Developing new thermoelectric materials with high performance can broaden the thermoelectric family and is the key to fulfill extreme condition applications. In this work, we proposed two new high-temperature thermoelectric materials—MgV₂O₅ and CaV₂O₅—which are derived from the interface engineered V₂O₅. The electronic and thermoelectric properties of V₂O₅, MgV₂O₅, and CaV₂O₅ were calculated based on first principles and Boltzmann semi-classical transport equations. It was found that although V₂O₅ possessed a large Seebeck coefficient, its large band gap strongly limited the electrical conductivity, hence hindering it from being good thermoelectric material. With the intercalation of Mg and Ca atoms into the van der Waals interfaces of V₂O₅, i.e., forming MgV₂O₅ and CaV₂O₅, the electronic band gaps could be dramatically reduced down to below 0.1 eV, which is beneficial for electrical conductivity. In MgV₂O₅ and CaV₂O₅, the Seebeck coefficient was not largely affected compared to V₂O₅. Consequently, the thermoelectric figure of merit was expected to be improved noticeably. Moreover, the intercalation of Mg and Ca atoms into the V₂O₅ van der Waals interfaces enhanced the anisotropic transport and thus provided a possible way for further engineering of their thermoelectric performance by nanostructuring. Our work provided theoretical guidelines for the improvement of thermoelectric performance in layered oxide materials.

Large defect-free domains of a hexagonal packed monolayer of silica spheres with the size of 4000 µm² were successfully prepared by dual-speed spin coating. Experimental design and statistical analysis instead of the traditional ‘changing one separate factor at a time’ (COST) approach were employed to guide the implementation of the experiments. With its assistance, the hexagonal-close-packed (HCP) percentage was elevated to 84% in this study. Furthermore, almost all the samples with parameters in the selected ranges possessed more than a 60% HCP percentage. In addition, the optimal values for parameters of the suspension concentration, the first rotation speed, and the spinning time to obtain well-ordered silica spheres arrays were also identified as 30 wt.%, 1000 rpm and 20 s, respectively.