Phononic Stability Analysis of Two-Dimensional Carbon Nitride Monolayers

Abstract: In this study we examined the structural, dynamical stability and electronical properties of carbon nitrides monolayers as C6N6 and C6N8. We found that buckled form of C6N8 monolayer is dynamically stable instead of planar C6N8, which is many times studied in the literature. While planar C6N8 has negative optical phonon modes, with proper created buckling in the structure can dissappear these imaginarities and makes the system dynamically stable. This buckled C6N8 has 2.05 eV direct band gap, which falls in the visible region. Other investigated carbon nitride is C6N6 and as is known in the literature planar C6N6 monolayer is stable, while created buckling results instability for the structure. We believe that with this study, confliction on the stability of carbon nitride structures will annihilate and investigation can focus on the planar C6N6 and buckled C6N8 monolayers