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Developing highly efficient semiconductor metal oxide (SMOX) sensors capable of accurate and fast responses to environmental humidity is still a challenging task. In addition to a not so pronounced sensitivity to relative humidity change, most of the SMOXs cannot meet the criteria of real-time humidity sensing due to their long response/recovery time. The way to tackle this problem is to control adsorption/desorption processes, i.e., water-vapor molecular dynamics, over the sensor’s active layer through the powder and pore morphology design. With this in mind, a KIT-5-mediated synthesis was used to achieve mesoporous tin (IV) oxide replica (SnO2-R) with controlled pore size and ordering through template inversion and compared with a sol-gel synthesized powder (SnO2-SG). Unlike SnO2-SG, SnO2-R possessed a high specific surface area and quite an open pore structure, similar to the KIT-5, as observed by TEM, BET and SWAXS analyses. According to TEM, SnO2-R consisted of fine-grained globular particles and some percent of exaggerated, grown twinned crystals. The distinctive morphology of the SnO2-R-based sensor, with its specific pore structure and an increased number of oxygen-related defects associated with the powder preparation process and detected at the sensor surface by XPS analysis, contributed to excellent humidity sensing performances at room temperature, comprised of a low hysteresis error (3.7%), sensitivity of 406.8 kΩ/RH% and swift response/recovery speed (4 s/6 s).

Lanthanum nickelate (LNO) is a perovskite oxide material with metallic conductivity in a wide temperature range which makes it suitable for application as electrode material for thin films. In this paper LNO thin films were prepared by polymerizable complex method from the diluted citrate solutions. Precursor solutions were spin coated onto Si-substrates with amorphous layer of SiO2. Deposited layers were thermally treated from the substrate side with low heating rate (1 °/min) up to 700 °C and finally annealed for 10 hours. Results of AFM and FESEM showed that films are very smooth (Ra = 4 nm), dense, crack-free and with large square-shaped grains (170 nm). According to FESEM and TEM results the obtained four-layered film was only 65 nm thin. EBSD and XRD analyses confirmed polycrystalline microstructure of the films without preferential orientation. It was concluded that the presence of SiO2 layer on Si substrate prevents epitaxial or oriented growth of LNO.

Tin selenides SnSeX (x=1,2) were synthesized from tin and selenium powder precursors by high-energy milling in the planetary ballmill Pulverisette 6 (Fritsch, Germany). The orthorhombic tin selenide SnSe and the hexagonal tin diselenide SnSe2 phases were formed after4 min and 5 min of milling, respectively. Specific surface area of both selenides increased with increasing time of mechanochemicalsynthesis. The particle size distribution analysis demonstrated that the synthesized products contain agglomerated selenide particlesconsisting of numerous idiomorphic tin selenide crystals, measuring from 2 to more than 100 nm in diameter, which were also documentedby TEM. UV-Vis spectrophotometry confirmed that tin selenide particles do not behave as quantum dots.

In this work, we report on the integration of individual BaTiO3 nanorods into simple circuit architectures. Polycrystalline BaTiO3 nanorods were synthesized by electrophoretic deposition (EPD) of barium titanate sol into aluminium oxide (AAO) templates and subsequent annealing. Transmission electron microscopy (TEM) observations revealed the presence of slabs of hexagonal polymorphs intergrown within cubic grains, resulting from the local reducing atmosphere during the thermal treatment. Electrical measurements performed on individual BaTiO3 nanorods revealed resistivity values between 10 and 100 O cm, which is in good agreement with typical values reported in the past for oxygen-deficient barium titanate films. Consequently the presence of oxygen vacancies in their structure was indirectly validated. Some of these nanorods were tested as proof-of-concept humidity sensors. They showed reproducible responses towards different moisture concentrations, demonstrating that individual BaTiO3 nanorods may be integrated in complex circuit architectures with functional capacities. [ABSTRACT FROM AUTHOR]

The full text of the corrigendum is available in the pdf provided. [ABSTRACT FROM AUTHOR]

A polyelectrolyte multilayer (PEM) fabricated by the layer-by-layer (LbL) self-assembly of weak polyions of ployacrylic acid (PAA) and polyallylamine (PAH) was applied as a matrix for the in situ nucleation and growth of pure and Mn-doped ZnS nanocrystallites. The nucleation and growth is initiated by the adsorption and binding of the metal ions to the ionized carboxylic groups of the weak polyions within the matrix, followed by the subsequent precipitation of semiconductor nanocrystallites with Na2S. Transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-vis spectroscopy were employed to establish the growth characteristics of the spherical ZnS nanocrystallites in the polyion matrix. The conformational arrangement of polyion chains induced by variation in the assembly pH is the key parameter that affects the structural and morphological characteristics of ZnS nanocrystallites. Repeating the reaction cycle resulted in an increase in the volume density of ZnS nanoparticles and further growth of the initially formed particles by the Ostwald ripening mechanism. The surface passivation of the ZnS nanocrystallites within the polyion matrix enables the enhanced radiative emission of ZnS composite films in the UV range, whereas by doping the ZnS, nanocrystallites show emission characteristic of the manganese ions in the visible region. [ABSTRACT FROM AUTHOR]