Aerosol-assisted CVD Research Articles

Effect of Solvent on the Structural and Morphological Properties of α-Fe2O3 Deposited at Different Temperatures Using Aerosol-assisted CVD in an In-house Built Setup

Effect of Solvent on the Structural and Morphological Properties of α-Fe2O3 Deposited at Different Temperatures Using Aerosol-assisted CVD in an In-house Built Setup

Aerosol-Assisted CVD As The Economically Method to Deposit The Solar Cell, An Overview of The Electrical and Structural Properties

Aerosol-Assisted CVD As The Economically Method to Deposit The Solar Cell, An Overview of The Electrical and Structural Properties

Photoluminescence analysis of CsPb2Cl5 and CsPbCl3 perovskite films doped with Yb3+ deposited by aerosol-assisted CVD

Low-dimensional all-inorganic metal halide perovskites (MHPs) have attracted attention due to their promising advantages as semiconductor materials for optoelectronic applications. However, obtaining a low-dimensional MHPs pure phase has been difficult due to its high ionic nature. Here, the one-step in-situ deposition of CsPb2Cl5 films by Aerosol Assisted Chemical Vapor Deposition (AACVD) is reported for the first time. An analysis of the effects of precursor concentrations, using ethanol (EtOH) as antisolvent, and Yb3+ doping on the resulting three-dimensional and/or two-dimensional perovskite phase films is presented. It was found that a lead rich precursor (PbCl2:CsCl = 2:1) was necessary to promote the formation of the CsPb2Cl5 phase, in addition, the use of EtOH and doping with hetero-valent Yb3+ ions was required to attain this phase successfully. The excitation and emission photoluminescence spectra analysis for these films is focused on the three principal emissions: i) a narrow emission peak around 418 nm from the CsPbCl3 phase, ii) a dual broad emission around 550 nm from the CsPb2Cl5 phase, and iii) an emission at 984 nm associated with the Yb3+ ions introduced as dopants in the MHPs lattice. A possible mechanism is proposed for the observed energy transfer from the CsPb2Cl5 matrix to the ytterbium ions and for the interactions between Yb3+ and the excitonic emissions.

Enhanced Hall Mobility and d0 Ferromagnetism in Li-Doped ZnO Thin Films Prepared by Aerosol-Assisted CVD

Enhanced Hall Mobility and d0 Ferromagnetism in Li-Doped ZnO Thin Films Prepared by Aerosol-Assisted CVD

AACVD system and protocol to fabricate CuO and Co3O4 nanostructured coatings for application as selective absorbent materials

In the present work, an aerosol-assisted CVD (AACVD) system is described, together with a representative example of the synthesis of nanostructured coatings, which is an attractive alternative to being implemented at the industrial level. The semi-automated AACVD system synthesizes thin films or coatings of nanostructured materials, mainly metal oxides, and noble metals. Its main components, as well as its operation, are presented here. This simple AACVD method makes it possible to produce the coatings at relatively low temperatures and in a single step. Finally, the synthesis of CuO and Co3O4 nanostructured coatings deposited on stainless steel substrates is reported, which are excellent candidates for use as selective absorbent materials. The CuO and Co3O4 coatings present high quality and purity; no further thermal treatments are required to obtain the pure and crystalline phases. The main highlights of the proposed method are as follows: a)An AACVD System for depositing thin films and coatings designed and entirely fabricated at the Centro de Investigación en Materiales Avanzados, S.C.b)A low temperature (350 °C) synthesis protocol to obtain CuO and Co3O4 nanostructured coatings on stainless steel substrates.c)The CuO and Co3O4 coatings presented the optimum characteristics to be considered selective absorbent materials.

Aerosol-assisted CVD of nickel oxide on silicon for hole selective contact layers

Aerosol-assisted CVD of nickel oxide on silicon for hole selective contact layers

AACVD processed binary amorphous NiVOx coatings on Cu substrates: Surface characterization and corrosion resistant performance in saline medium

