Chinese technique for making ultrathin metal films named top 10 scientific breakthroughs

A China-developed technique for making ultrathin metal films was recently included in this year's top 10 scientific breakthroughs by the journal Physics World for achieving the world's first single-atom-layer metal materials, highlighting China's leading position in the field.

The study, conducted by the Institute of Physics of the Chinese Academy of Sciences, has pushed the thickness of metal materials to the angstrom scale, a thickness of merely one-millionth of that of a standard A4 paper and one-200,000th the diameter of a human hair.

Since the discovery of graphene in 2004, scientists have created hundreds of two-dimensional materials, all originating from layered crystals. Non-layered metals, which make up 80 percent of the periodic table of elements, were considered nearly impossible to peel into a single atomic layer due to their tightly bonded three-dimensional atomic structures.

To tackle the challenge, the research team pioneered an innovative van der Waals squeezing technique, using molybdenum disulfide as an anvil to compress two-dimensional metals of bismuth, tin, lead, indium, and gallium.

The developed two-dimensional metals offer multiple advantages, such as environmental stability with no performance degradation for over one year, nonbonding interfaces to facilitate the exploration of the materials' intrinsic properties, and higher room-temperature conductivity.

The metals are expected to give rise to macroscopic quantum phenomena, providing core materials for technological innovations in low-power transistors, high-frequency devices, and ultrasensitive detection.

Physics World's annual top 10 list is widely regarded as authoritative. To be selected, an achievement must demonstrate significant scientific importance, advance the frontiers of knowledge, tightly integrate theory and experiment, and attract broad attention from physicists worldwide. This marks the seventh study led by Chinese scientists since the list was established in 2009 by the international professional body Institute of Physics.