Advancing Vertical Heterostacks with Solution-Processed 2D Nanosheets
Partners of the Graphene Flagship's 2D-PRINTABLE project have recently reported advances in printed heterostructure fabrication.
Compared to planar structures, vertical architectures allow significantly shorter channel lengths, reducing channel resistance and improving control over metal–semiconductor interfacial behaviour. However, achieving high-quality heterostacks at ultrathin active-layer thicknesses remains challenging due to pinhole defects in 2D networks and solvent-induced re-dispersion during multilayer deposition.
2D-PRINTABLE presents optimised fabrication strategies, demonstrated through metal-insulator-metal (MIM) capacitors and metal-semiconductor-semiconductor-semiconductor-metal (MSSSM) LEDs. Electrochemically exfoliated MoS₂ nanosheets were employed as a model material, with film thickness tunable simply by adjusting the number of coating cycles. To preserve interface quality, an orthogonal solvent strategy was implemented, selecting solvents for each layer to minimize re-dispersion of underlying materials. Additionally, other nanomaterials or polymeric semiconductors, such as poly-TPD or ZnO nanoparticles, can be incorporated to form seamless networks that block pinholes and prevent metal diffusion through the 2D surface.
Read the full report on the 2D-PRINTABLE website here.
Author bio
2D-PRINTABLE
2D materials have revolutionised materials science and nanoscience due to their multitude of exceptional physical and chemical properties which enabled ground-breaking applications in optoelectronics, energy, sensing, composites, etc. However, low-cost ways to achieve the superlative properties of individual nanosheets in macroscale samples are crucial to exploiting their full technological potential. 2D-PRINTABLE aims at using sustainable and low-cost liquid exfoliation methods to produce over 40 new 2D materials and to develop printing and liquid-deposition methods to fabricate nanosheet networks and heterostructures with unique properties to enable the production of advanced printed digital devices.