Advances in 2D Material Printing Enable High-Performance Heterostructures
Published November 6, 2024
Overcoming Challenges in Vertical Heterostructure Fabrication
Researchers involved with the Graphene Flagship’s 2D-PRINTABLE project have recently demonstrated notable progress in the fabrication of printed heterostructures. These vertical architectures, offering shorter channel lengths compared to planar designs, promise reduced channel resistance and improved control over metal-semiconductor interfaces. However,creating high-quality,ultrathin heterostacks has been hindered by defects like pinholes in 2D materials and solvent-induced re-dispersion during multilayer deposition.
Optimized Fabrication strategies for Enhanced Performance
The 2D-PRINTABLE project has developed optimized fabrication strategies, successfully demonstrated through the creation of metal-insulator-metal (MIM) capacitors and metal-semiconductor-semiconductor-semiconductor-metal (MSSSM) light-emitting diodes (LEDs). Using electrochemically exfoliated molybdenum disulfide (MoS₂) nanosheets as a model material, researchers achieved tunable film thickness simply by adjusting the number of coating cycles.
A key innovation is the implementation of an orthogonal solvent strategy. This approach carefully selects solvents for each layer to minimize the re-dispersion of previously deposited materials, thereby preserving interface quality. Furthermore, the incorporation of other nanomaterials or polymeric semiconductors – such as poly-TPD or zinc oxide (ZnO) nanoparticles – creates seamless networks that effectively block pinholes and prevent unwanted metal diffusion through the 2D material surface.
