Two-Dimensional Material Processing for Flexible Electronics

Two-dimensional (2D) materials, such as graphene, transition-metal dichalcogenides and hexagonal boron nitride, possess atomically thin structures with exceptional electrical, optical and mechanical properties. Their inherent flexibility, high carrier mobility and tunable bandgaps make them ideal for integration into bendable substrates, including plastics, paper and textiles. Key processing strategies encompass liquid-phase exfoliation to produce high-quality dispersions, chemical vapour deposition for wafer-scale films and inkjet printing for mask-free patterning. Supramolecular and covalent functionalisation techniques enhance stability, dispersibility and interflake connectivity, while advanced transfer and abrasion methods facilitate the assembly of heterostructures with preserved electronic quality. Progress in ink formulations, defect engineering and scalable layering has enabled printed transistors, photodetectors and sensors that operate at low voltages, withstand mechanical strain and exhibit long-term stability. These developments underpin emerging applications in wearable health monitors, smart packaging, ubiquitous Internet-of-Things devices and large-area optoelectronics.

Research from Nature Portfolio

Recent studies have demonstrated the fabrication of low-voltage 2D-material transistors on paper substrates by combining patterned MoS2 deposition with inkjet-printed dielectric and contact layers. This approach yields field-effect mobilities exceeding 5 cm2 V−1 s−1 and Ion/Ioff ratios above 104, supporting integrated logic gates and current mirrors in a fully paper-based platform. In parallel, mechanically abraded van der Waals nanocrystal films have been explored to create scalable heterostructures with preserved electronic quality. Abrasion-derived films of layered materials form resistors, capacitors and photovoltaic elements with enhanced performance compared to inkjet-printed dispersions, underscoring a simple, cost-effective route to large-area device fabrication.

Research from all publishers

Multiscale analysis of covalently interconnected MoS2 networks in printed electronics has unveiled that π-conjugated linkers facilitate nearest-neighbour hopping and form percolation pathways, markedly improving charge transport compared to aliphatic counterparts. Density functional calculations corroborate the role of aromatic ligands in enhancing interflake connectivity and device performance in printed field-effect transistors. Separately, fully inkjet-printed thin-film transistors comprising electrochemically exfoliated graphene electrodes, MoS2 semiconducting channels and high-k HfO2 dielectrics have been realised without lithography. The resulting devices achieve current on/off ratios exceeding 105 and field-effect mobilities around 10 cm2 V−1 s−1 at low operating voltages, illustrating the potential of all-inkjet-printed architectures for scalable, low-cost electronics.

Two-Dimensional Material Processing for Flexible Electronics publication trend

The graph below shows the total number of articles in two-dimensional material processing for flexible electronics across all publications each year (not limited to Nature Index journals).

Technical terms

Two-dimensional material: A crystalline substance consisting of one or a few atomic layers with strong in-plane bonds and weak interlayer interactions.

Inkjet printing: A non-contact patterning technique that deposits picolitre droplets of functional inks to form electronic circuits on various substrates.

Liquid-phase exfoliation: A process to separate layered crystals into nanosheets by ultrasonication or shear mixing in a liquid medium, producing colloidal dispersions.

Field-effect transistor (FET): An electronic device in which the current through a semiconducting channel is modulated by an electric field applied via a gate electrode.

Van der Waals heterostructure: A multilayer assembly of different 2D materials held together by van der Waals forces, enabling novel electronic and optical functionalities.

References

1. Unveiling Charge‐Transport Mechanisms in Electronic Devices Based on Defect‐Engineered MoS2 Covalent Networks. Advanced Materials (2023).
2. Low-voltage 2D materials-based printed field-effect transistors for integrated digital and analog electronics on paper. Nature Communications (2020).
3. Heterostructures formed through abraded van der Waals materials. Nature Communications (2020).
4. All inkjet-printed electronics based on electrochemically exfoliated two-dimensional metal, semiconductor, and dielectric. npj 2D Materials and Applications (2022).