Aerosol‐Assisted CVD of SnO₂ Thin Films for Gas‐Sensor Applications

Abstract

In this article is a report of SnO2 deposition by aerosol‐assisted (AA)CVD from tin complexes, [Sn(18‐Cr‐6)Cl4] and [Sn(H2O)2Cl4](18‐Cr‐6). The structure and properties of the precursors, used to synthesize SnO2 layers by AACVD for the first time, are characterized with the help of X‐ray diffraction (XRD), infrared (IR), and thermogravimetric analysis (TGA). Each complex is deposited by AACVD at 250, 400, and 500 °C in a flow of N2. The resulting films are studied by XRD and atomic force microscopy (AFM). Gas‐sensing properties of the deposited layers are tested to 10 ppm NO2 in air. The maximum sensor response to the analyte is measured at 300 °C.

Chemical Vapour Deposition of Gas Sensitive Metal Oxides

“…This was attributed to the smaller grains produced via L-CVD which were considered to improve gas diffusion through grains [66,67]. Similar observations were also noticed for SnO 2 grown via AACVD, indicating that grains with smaller size elongated in one direction increase the sensor response [65]. The positive influence of small grain-like SnO 2 surfaces for sensing reductive gases as H 2 compared to compact films was also noticed, and this was attributed to the higher degree of reduction to Sn 2+ or Sn˝species in grain-like SnO 2 surfaces, likely at the outermost surface layer of the grains where oxygen vacancies can be stabilized [60].…”

Aerosol assisted chemical vapour deposition of gas sensitive SnO2 and Au-functionalised SnO2 nanorods via a non-catalysed vapour solid (VS) mechanism

“…These characteristics are highly enhanced compared to our previous sensors based on SnO 2 NPs synthesised via AACVD of tin complexes34; which showed a very slow and low resistance change to NO 2 and non-sensitivity towards H 2 or CO. A direct comparison of our results and those of the literature is relatively complex, as the performance of the sensor is not only linked to the material properties, but also in part to the characteristics of the transducers and test conditions (e.g., operating temperatures, flows, and gas concentrations). Despite this we believe that Table 1 can still be useful to evaluate the tendency of SnO 2 towards the analytes tested in this work.…”

“…There are very few reports on synthesis of tin oxide or tin oxide composites via AACVD, with most referring to the formation of thin films3334353637383940 rather than nanostructures. The precursors used for the AACVD of tin oxide include common precursors used in traditional CVD41, such as monobutyltin trichloride (C 4 H 9 SnCl 3 )3840, and tin(II) chloride dihydrate (SnCl 2 ·2H 2 O)3342, tin complexes [Sn(18-Cr-6)Cl 4 ]34 and [Sn(H 2 O) 2 Cl 4 ](18-Cr-6)34, or for the deposition of composite films bimetallic complexes such as C 29 H 40 FeO 2 Sn37, C 35 H 28 FeO 2 Sn37, or [ZnSn(dmae)(dmaeH) 2 (NO 3 )Cl 4 ]·2H 2 O39.…”

Solution based CVD of main group materials

“…258 The gas sensing properties of the resulting films were tested to 10 ppm NO 2 in air at operating temperatures of 200, 250 and 300 1C. 258 The gas sensing properties of the resulting films were tested to 10 ppm NO 2 in air at operating temperatures of 200, 250 and 300 1C.…”