High thermal conductivity of orthorhombic BC2N semiconductor: DFT study of electronic, phonon, AIMD, and optical properties

• Published in: Diamond and related materials 2024-10, Vol.148, p.111455, Article 111455
• Main Authors: Abdullah, Nzar Rauf, Azeez, Yousif Hussein, Tang, Chi-Shung, Gudmundsson, Vidar
• Format: Article
• Language: English
• Subjects: BC2N; DFT; Electronic structure; Optical characteristics; Thermal properties
• ISSN: 0925-9635
• DOI: 10.1016/j.diamond.2024.111455

We study the electronic, phonon vibration, thermal, and optical properties of an orthorhombic BC2N structure with two different space groups, PMM2 and P2221. The two phases are identified as BC2N-1 and BC2N-2, respectively. The calculations of the phonon band structure and the molecular dynamic simulations confirm that both phases of BC2N are dynamically and thermally stable. BC2N-2 has a higher symmetry than BC2N-1 causing more degenerate energy levels around the Fermi energy leading a larger band gap of BC2N-2. The BC2N-2 has also more phonon bands as it has more atoms per unit-cell leading to a higher phonon density of states and heat capacity. However, the group velocity of both phases is similar, but the lattice thermal conductivity of BC2N-2 is higher due to its high heat capacity. Furthermore, both phases of BC2N have optical response in the visible light region with different refractive indices and reflectivities. Finally, most of the physical properties of the orthorhombic BC2N are compared to other phases of the structure such as the hexagonal monolayer, the nanoribbon, the nanotube, and the porous tetragonal shape. [Display omitted] •High lattice thermal conductivity is found for orthorhombic BC2N.•Two different phase groups of BC2N give different electronic and optical behaviors.•Orthorhombic BC2N is dynamically and thermally stable.•Group velocity of orthorhombic BC2N does not sensitive for space groups.