A new two dimensional carbon allotrope TPDH-graphene (Tetra-Penta-Deca-Hexagonal-graphene) belonging to the tetragonal-pentagonal carbon ring family is proposed in this work using density-functional method. The allotrope satisfies all the conditions of structural stability. This allotrope has lower cohesive energy than many existing planar carbon allotropes. It can withstand temperature as high as 1000 K without loosing its structural integrity. However, its electronic structure reflects metallic character due to delocalised p_z orbital near the Fermi level. Further, this mechanically stable elastically anisotropic structure shows directional variation of In-plane Young's modulus and Poisson's ratio. It is stronger than graphene in a particular direction. Moreover, The material can be identified by four characteristic peaks in the electron energy loss spectra within 10 eV energy. It has optical reflectance peaks in the visible range at ∼600 nm yellow colour. Interestingly, some nanoribbons of this material show semimetallic, semiconducting and metallic behaviour. Non-equilibrium Green's function method along with density-functional theory is employed to study the nanodevices made of these nanoribbons. Strong current regulation property and robust negative differential resistance effect with a peak-to-valley ratio 3.3 are observed in two nanodevices making TPDH-graphene an attractive material for use in nanoelectronics.

在这项工作中使用密度泛函方法提出了一种新的二维碳同素异形体TPDH-石墨烯（Tetra-Penta-Deca-Hexagonal-graphene），它属于四角五角碳环家族。同素异形体满足结构稳定性的所有条件。这种同素异形体具有比许多现有的平面碳同素异形体更低的内聚能。它可以承受高达1000 K的温度而不会失去其结构完整性。然而，由于p _z的局域化，其电子结构反映出金属特性费米能级附近的轨道。此外，这种机械稳定的弹性各向异性结构显示面内杨氏模量和泊松比的方向变化。在特定方向上它比石墨烯强。此外，可以通过在10 eV能量以内的电子能量损失谱中的四个特征峰来识别该材料。它在约600 nm的黄色可见范围内具有光反射峰。有趣的是，这种材料的一些纳米带表现出半金属，半导体和金属性能。非平衡格林函数方法与密度泛函理论一起用于研究由这些纳米带制成的纳米器件。峰谷比强的电流调节特性和强大的负差分电阻效应3。