Cu corrosion is a major issue affecting the structural integrity and efficient performance of Cu components in several applications. In recent years, the utilization of metal oxide thin films on copper components is fascinated cumulative consideration particularly in the field of energy and electronic related materials like micro-electromechanical, energy storage and memory device components. Herein, we report the use of a rapid and reproducible approach of aerosol-assisted (AA) CVD for depositing bimetallic nickel-vanadium oxide (NiVOx) thin films directly on Cu substrates. NiVOx coatings were produced by increasing the deposition period from 1 to 3 h at a fixed temperature of 480 °C and were structurally characterized through XRD analysis, XPS, SEM/EDS, and AFM. Detailed characterization was performed for the as-prepared amorphous NiVOx binary films having a compact and dense microstructure at an elemental stoichiometry of Ni/V in 1:1 ratio. Corrosion analyses, including electrochemical frequency modulation, Tafel plot analysis, and dynamic electrochemical impedance spectroscopy, were performed to assess the corrosion resistance performance of binary films on Cu substrates in saline medium. Moreover, scanning electrochemical microscopy was accomplished to estimate the electrochemical stability of the as-processed binary films during the 24-h immersion period in NaCl.

Cu2O Thin Films: The Role of Humidity in Tuning the Texture and Electrical Properties of Cu2O Thin Films Deposited via Aerosol‐Assisted CVD (Adv. Mater. Interfaces 3/2019)

Cu₂O Thin Films: The Role of Humidity in Tuning the Texture and Electrical Properties of Cu₂O Thin Films Deposited via Aerosol‐Assisted CVD (Adv. Mater. Interfaces 3/2019)

Fabrication of robust superhydrophobic surfaces via aerosol-assisted CVD and thermo-triggered healing of superhydrophobicity by recovery of roughness structures

Robust superhydrophobic surfaces were fabricated via aerosol-assisted CVD of epoxy resins and PDMS polymer films. The as-obtained surfaces showed thermo-triggered healing of the superhydrophobicity by recovery of roughness structures.

Photocatalytic and electrically conductive transparent Cl-doped ZnO thin films via aerosol-assisted chemical vapour deposition

Cl-doped ZnO films, grown via aerosol-assisted CVD, can function as both TCOs and photocatalysts.

Aerosol-assisted CVD of thioether-functionalised indium aminoalkoxides

Thioether-functionalised indium aminoalcoholates have been used as single-source precursors in aerosol-assisted CVD processes. The obtained In2O3−xSx oxysulphide deposits show either a single indium sulphide phase for deposits with high sulphide content [>75% (S/(S + O)) for the t-butyl derivatives] or pronounced phase separation in indium oxide and indium sulphide for lower sulphide content [<62% (S/(S + O)) for the n-butyl derivatives]. In addition to thin films, polycrystalline 1D structures are obtained at slightly modified synthesis conditions. The materials are analysed by EDX, XRD, XPS, SEM, and TEM.Graphical abstract

Aerosol-assisted CVD of SnO from stannous alkoxide precursors.

The stannous alkoxides [Sn(OR)2] [R = i-Pr, t-Bu, C(Et)Me2, CHPh2, CPh3] have been synthesised by reaction of Sn(NR'2)2 with two equivalents of HOR [R' = Me, R = i-Pr; R' = SiMe3, R = t-Bu, C(Et)Me2, CHPh2, CPh3]. Single crystal X-ray diffraction analysis of the bis(diphenylmethoxide) (4) and bis(triphenylmethoxide) (5) species have shown them to comprise three-coordinate Sn(ii) centres through dimerisation in the solid state with the alkoxide units adopting transoid and cisoid configurations across the {Sn2O2} cores respectively. Thermogravimetric analysis indicates clean decomposition and some evidence of volatility at temperatures >200 °C for all three aliphatic alkoxides, whereas both the diphenyl- and triphenylmethoxide compounds provide higher decomposition temperatures and, for the triphenylmethoxide derivative, a residual mass consistent with the formation of a carbon-containing residue. The previously reported iso-propoxide (1) and tert-butoxide (2) derivatives have been utilised in toluene solution to deposit SnO thin films by aerosol-assisted chemical vapour deposition (AACVD) on glass at temperatures between 300 and 450 °C. While SnO is deposited under hot wall conditions as the only identifiable phase by p-XRD and Raman spectroscopy for both precursors, morphological analysis by SEM reveals inferior substrate coverage in comparison to previously reported ureide-based precursor systems.

