm obtained at 2 min. A systematic study on the influence of growth time on the properties of ZnO thin films deposited by ultrasonic spray at 350 ℃ has been reported.