Buckling-induced variations in electronic, thermal, and optical properties of B3C2N3 monolayer: DFT and AIMD computational approaches

Abstract

Density functional theory is employed to study the novel properties of B${}_3$C${}_2$N${}_3$ monolayer to gain a deeper understanding of variation of electronic, thermal, and optical characteristics arising due to buckling effects. The band structure analysis reveals an energy gap reduction of the buckled B${}_3$C${}_2$N${}_3$ monolayer, causing a displacement of the band gap from the visible to the infrared range. Moreover, the buckling controls the location of the initially, and finally, direct band gap moving it from the K to the $\Gamma$ point in the B${}_3$C${}_2$N${}_3$ monolayer. The phonon band structure calculations indicate that buckled B${}_3$C${}_2$N${}_3$ monolayers are dynamically stable, while ab-initio molecular dynamics simulations, AIMD, evaluate and confirm the thermal stability of both flat and buckled B${}_3$C${}_2$N${}_3$ monolayers. The buckling phenomenon at low temperatures has no a significant impact on the heat capacity contrary to what happens in the high temperature limit. The optical characteristics of the B${}_3$C${}_2$N${}_3$ monolayer, including refractive index, optical conductivity, static dielectric function, and plasmon frequency, are evaluated at different levels of the buckling parameter. The static dielectric function and plasmon frequency are enhanced with the buckling due to the screening of the electron–electron interactions, affecting the collective oscillations. Enhanced screening gives rise higher plasmon frequencies. Tuning the buckling parameter illustrates the significance of buckling as an alternative mechanism for adjusting the performance of B${}_3$C${}_2$N${}_3$ two-dimensional materials for different technological applications such as solar and optoelectronic systems.