DFT study of energetics and optoelectronics properties of B, C, and N binary and ternary honeycomb structures

Using the Full Potential Linear Augmented Plane Wave and the pseudo-potential method based on the Density Functional Theory, we investigate the physical properties of two-dimensional (2D) boron nitride, carbon nitride, and boron carbide as well as their ternary system boron carbon nitride (BCN). The structural and optoelectronic properties are determined and discussed in detail with available theoretical and experimental results. We show that the studied physical properties are influenced and tunable by atom concentration. A high concentration of nitrogen (> 50%) disturbs the honeycomb structure of binary and ternary alloys. Additionally, the optoelectronic properties are very sensitive to the amount of boron and nitrogen atoms. The zero bandgap is only conserved for B3C12N3 and B6C6N6 ternary systems. A large bandgap was observed for B9N9 (∼3.9 eV) and a moderate one for B6N12 and B3N15 (∼2 eV). The coexistence of boron, carbon, and nitrogen atoms with different concentrations has important optical properties as they can absorb light in all spectra. However, they have more active absorption in the ultraviolet than visible regions. It is more interesting to use ternary BCN than binary or pristine alloys with tunable optoelectric properties, by varying the nitrogen content in nanodevices.