Cross-linking forming networks and heterostructures

2D-PRINTABLE partners demonstrated the fabrication of cross-linked networks (both homo- and hetero-networks) based on defect-engineering. Chalcogen vacancies in TMDs, such as edge-sulfur vacancies, MoS₂ and WS₂, have been exploited to link adjacent flakes through dithiolated π-conjugated molecules. The synthesized cross-linked hetero-networks have been further characterized by TAS, shedding light on the unique optical characteristics of covalently interconnected networks, such as the suppression of the formation of typical tightly bound interlayer excitons of conventional TMD blends, which promotes faster charge separation. Furthermore, hetero-networks exhibited superior field-effect mobility due to a reduced trap density, resulting from the formation of heterojunctions. This approach for assembling heterostructures from 2DMs inks is versatile and can be extended to other materials, using bidentate linkers tailored to the intrinsic defectivity of 2DMs beyond TMDs.

The full report is available on our website.

EIS tracking over the film growth. (a) Schematic illustration of the 2-electrode electrochemical cell. (b) Schematics of TMDs network acting as a barrier to ionic conductivity with (left) and without BDT as molecular linker (right). Nyquist plots evolution (c) upon BDT treatment between each MoS₂ and WS₂ step and (d) in absence of BDT. (e) R_ct comparison as a function of 2DMs deposition for networks with and without BDT, displayed in blue and purple, respectively.