The 2D-PRINTABLE partners have successfully achieved a significant milestone in nanosheet characterization. For nanosheets produced via sonication or shear-assisted liquid-phase exfoliation, it is now possible to reliably assess key properties, such as the number of layers and lateral size, using readily accessible spectroscopic techniques like optical extinction spectroscopy. In these cases, quantitative metrics have been established—now enhanced by automated analysis that correlates spectroscopic profiles with average nanosheet layer number and lateral dimensions.
However, for nanosheets exfoliated electrochemically (EE) or chemically (CE), such metrics had not been developed due to the variability in nanosheet dimensions, doping levels, and potential transitions to different polytypes. To address this, the 2D-PRINTABLE partners have advanced the understanding of optical spectra in these nanosheets, identifying key spectral fingerprints associated with defectiveness, doping, and nanosheet dimensions.
As part of the systematic studies within the project, the partners first focused on EE-MoS₂ (model material), detecting spectral changes related to doping by manipulating surface adsorbates on the same sample. This allowed the identification of doping-specific spectral signatures in EE-MoS₂. Simultaneously, a range of samples with varying nanosheet dimensions was produced by modifying production conditions. By integrating these studies with dimensional analysis, the partners have pinpointed which spectral features are primarily sensitive to layer number and less influenced by doping.
