A team of researchers from the Institute of Physics in Zagreb from the Group for Surfaces, Interfaces and 2D Materials, in collaboration with scientists from Elettra Synchrotron Trieste, Shimane University and Institute of Science Tokyo, has provided new insights into the interaction between lithium and borophene – one of the newest members of the family of two-dimensional materials.
Borophene, an atomically thin sheet of boron, has attracted considerable attention because of its unique electronic properties and potential for future applications in nanoelectronics and energy storage. However, little has been known about how the material responds to chemical doping with alkali metals such as lithium, which is important from the fundamental and applicative aspect.
In a study published in ACS Nano, also featured on the front cover of the journal, the researchers combined advanced microscopy and spectroscopy techniques with state-of-the-art theoretical calculations to investigate lithium deposition onto epitaxial borophene on iridium. The experiments revealed that lithium atoms remain on the surface of borophene rather than penetrating beneath it, as commonly occurs in other two-dimensional materials. At the same time, lithium donates a significant amount of electronic charge to the borophene layer, strongly modifying its electronic structure (see Figure 1).
The team discovered that this charge transfer also distorts the borophene lattice (see Figure 2), highlighting the delicate balance that stabilizes the material. Upon heating, part of the lithium desorbs from the surface, while the remaining atoms drive the formation of new boron–lithium–iridium surface structures.
“These findings improve our understanding of how borophene responds to chemical functionalization and provide important guidance for future efforts to engineer its properties,” says Marin Petrović, lead scientist of the study and author of the journal’s front cover.
Beyond advancing fundamental knowledge of two-dimensional boron materials, the work establishes an important benchmark for evaluating borophene in future electronic devices and battery-related technologies.
The paper is available in open access at: doi.org/10.1021/acsnano.6c04291
Journal cover with a featured paper: https://pubs.acs.org/toc/ancac3/20/28