The power of computational materials science

The role of quantum mechanical calculations in materials science and technology is becoming increasingly important as it can help tune the properties of new designs in a variety of applications based on a deep and solid understanding of atomic-scale interactions that govern the performance of the final material. 

In an article published in Advanced Materials (Impact Factor = 26), researchers from three different Institutes (ETH-Zürich, Tohoku University, University of Patras) combined state-of-the-art experimental techniques with density functional theory (DFT) calculations to study the different chemo-resistive properties of polymorphs (distinct structural forms of the same compound) of tungsten oxide (WO₃). The crystal phase of this material has been implemented in advanced sensing platforms (including clinical tests for non-invasive metabolic monitoring via skin- and breath-acetone analysis) that have been deployed in diverse contexts.

It was shown that the stronger chemo-resistive response of ε-WO3 is associated to stabilized W(5d)-derived electronic states just below the conduction band minimum upon analyte adsorption. These states are thermally accessible and conduction-relevant, offering an energetically favorable pathway for resistance modulation under operating conditions. The finding opens new opportunities in transducer design strategies that are grounded on electronic structure criteria, because it proves that structural polymorphism does not affect the analyte affinity to the WO₃ substrate but rather it tunes the energetic landscape for electron accommodation.