Ultra-Clean Angstroporous Monolayer Amorphous Carbon Yields High Precision Proton Beam

Angstrom-scale polygonal rings in monolayer amorphous carbon (MAC) not only tailor its electronic and mechanical properties, but also endow the atomically thin membrane material with diverse angstrom pores for precise regulation of the subatomic species separation and transport, crucial for technological advances across various fields including catalysis, energy devices, and medical applications. However, the lack of industrial-scale synthesis route of intrinsic MAC has severely hindered the progress to harness their versatile angstrom polygons and properties for technological applications that are not offered by the state-of-the-art graphene or bulk amorphous materials. Herein, we report an industry-compatible disorder-to-disorder (DTD) synthetic approach to achieve wafer-scale intrinsic ultra-clean MAC (UC-MAC) within seconds-timescale, featuring optimized angstrom polygons without detectable metal contamination and nano-sized pores. Contrary to metal-contaminated MAC, angstroporous UC-MAC enables not only atomic-scale characterization of its intrinsic electronic properties, but also serve as an angstroporous membrane material, enabling the splitting of high-flux H2+ ions into a high-precision proton beam with minimal detrimental fragment proton scattering events to date, about twice and 40 times less than those from graphene and commercial carbon thin films, respectively. The membrane with minimum possible material thickness that can yield a highly sharpened proton beam with accurately modulated beam current is desired for proton therapy, especially for non-invasive tumor treatment.