Graphene-like Monolayer Yttrium Nitride: A Moderate Semiconductor and Pronounced Electronic Insensitivity to Strain

It is extremely important to explore two-dimensional materials with excellent properties due to their potential applications in future electronic devices. In the present study, a 2D hexagonal YN (h-YN) is predicted based on theoretical calculations. By assessing the phonon spectrum, ab initio molecule dynamics and elastic constants, the h-YN monolayer is proved to own satisfying thermal, dynamic and mechanical stability. Distinguishing from the most reported 2D transition metal mononitrides which exhibit metallic, monolayer h-YN presents a semiconducting characteristic with a indirect bandgap of 1.144 eV. In particular, h-YN presents unsually insensitive responses of electronic structures to tensile or compressive strain due to the valence orbital hybridization. Moderate bandgap together with insensitive electronic responses to strain endow h-YN a promising candidate in future nanoscale electronic devices in high-strain conditions.