EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

α-MoO3 is a promising material for use in charge extracting layers within optoelectronic devices, due to its wide gap and deep work-function, characteristics that makes it an established constituent of “hole transporting layers” in last generation solar cells and light emitting diodes. This material possesses a layered structure that make it also suitable for mechanical exfoliation to produce 2D nanosheets, allowing to further tune its electronic properties.
Here, we will report on the synthesis of pristine bulk MoO3 mesostructures and on their liquid phase exfoliation, that produces functional inks of few-layers 2D MoO3. The first process is carried out employing a hydrothermal synthesis, as a green and easily scalable method, while the second, makes use of both shear-mixing and tip sonication in different liquid media, so as to ascertain whether differences emerge in the resulting inks and 2D materials there contained. Characterization through optical/Raman spectroscopy, dynamic light scattering and high-resolution transmission electron microscopy allows to frame the exfoliation process and identify the best conditions. In particular, we found good yields in exfoliated products employing water-based media, which opens nice perspective for the future use of low-toxicity processes for the production of semiconducting building blocks for emerging optoelectronic devices.