Physicochemical characterization of a new porous 2D semiconductor carbon allotrope, C: an investigation density functional theory and machine learning-based molecular dynamics.

This study comprehensively characterizes, with suggested applications, a novel two-dimensional carbon allotrope, C, using density functional theory and machine learning-based molecular dynamics. This nanomaterial is derived from naphthalene and bicyclopropylidene molecules, forming a planar configuration with sp hybridization and featuring 3-, 4-, 6-, 8-, and 10-membered rings. The cohesive energy of -7.1 eV per atom, the absence of imaginary frequencies in the phonon spectrum, and the retention of the system's topology after molecular dynamics simulations confirm the structural stability of C. The nanomaterial exhibits a semiconducting behavior with a direct band gap of 0.59 eV and anisotropic optical absorption in the direction. Assuming a complete absorption of incident light, it registers a power conversion efficiency of 13%, demonstrating relatively good potential for applications in solar energy conversion. Excluding the vacuum effect along the non-periodic direction, the planar lattice thermal conductivity reaches ultralow values of 1.90 × 10 W (m K), 0.90 × 10, and 0.59 × 10 for = 300 K, 600 K, and 1000 K, respectively along both and directions. Very close to the Fermi level, the thermoelectric figure of merit () can reach a maximum value of 0.93 at room temperatures along both planar directions, indicating an excellent ability to convert a temperature gradient into electrical power. Additionally, C demonstrates high mechanical strength, with Young's modulus values of 500 GPa and 630 GPa in the and directions, respectively. Insights into the electronic, optical, thermoelectric, and mechanical properties of C reveal its promising capability for energy conversion applications.