Indium Tin Oxide – Silicon Nanocrystal Nanocomposite Grown by Aerosol-Assisted Chemical Vapour Deposition

Nanocomposite films were grown by aerosol-assisted chemical vapour deposition in a single deposition process using a mixture of indium tin neodecanoate and ligand stabilized silicon nanocrystals dispersed in a solvent. Samples were analysed by HRTEM and silicon nanocrystals with a density of 1.2 x 1012 cm-2 were observed. From the reconstructed 3D tomogram, the averaged distance between the nearest nanoparticles is 8.3nm and the 3D density of nanoparticles is 1.6 x 1018 cm-3. These data show the versatility of aerosol-assisted CVD in achieving a high density of nanocrystals within a polycrystalline host-matrix, meeting the density and size distribution requirements for particle inclusion in active nanocomposites for photovoltaic applications.

Localized aerosol-assisted CVD of nanomaterials for the fabrication of monolithic gas sensor microarrays

The self-heating capability of MEMS-based devices is used to grow locally into the sensing active area of monolithic gas sensor microarrays differently-functionalized materials via aerosol-assisted CVD. Results derived from SEM, TEM, XRD and Raman demonstrate the integration of non-functionalized (WO3−x) and functionalized nanostructures with gold (WO3-x/Au) or platinum (WO3-x/Pt) NPs into the array. Tests of these microarrays toward various concentrations of reducing gases show stable and reproducible responses, with the highest responses (R) for WO3−x to carbon monoxide (e.g. R=4.3–80ppm), for WO3−x/Au to ethanol (e.g. R=7–80ppm) and for WO3−x/Pt to hydrogen (e.g. R=3.6–80ppm). Principal component analysis of the sensor response replicates to each gas and concentration suggest that the differences in the sensing properties of each element of the array provide the complementary information to discriminate H2 and EtOH from CO.

Molecular routes to Cu2ZnSnS4: A comparison of approaches to bulk and thin-film materials

A range of xanthates (R′3P)2CuS2COR [R′ = Ph, R = Et (1), i-Pr (2), t-Bu (3), t-Amyl (4); R′ = PhO, R = Et (5), R′ = n-Bu, R = Et (6), Bun (7)], M(S2COR)2 [M = Sn R = Et (8); Zn, R = Et (10), i-Pr (11), n-Pr (12), n-Bu (13), n-Hex (14)], Sn(S2COEt)4 (9), Zn(S2COEt)2.TMEDA (15) have been synthesised and their thermal decomposition profiles delineated by TGA. A parallel range of dithiocarbamates (R′3P)2CuS2CN(Me)R [R′ = Ph, R = Bun (16), Bz (17)], M[S2CN(Me)R]2 [M = Sn, R = Bun (18), Bz (19); M = Zn, R = Bun (21), Bz (22)] has been similarly assessed. Although precursor combinations have been found from these systems that generate Cu2ZnSnS4 (CZTS) from either a bulk decomposition (1, 8, 10 at 400 °C/Ar; Cu2Zn1.02Sn0.74S4.6), from a doctor-bladed film (7, 8, 13 at 400 °C/Ar; Cu2Zn1.2Sn1.0S3.6), and as nanoparticles (7, 8, 13 in octadecane/oleic acid, 150 °C; Cu2Zn1.0Sn0.7S2.6), attempts to deposit CZTS by aerosol-assisted CVD has proved more challenging and only successful from the dithiocarbamates 16, 18, 21 (350 °C; Cu2Zn0.9Sn0.7). As part of this work the crystal structures of 2–5, 8, 16, and the dithiocarbamate decomposition product {Sn[S2CN(Me)Bun)]2S}2 (20) have been determined.

Characterization and hydrogen storage in multi-walled carbon nanotubes grown by aerosol-assisted CVD method

The characterization and hydrogen storage capacity of multi-walled carbon nanotubes (MWCNTs) have been studied in the present work. MWCNTs with high purity and bulk yield were achieved from a mixture of camphor/alcohol on a Ni/zeolite support by aerosol-assisted chemical vapor deposition (AACVD). The morphology, surface quality and structure of MWCNTs were characterized by transmission electron microscopy (TEM). Crystallinity and defects of the MWCNTs were studied by Raman spectroscopy and thermo gravimetric analysis (TGA). Hydrogen storage properties of MWCNTs were investigated using a quartz crystal microbalance (QCM). Values between 1.2 and 2.0 wt.% of adsorbed H2 were reached depending on the exposure pressure. The results also showed that the remaining zeolite present in the as-prepared MWCNT powder adsorbs hydrogen, allowing better adsorption performance of the CNT12 and CNT13 samples. The hydrogen adsorption behavior of CNTs is significantly affected by their structural and morphological characteristics.

