Recent technological advancement has led to the development of two-dimensional crystals with potential applications in numerous fields including sensors, electrochemical energy storage, electronics among others. Owing to their excellent properties that enable efficient characterization to adapt to strain changes and defect control, two-dimensional crystals have particularly attracted significant attention of researchers. In a recently published literature, graphene-based two-dimensional crystals have been widely used. Unfortunately, due to poor carrier mobility, poor thermodynamic stability and inadequate band gap, pristine graphene is unsuitable to some applications like electronics. Therefore, alternative ways of enhancing the thermodynamic stability, carrier mobility, and band gap are highly desirable.
Presently, several techniques for enhancing the properties of two-dimensional crystals have been developed. For instance, oxidation and hydrogenation have been successfully used in tuning chemical properties for not only graphene but also borophene sheets. In all the cases, high thermodynamic stability and high carrier mobility were noted. As such, researchers have identified hydrogenation and oxidation technologies as a promising solution for enhancing the performance of two-dimensional materials.
Recently, researchers at the Zhejiang University of Technology led by Professor Xiaojun Hu from the College of Materials Science and Engineering proposed two two-dimensional ternary semiconductors. In particular, they designed hexagonal-BCH and tetragonal-BCH that mainly constituted B, C and H atoms. Their research work is currently published in the research journal, Physical Chemistry Chemical Physics.
In brief, the work was an extension of their initial work that was majorly based on two-dimensional boron-carbon and silicon-carbon binary sheets. They further explored the hydrogenation process which enabled the development of the two new structures. Furthermore, the stability of these materials was investigated through first principle calculations, phonon calculations, and molecular dynamics simulations. Their aim was to develop two-dimensional materials with high stability and carrier mobility as well as a good band gap for high-performance applications.
From the conducted experiments, the authors observed that both the hexagonal-BCH and tetragonal-BCH semiconductors exhibited generally good band gap, electron mobility, and thermodynamic stability. For instance, the band gap was recorded as 2.66 and 2.22 eV for h-BCH and t-BCH respectively. Interestingly, the values recorded such as for carrier mobility were significantly higher than those of synthetic two-dimensional monolayers.
In summary, Zhejiang University of Technology scientists successfully designed two-dimensional h-BCH and t-BCH semiconductors theoretically. Generally, they noted a significant improvement in the thermal, mechanical and dynamic stabilities of the structures. To actualize their study, they further investigated the oxidation and reduction levels for water splitting for the two structures. Remarkably, h-BCH responded well owing to the similarities in the positions for the valence and conduction band edges and the chemical reduction potential. Altogether, the study will pave way for the extension of the two-dimensional family through design and development of more advanced, monolayers for numerous applications.
Fan, D., Lu, S., Chen, C., Jiang, M., Li, X., & Hu, X. (2019). A novel hydrogenated boron–carbon monolayer with high stability and promising carrier mobility. Physical Chemistry Chemical Physics, 21(5), 2572-2577.Go To Physical Chemistry Chemical Physics