Investigation on Sensing Performance of Highly Doped Sb/SnO2

Abstract

Tin dioxide (SnO2) is the most-used semiconductor for gas sensing applications. However, lack of selectivity and humidity influence limit its potential usage. Antimony (Sb) doped SnO2 showed unique electrical and chemical properties, since the introduction of Sb ions leads to the creation of a new shallow band level and of oxygen vacancies acting as donors in SnO2. Although low-doped SnO2:Sb demonstrated an improvement of the sensing performance compared to pure SnO2, there is a lack of investigation on this material. To fill this gap, we focused this work on the study of gas sensing properties of highly doped SnO2:Sb. Morphology, crystal structure and elemental composition were characterized, highlighting that Sb doping hinders SnO2 grain growth and decreases crystallinity slightly, while lattice parameters expand after the introduction of Sb ions into the SnO2 crystal. XRF and EDS confirmed the high purity of the SnO2:Sb powders, and XPS highlighted a higher Sb concentration compared to XRF and EDS results, due to a partial Sb segregation on superficial layers of Sb/SnO2. Then, the samples were exposed to different gases, highlighting a high selectivity to NO2 with a good sensitivity and a limited influence of humidity. Lastly, an interpretation of the sensing mechanism vs. NO2 was proposed.

Wearable Gas Sensor Based on Reticular Antimony-Doped SnO2/PANI Nanocomposite Realizing Intelligent Detection of Ammonia within a Wide Range of Humidity

“…Moreover, the presence of an Sb 3d peak was observed in Figure f, which aligned with the standard value of Sb (3d 3/2 at 540.2 eV), suggesting successful Sb 5+ doping. At low doping concentrations, antimony primarily existed in the form of Sb 5+ , replacing Sn 4+ in the tin oxide lattice. , XPS characterization further verified the valence states of the elements and molecular structures of the composite material.…”

“…At low doping concentrations, antimony primarily existed in the form of Sb 5+ , replacing Sn 4+ in the tin oxide lattice. 34,35 XPS characterization further verified the valence states of the elements and molecular structures of the composite material.…”

Additives in Nanocrystalline Tin Dioxide: Recent Progress in the Characterization of Materials for Gas Sensor Applications

“…The implementation of one or the other option is determined by both fundamental reasons-for example, the difference in the ionic radii of Sn 4+ (0.69 Å) and the additive's cation M n+ -and the synthesis conditions-the method of introducing the additive, the concentration of the additive, and the temperature treatment. Based on the values of the ionic radii of metal cations in an oxygen octahedral environment [82], it can be assumed that the formation of SnO 2 -based solid solutions is possible upon the introduction of Sb 5+ (0.60 Å) [83][84][85][86]; Ti 4+ (0.605 Å) [87][88][89]; Cr 3+ (0.615 Å) [65,90]; Mn 3+ (0.645 Å, high spin) [64,[91][92][93]; Fe 3+ (0.645 Å, high spin) [81,[94][95][96][97]; Co 2+ (0.65 Å, low spin) [63,95,96,[98][99][100][101]; Ni 2+ (0.69 Å) [95,96,[102][103][104][105][106]; Cu 2+ (0.73 Å) [107][108][109]; Zn 2+ (0.745 Å) [110][111][112]; Nb 5+ (0.64 Å) [113][114][115]; and Ru 3+ (0.68 Å) [67,…”

A Theoretical Investigation of Charge Transfer Dynamics from Sensitized Molecule D35CPDT Dye to SnO_2 and TiO_2 Semiconductor

“…𝑆𝑛𝑂 2 is one of the n-type used in dyesensitized solar cells DSSCs [12]. SnO2 is a wide band gap of about 3.6 eV and has chemical and physical steady-state properties at different temperatures [13].…”