Dopant Segregation Analysis on Sb:SnO₂ Nanocrystals

Abstract

The development of reliable nanostructured devices is intrinsically dependent on the description and manipulation of materials’ properties at the atomic scale. Consequently, several technological advances are dependent on improvements in the characterization techniques and in the models used to describe the properties of nanosized materials as a function of the synthesis parameters. The evaluation of doping element distributions in nanocrystals is directly linked to fundamental aspects that define the properties of the material, such as surface‐energy distribution, nanoparticle shape, and crystal growth mechanism. However, this is still one of the most challenging tasks in the characterization of materials because of the required spatial resolution and other various restrictions from quantitative characterization techniques, such as sample degradation and signal‐to‐noise ratio. This paper addresses the dopant segregation characterization for two antimony‐doped tin oxide (Sb:SnO2) systems, with different Sb doping levels, by the combined use of experimental and simulated high‐resolution transmission electron microscopy (HRTEM) images and surface‐energy ab initio calculations. The applied methodology provided three‐dimensional models with geometrical and compositional information that were demonstrated to be self‐consistent and correspond to the systems’ mean properties. The results evidence that the dopant distribution configuration is dependent on the system composition and that dopant atom redistribution may be an active mechanism for the overall surface‐energy minimization.

Mechanistic Aspects in the Formation, Growth and Surface Functionalization of Metal Oxide Nanoparticles in Organic Solvents

“…With increasing reaction times, surface diffusion promoted mass transportation towards the tips of the rods, resulting in dumbbell‐like morphologies, which then fragmented by a detachment process into well‐faceted nanoparticles (Figure b). Also antimony‐doped tin oxide (ATO) nanocrystals synthesized by the benzyl alcohol route present an oriented attachment growth mechanism . In that report, the authors showed that the combined use of surface energy ab initio calculations and Wulff construction could be applied to study the oriented attachment configurations.…”

Transmission electron microscopy analysis of some transition metal compounds for energy storage and conversion

“…Furthermore, the shape and the exposed surface planes can be estimated on the base of projected two-dimensional HRTEM images. Stroppa et al [97] evaluated the three dimensional morphology of Sb doped SnO 2 nanocrystals by combined use of experimental HRTEM image, multislice simulated HRTEM images,…”

High‐Resolution Scanning Transmission Electron Microscopy (HRSTEM) Techniques: High‐Resolution Imaging and Spectroscopy Side by Side

“…[68,69] Apart from HRSTEM tomography [24] and reconstruction of the HAADF-HRSTEM images based on the recorded intensities, [23,25] scanning confocal electron microscopy (SCEM) on STEM mode is a suitable technique for extracting structural information along the imaging zone axis.…”