A novel two-dimensional SiO sheet with high-stability, strain tunable electronic structure, and excellent mechanical properties

Using the structure search of particle swarm optimization (PSO) algorithm combined with density functional theory (DFT), we conduct a systematic two-dimensional (2D) material research on the SiO and discover a P2 monolayer structure. The phonon spectrum shows that the 2D P2 is dynamic-stable under ambient pressure. Molecular dynamics simulations show that 2D P2 can still exist stably at a high temperature of 1000 K, indicating that 2D P2 has application potential in high-temperature environments. The intrinsic 2D P2 structure has a quasi-direct band gap of 3.2 eV. The 2D P2 structure can be transformed into a direct band gap semiconductor by appropriate strain, and the band gap can be adjusted to the ideal band gap of 1.2 eV-1.6 eV for photovoltaic materials. These unique properties of the 2D P2 structure make it expected to have potential applications in nanomechanics and nanoelectronics.