Gas Sensing Properties of Metal-decorated Tungsten Oxide Nanowires Directly Grown onto Flexible Polymeric Hotplates

Aerosol assisted CVD (AACVD) is a self-catalyzed method that allows for growing single crystalline metal oxide nanowires at moderate temperatures (i.e. up to 380°C). This is employed here to grow either Pt or Au-decorated tungsten oxide nanowires directly on flexible polymeric hotplates. E-SEM, EDX and XRD analysis have been used to investigate the morphology and the composition of the nanostructures grown. The functionality of the devices has been demonstrated by testing their gas sensing properties to ethanol, hydrogen and nitrogen dioxide. These flexible sensors show excellent and fast responses, good baseline recovery and repeatability. Tested over a few months, they show also excellent stability. These sensors are good candidates for being integrated in flexible tags for air quality control.

Antimicrobial activity of copper and copper(i) oxide thin films deposited via aerosol-assisted CVD.

Hospital acquired infections are prevalent in many hospitals and contaminated touch surfaces are a route of transmission. To find a solution for this, copper and copper oxide thin films were deposited via aerosol assisted chemical vapour deposition using copper nitrate as the precursor and the films were characterised by a range of techniques including powder X-ray diffraction and scanning electron microscopy. The antimicrobial activity of the deposited copper and copper oxide films were investigated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). A 5-log10 reduction in the viable counts of E. coli was observed on the copper thin films after 30 minutes while a 2-log10 reduction was observed on copper oxide films after 1 hour. In the case of S. aureus both copper and copper oxide films exhibited 4-log10 reduction after 1 hour. The high antimicrobial efficacy of the Cu2O films, approaching that of the pure copper films, suggests that oxide formation on copper objects should not significantly impair their antimicrobial activity.

Influence of Deposition Time on Amorphous Carbon Thin Films Performance with Aerosol-Assisted Chemical Vapor Deposition

Pure amorphous Carbon (a-C) thin films had been deposited by Aerosol-Assisted CVD (AACVD) onto glass substrate in Argon atmosphere. The camphor oil was chosen as the carbon precursor to prepare the a-C thin films with the deposition time of 15 minutes, 30 minutes, 45 minutes, 60 minutes and 75 minutes. The electrical, optical and structural properties of the deposited a-C were discussed by using the current-voltage solar simulator system, UV-Vis-Nir spectrophotometer and Raman spectroscope respectively. For the electrical characterization, the samples showed the photoresponse performance when being illuminated under AM 1.5 illuminations: 100 mW/cm2, 25°C. Transmittance value for the a-C thin films was also considered high ~80% and the structural analysis by using Raman spectroscope exhibit two main peaks known as the D-peak and G-peak which is typical for the a-C.

Nitrogen Incorporation of Nanostructured Amorphous Carbon Thin Films by Aerosol-Assisted Chemical Vapor Deposition

Nanostructured pure a-C and nitrogen doped a-C: N thin films with small particle size of, ~50 nm were obtained by Aerosol-assisted CVD method from the natural precursor camphor oil. Five samples were prepared for the a-C and a-C: N respectively, with the deposition temperatures ranging from <TEX>$400^{\circ}C$</TEX> to <TEX>$600^{\circ}C$</TEX>. At high temperature, the AFM clarifies an even smoother image, due to the increase of the energetic carbon ion bombardment at the surface of the thin film. An ohmic contact was acquired from the current-voltage solar simulator characterization. The higher conductivity of a-C: N, of <TEX>${\sim}{\times}10^{-2}Scm^{-1}$</TEX> is due to the decrease in defects since the spin density gap decrease with the nitrogen addition. Pure a-C exhibit absorption coefficient, <TEX>${\alpha}$</TEX> of <TEX>$10^4cm^{-1}$</TEX>, whereas for a-C:N, <TEX>${\alpha}$</TEX> is of <TEX>$10^5cm^{-1}$</TEX>. The high <TEX>${\sigma}$</TEX> value of a-C:N is due to the presence of more graphitic component (<TEX>$sp^2$</TEX> carbon bonding) in the carbon films.