Ultraclean monolayer amorphous carbon yields a high-precision proton beam
Source abstract
Abstract
Ångström-scale polygonal rings in monolayer amorphous carbon (MAC) enhance its electronic and mechanical properties while providing unique ångström pores for precise subatomic species separation, essential for advancements in catalysis, energy and medicine. However, the absence of an industrial-scale synthesis method for intrinsic MAC has limited its technological applications compared with graphene and bulk amorphous materials. Herein, we report an industry-compatible disorder-to-disorder synthesis approach to achieve wafer-scale ultraclean MAC (UC-MAC) within a timescale of seconds, featuring optimized ångström polygons without detectable metal contamination, and nanosized pores. In contrast to metal-contaminated MAC, UC-MAC allows atomic-scale characterization of intrinsic electronic properties and functions as an ångström-scale membrane, facilitating the splitting of high-flux H2+ ions into a high-precision proton beam with minimal detrimental fragment-proton scattering events, about half and 40 times less than those from single-crystal graphene and commercial carbon thin films, respectively. The minimum possible membrane material thickness that can yield a highly sharpened proton beam with accurately modulated beam current is desired for proton therapy.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Ion-surface interactions and analysis · Diamond and Carbon-based Materials Research · X-ray Spectroscopy and Fluorescence Analysis
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (46)
Show source-provided references
1. Novoselov, K. S. et al. Electric field effect in atomically thin carbon films. Science 306, 666–669 (2004).10.1126/science.1102896 ↗
2. Toh, C.-T. et al. Synthesis and properties of free-standing monolayer amorphous carbon. Nature 577, 199–203 (2020).10.1038/s41586-019-1871-2 ↗
3. Tian, H. et al. Disorder-tuned conductivity in amorphous monolayer carbon. Nature 615, 56–61 (2023).10.1038/s41586-022-05617-w ↗
4. Bai, X. et al. Nitrogen-doped amorphous monolayer carbon. Nature 634, 80–84 (2024).10.1038/s41586-024-07958-0 ↗
5. Hong, S. et al. Ultralow-dielectric-constant amorphous boron nitride. Nature 582, 511–514 (2020).10.1038/s41586-020-2375-9 ↗
6. Kim, K. et al. Ultralow-k amorphous boron nitride film for copper interconnect capping layer. IEEE Trans. Electron Devices 70, 2588–2593 (2023).10.1109/TED.2023.3258403 ↗
7. Kim, M. et al. 2D materials in the display industry: status and prospects. Adv. Mater. 35, 2205520 (2023).10.1002/adma.202205520 ↗
8. Wang, J. et al. Cascaded compression of size distribution of nanopores in monolayer graphene. Nature 623, 956–963 (2023).10.1038/s41586-023-06689-y ↗
9. Sun, P. et al. Limits on gas impermeability of graphene. Nature 579, 229–232 (2020).10.1038/s41586-020-2070-x ↗
10. Griffin, E. et al. Proton and Li-ion permeation through graphene with eight-atom-ring defects. ACS Nano 14, 7280–7286 (2020).10.1021/acsnano.0c02496 ↗
11. Wahab, O. et al. Proton transport through nanoscale corrugations in two-dimensional crystals. Nature 620, 782–786 (2023).10.1038/s41586-023-06247-6 ↗
12. Sun, P. et al. Exponentially selective molecular sieving through angstrom pores. Nat. Commun. 12, 7170–7176 (2021).10.1038/s41467-021-27347-9 ↗
13. Huang, J.-K. et al. High-κ perovskite membranes as insulators for two-dimensional transistors. Nature 605, 262–267 (2022).10.1038/s41586-022-04588-2 ↗
14. Fanchini, G., McCauley, J. W. & Chhowalla, M. Behavior of disordered boron carbide under stress. Phys. Rev. Lett. 97, 035502 (2006).10.1103/PhysRevLett.97.035502 ↗
15. Joo, W.-J. et al. Realization of continuous Zachariasen carbon monolayer. Sci. Adv. 3, e1601821 (2017).10.1126/sciadv.1601821 ↗
16. Koga, K., Tanaka, H. & Zeng, X. First-order transition in confined water between high-density liquid and low-density amorphous phases. Nature 408, 564–567 (2000).10.1038/35046035 ↗
17. Thomas, S. An industry view on two-dimensional materials in electronics. Nat. Electron. 4, 856–857 (2021).10.1038/s41928-021-00690-x ↗
18. Gao, L. et al. Face-to-face transfer of wafer-scale graphene films. Nature 505, 190–194 (2014).10.1038/nature12763 ↗
19. Chen, T.-A. et al. Wafer-scale single-crystal hexagonal boron nitride monolayers on Cu(111). Nature 579, 219–223 (2020).10.1038/s41586-020-2009-2 ↗
20. Wan, Y. et al. Wafer-scale single-orientation 2D layers by atomic edge-guided epitaxial growth. Chem. Soc. Rev. 51, 803–811 (2022).10.1039/D1CS00264C ↗
21. Liu, D. et al. Raman enhancement on ultraclean graphene quantum dots produced by quasi-equilibrium plasma-enhanced chemical vapor deposition. Nat. Commun. 9, 193 (2018).
