Graphene Nanoribbons: Synthesis and Electronic Properties

Graphene nanoribbons (GNRs) are narrow strips of graphene distinguished by their atomic‐scale width and edge geometry, which together define their electronic band structure and transport characteristics. Unlike bulk graphene, which is semimetallic, GNRs exhibit a finite band gap arising from quantum confinement and edge effects, making them promising for next‐generation electronic and spintronic devices. Two principal fabrication strategies have emerged: top‐down methods, which carve ribbons from larger graphene sheets but often suffer from edge roughness, and bottom‐up chemical synthesis, which assembles molecular precursors in solution or directly on surfaces to achieve atomically precise widths and edge configurations. Edge terminations—commonly zigzag or armchair—critically influence the band gap, charge mobility and magnetic properties. Advances in on‐surface synthesis under ultrahigh vacuum and solution‐phase routes have enabled control over ribbon length, heteroatom incorporation and pore architecture. These developments have unlocked a suite of quantum transport phenomena such as Coulomb blockade and spin‐dependent currents, and have yielded field‐effect and single‐electron transistors with high on/off ratios. Continued refinement of synthetic approaches and device integration is driving GNRs towards practical applications in low-power electronics, quantum information processing and nanoscale sensing.

Research from Nature Portfolio

Recent studies have demonstrated the electrical contacting of individual on-surface synthesized GNRs by integrating single-walled carbon nanotubes as nanoscale electrodes, enabling multigate device architectures that reveal Coulomb blockade, vibrational excited states and Franck–Condon blockade at the single-ribbon level. In parallel, spin-polarized scanning tunnelling microscopy has been employed to map the energy-dependent spin-moment distribution along chiral GNR edges, confirming that electron correlations drive spin splitting in extended π-states and opening avenues for organic magnetic nanodevices. Most recently, a solution-phase approach has yielded porphyrin-fused GNRs with metalloporphyrin units embedded in a fjord-edged backbone, producing ribbons over 100 nm long, an optical band gap near 1.0 eV and local charge mobility exceeding 400 cm2 V–1 s–1. These porphyrin-fused nanoribbons have been incorporated into ambipolar field-effect and single-electron transistors, showcasing controllable electrical and magnetic properties via coordination chemistry.

Graphene Nanoribbons: Synthesis and Electronic Properties publication trend

The graph below shows the total number of articles in graphene nanoribbons: synthesis and electronic properties across all publications each year (not limited to Nature Index journals).

Technical terms

Graphene nanoribbon: A nanometre-wide strip of graphene whose lateral confinement and edge geometry generate a finite electronic band gap.

Bottom-up synthesis: Assembly of GNRs from molecular precursors in solution or on surfaces, enabling atomic precision in width and edge structure.

On-surface synthesis: Formation of GNRs through precursor polymerisation and cyclodehydrogenation on a substrate under ultrahigh vacuum.

Band gap: The energy difference between the valence and conduction bands that determines semiconducting behaviour.

Zigzag/armchair edges: Specific edge terminations of GNRs that govern electronic, magnetic and transport properties.

Coulomb blockade: The suppression of electron transport through a nanoscale system due to quantisation of charge at low temperatures.

Spin-polarization: An imbalance of spin-up versus spin-down electrons in a material, giving rise to magnetic moments.

References

1. Contacting individual graphene nanoribbons using carbon nanotube electrodes. Nature Electronics (2023).
2. Detecting the spin-polarization of edge states in graphene nanoribbons. Nature Communications (2023).
3. Porphyrin-fused graphene nanoribbons. Nature Chemistry (2024).
4. On‐Surface Synthesis of Edge‐Extended Zigzag Graphene Nanoribbons. Advanced Materials (2023).
5. Bottom‐up Solution Synthesis of Graphene Nanoribbons with Precisely Engineered Nanopores. Angewandte Chemie International Edition (2023).