Publications by authors named "Aleksander F Piasecki"
The influence of inorganic anions on the photoreactivity and aggregation of titanium dioxide nanoparticles (NPs) was assessed by dosing carbonate, chloride, nitrate, phosphate, and sulfate as potassium salts at multiple concentrations. NP stability was monitored in terms of aggregate morphology and electrophoretic mobility (EPM). Aggregate size and fractal dimension were measured over time by laser diffraction, and the isoelectric point (IEP) as a function of anion and concentration was obtained by measuring EPM versus pH.
View Article and Find Full Text PDFVertical stacking of two-dimensional (2D) crystals has recently attracted substantial interest due to unique properties and potential applications they can introduce. However, little is known about their microstructure because fabrication of the 2D heterostructures on a rigid substrate limits one's ability to directly study their atomic and chemical structures using electron microscopy. This study demonstrates a unique approach to create atomically thin freestanding van der Waals heterostructures-WSe2/graphene and MoS2/graphene-as ideal model systems to investigate the nucleation and growth mechanisms in heterostructures.
View Article and Find Full Text PDFArticle Synopsis
- Tungsten diselenide (WSe2) is a promising two-dimensional material for advanced electronic and optoelectronic devices due to its direct bandgap of 1.65 eV and good transport properties.
- The first scalable synthesis method for large-area mono and few-layer WSe2 was achieved via metal-organic chemical vapor deposition using specific chemical precursors, enabling better control over the synthesis process.
- Optimizing factors like temperature and substrate choice can produce sizable crystalline WSe2 domains, with various microscopy techniques confirming the material's quality and revealing the existence of a pristine van der Waals gap in WSe2/graphene structures.