Evidence of a two-dimensional nitrogen crystalline structure on silver surfaces

TL;DR

This paper provides experimental evidence of a two-dimensional nitrogen crystalline structure, called nitrogene, formed on silver surfaces, revealing its atomic arrangement and potential electronic properties for advanced applications.

Contribution

First experimental synthesis and characterization of nitrogene-like 2D nitrogen structure on silver surfaces using ion-beam-assisted epitaxy.

Findings

Nitrogene adopts a puckered honeycomb lattice structure.

Predicted band gap of up to 7.5 eV for nitrogene.

Potential applications in ultraviolet optoelectronics and high-k dielectrics.

Abstract

Nitrogen, the most abundant element in Earth's atmosphere, exists as a diatomic gas under standard temperature and pressure. In the two-dimensional (2D) limit, atomically thin nitrogen, termed nitrogene, has been theoretically predicted to form crystalline materials with various polymorphic configurations, exhibiting diverse chemical and physical properties. However, the synthesis of nitrogene has remained elusive due to the strong nitrogen-nitrogen triple bonds. Here, we report experimental evidence of the formation of nitrogen-based crystalline structures compatible with nitrogene on silver surfaces via ion-beam-assisted epitaxy. Through a combination of scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and first-principles calculations, we demonstrate that the nitrogene-like structure adopts a puckered honeycomb lattice. Notably, our calculations predict a nitrogene band gap of up to 7.5 eV, positioning it as a promising candidate for ultraviolet optoelectronic devices and high-k dielectric applications.