Abstract Using the first-principles density functional theory calculations, we investigate the mechanical and electronic properties of biaxially strained graphitic carbon nitride (g-C3N4). The results show highly isotropic mechanical properties and large linear elasticity of g-C3N4. Moreover, both the Perdew-Burke-Ernzehof (PBE) and Heyd-Scuseria-Ernzerhof (HSE06) band gaps reach the maximum values at 10% strain. The bonding properties are analyzed based on the electronic localization function (ELF). In addition, the photon transition between band gap is weak, suggesting the monolayer g-C3N4 is not suitable for a solar cell material. Enough biaxial strain can induce the spin splitting of g-C3N4, and it is found that the spin-unrestricted band gap of g-C3N4 can be overestimated. This work provides valuable insights for designing the new elastic electronic and spintronic devices based on two-dimensional g-C3N4.

中文翻译：

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双轴应变下石墨氮化碳（g-C3N4）的机械和电子特性

摘要 利用第一性原理密度泛函理论计算，我们研究了双轴应变石墨氮化碳 (g-C3N4) 的机械和电子特性。结果表明，g-C3N4 具有高度各向同性的机械性能和较大的线弹性。此外，Perdew-Burke-Ernzehof (PBE) 和 Heyd-Scuseria-Ernzerhof (HSE06) 带隙在 10% 应变时达到最大值。基于电子定位函数（ELF）分析键合特性。此外，带隙之间的光子跃迁较弱，表明单层 g-C3N4 不适用于太阳能电池材料。足够的双轴应变可以诱导 g-C3N4 的自旋分裂，并且发现 g-C3N4 的自旋无限制带隙可以被高估。