Aluminum-Activated Borophene Nanosheets with Enhanced Oxidation Resistance for Nanoelectronic Devices.

Two-dimensional borophene nanosheets are sensitive to oxygen, which has hindered their development and use in scientific research and subsequent applications. Conventional methods of borophene synthesis are based on its epitaxial growth on single-crystal metal substrates by using molecular beam epitaxy (MBE). The electron deficiency of boron atoms in the borophene structure has made the use of metal substrates in the growth process inevitable. Hence, a method to stabilize the borophene sheets for further applications seems necessary. In this work, the oxidation arrangement of Al-activated chemical vapor deposition (CVD) of borophene sheets was investigated via scanning photoemission microscopy (SPEM). This method allows the investigation of oxidation ordering via its high spatial resolution and elemental sensitivity. The results indicate the persistence of the borophene χ₃ (and some β₁₂) phase after exposure to air. The formation of boron oxide is primarily limited to the Al aggregated islands and the edges while maintaining the borophene configuration intact. Our results show that the electronic exchange between the Al aggregates and the interface of boron atoms at the edges of the borophene sheet can prevent the oxidation process and preserve the borophene sheets for long periods. The lower oxidation tendency of the Al-saturated borophene was confirmed via density functional theory calculation, showing a lower oxygen binding energy on Al/borophene compared with that of the metal-free borophene. The oxidation-resistive borophene can be exploited in innovative high-efficiency catalytic, electronic, and sensing devices. [ABSTRACT FROM AUTHOR]