Theoretical dissection of superconductivity in two-dimensional honeycomb borophene oxide B 2 O crystal with a high stability

Atomically thin borophene has recently been synthesized experimentally, significantly enriching the boron chemistry and broadening the family of two-dimensional (2D) materials. Recently, oxides of 2D materials have been widely investigated for next-generation electronic devices. Based on the first-principles calculations, we predict the existence of the superconductivity in honeycomb borophene oxide (B2O), which possesses a high stability and could be potentially prepared by intrinsically incorporating oxygen into the recently synthesized borophene. The mechanical, electronic, phonon properties, as well as electron–phonon coupling of metallic B2O monolayer, have been systematically scrutinized. Within the framework of the Bardeen–Cooper–Schrieffer theory framework, the B2O monolayer exhibits an intrinsic superconducting feature with a superconducting transition temperature (Tc) of ~10.3 K, higher than many 2D borides (0.2–7.8 K). Further, strain can be utilized to tune the superconductivity with the optimal Tc of 14.7 K under a tensile strain of 1%. The superconducting trait mainly originates from the out-of-plane soft-mode vibrations of the system, which are significantly enhanced via the light O atoms’ incorporation compared to other 2D metal-boride superconductors. This strategy would open a door to design 2D superconducting structures via the participation of light elements. We believe our findings greatly bloom the 2D superconducting family and pave the way for future nanoelectronics.