22. Lin, H. et al. Growth of environmentally stable transition metal selenide films. Nat. Mater. 18, 602–607 (2019).10.1038/s41563-019-0321-8 ↗
23. Shi, L. Challenges remain for 2D semiconductor growth. Nat. Nanotechnol. 19, 145 (2024).10.1038/s41565-024-01610-8 ↗
24. Huang, P. Y. et al. Grains and grain boundaries in single-layer graphene atomic patchwork quilts. Nature 469, 389–392 (2011).10.1038/nature09718 ↗
25. Paredes, J., Villar-Rodil, S., Solís-Fernández, P., Martínez-Alonso, A. & Tascon, J. Atomic force and scanning tunneling microscopy imaging of graphene nanosheets derived from graphite oxide. Langmuir 25, 5957–5968 (2009).10.1021/la804216z ↗
26. Lee, J.-H. et al. Wafer-scale growth of single-crystal monolayer graphene on reusable hydrogen-terminated germanium. Science 344, 286–289 (2014).10.1126/science.1252268 ↗
27. Luo, D. et al. Adlayer-free large-area single crystal graphene grown on a Cu(111) foil. Adv. Mater. 31, 1903615 (2019).10.1002/adma.201903615 ↗
28. Wang, M. et al. Single-crystal, large-area, fold-free monolayer graphene. Nature 596, 519–524 (2021).10.1038/s41586-021-03753-3 ↗
29. Liu, Y. et al. Giant enhancement in vertical conductivity of stacked CVD graphene sheets by self-assembled molecular layers. Nat. Commun. 5, 5461 (2014).
30. Yuan, G. et al. Proton-assisted growth of ultra-flat graphene films. Nature 577, 204–208 (2020).10.1038/s41586-019-1870-3 ↗
31. Lu, J., Neto, A. C. & Loh, K. P. Transforming moiré blisters into geometric graphene nano-bubbles. Nat. Commun. 3, 823 (2012).
32. Jiang, J., Wu, P., Liu, Y., Kong, J. & Peng, L.-M. Towards fab-compatible two-dimensional electronics. Nat. Rev. Electr. Eng. 2, 6–8 (2025).10.1038/s44287-024-00125-7 ↗
33. Niu, T., Zhou, M., Zhang, J., Feng, Y. & Chen, W. Growth intermediates for CVD graphene on Cu(111): carbon clusters and defective graphene. J. Am. Chem. Soc. 135, 8409–8414 (2013).10.1021/ja403583s ↗
34. Bortfeld, T. R. & Loeffler, J. S. Three ways to make proton therapy affordable. Nature 549, 451–453 (2017).10.1038/549451a ↗
35. Alonso, J. R., Barlow, R., Conrad, J. M. & Waites, L. H. Medical isotope production with the IsoDAR cyclotron. Nat. Rev. Phys. 1, 533–535 (2019).10.1038/s42254-019-0095-6 ↗
36. Weidner, J. et al. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV. Appl. Radiat. Isot. 70, 2602–2607 (2012).10.1016/j.apradiso.2012.07.006 ↗
37. Winklehner, D. et al. High intensity cyclotrons for neutrino physics. Nucl. Instrum. Methods Phys. Res. A 907, 231–243 (2018).10.1016/j.nima.2018.07.036 ↗
38. Xu, H. et al. Observing electron localization in a dissociating H2+ molecule in real time. Nat. Commun. 8, 15849 (2017).
39. Jun, S. Density-functional study of edge stress in graphene. Phys. Rev. B 78, 073405 (2008).10.1103/PhysRevB.78.073405 ↗
40. Sun, P. et al. Unexpected catalytic activity of nanorippled graphene. Proc. Natl Acad. Sci. USA 120, e2300481120 (2023).10.1073/pnas.2300481120 ↗
41. Hu, S. et al. Proton transport through one-atom-thick crystals. Nature 516, 227–230 (2014).10.1038/nature14015 ↗
42. Zhang, Z. et al. Rosin-enabled ultraclean and damage-free transfer of graphene for large-area flexible organic light-emitting diodes. Nat. Commun. 8, 14560 (2017).
43. Dou, Y., Osipowicz, T. & van Kan, J. A. Breaking the 10 nm barrier using molecular ions in nuclear microprobes. Ultramicroscopy 253, 113812 (2023).10.1016/j.ultramic.2023.113812 ↗
44. Valiev, M. et al. NWChem: a comprehensive and scalable open-source solution for large scale molecular simulations. Comput. Phys. Commun. 181, 1477–1489 (2010).10.1016/j.cpc.2010.04.018 ↗
45. Becke, A. Density-functional thermochemistry. III. The role of exact exchange. J. Chem. Phys. 98, 5648–5652 (1993).10.1063/1.464913 ↗
46. Paszke, A. et al. Automatic differentiation in PyTorch. In NeurIPS Autodiff Workshop (2017).