Prediction of semiconducting SiP2 monolayer with negative Possion’s ratio, ultrahigh carrier mobilit

• 作 者: Xi Fu Houyong Yang Ling Fu Chaozheng He Jinrong Huo Jiyuan Guo Liming Li
• 机 构: College of Science,Hunan Universtiy of Science and Engineering,Yongzhou 425199,China;Institute of En
• 出 处: 中国化学快报（英文版）
• 发表日期: 2021年3期
• 关键词: First-principles calculation Global optimization method Semiconducting monolayer

Using particle swarm optimization (PSO) methodology for crystal structure prediction, we predicted a novel two-dimensional (2D) monolayer of silicide diphosphorus compound: SiP2, which exhibits good stability as examined via cohesive energy, mechanical criteria, molecular dynamics simulation and all positive phonon spectrum, respectively. The SiP2 monolayer is an indirect semiconductor with the band gap as 1.8484 eV (PBE) or 2.681 eV (HSE06), which makes it more advantageous for high-frequency-response optoelectronic materials. Moreover, the monolayer is a relatively hard auxetic material with negative Possion’s ratios, and also possesses a ultrahigh carrier mobility (1.069×105 cm2 V 1 s 1) which is approximately four times the maximum value in phosphorene and comparable to the value of graphene and CP monolayers. Furthermore, the effects of strains on band structures and optical properties of SiP2 monolayer have been studied, as well as CO2 molecules can be strongly chemically adsorbed on the SiP2 monolayer. A semiconductor-to-metal transition for-9.5% strain ratio case and a huge optical absorption capacity on the order of 106 cm 1 in visible region present. These theoretical findings endow SiP2 Monolayer to be a novel 2D material holding great promises for applications in high-performance electronics, optoelectronics, mechanics and CO2 capturing material.