Zhang Shunhong, Zhou Jian, Wang Qian, Chen Xiaoshuang, Kawazoe Yoshiyuki, Jena Puru
Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China; Collaborative Innovation Center of Inertial Fusion Sciences and Applications, Ministry of Education, Beijing 100871, China; Department of Physics, Virginia Commonwealth University, Richmond, VA 23284;
Department of Physics, Virginia Commonwealth University, Richmond, VA 23284;
Proc Natl Acad Sci U S A. 2015 Feb 24;112(8):2372-7. doi: 10.1073/pnas.1416591112. Epub 2015 Feb 2.
A 2D metastable carbon allotrope, penta-graphene, composed entirely of carbon pentagons and resembling the Cairo pentagonal tiling, is proposed. State-of-the-art theoretical calculations confirm that the new carbon polymorph is not only dynamically and mechanically stable, but also can withstand temperatures as high as 1000 K. Due to its unique atomic configuration, penta-graphene has an unusual negative Poisson's ratio and ultrahigh ideal strength that can even outperform graphene. Furthermore, unlike graphene that needs to be functionalized for opening a band gap, penta-graphene possesses an intrinsic quasi-direct band gap as large as 3.25 eV, close to that of ZnO and GaN. Equally important, penta-graphene can be exfoliated from T12-carbon. When rolled up, it can form pentagon-based nanotubes which are semiconducting, regardless of their chirality. When stacked in different patterns, stable 3D twin structures of T12-carbon are generated with band gaps even larger than that of T12-carbon. The versatility of penta-graphene and its derivatives are expected to have broad applications in nanoelectronics and nanomechanics.
一种二维亚稳态碳同素异形体——五边形石墨烯被提出，它完全由碳五边形组成，类似于开罗五边形镶嵌图案。最新的理论计算证实，这种新型碳多晶型不仅在动力学和力学上是稳定的，而且能够承受高达1000K的温度。由于其独特的原子构型，五边形石墨烯具有异常的负泊松比和超高的理想强度，甚至优于石墨烯。此外，与需要功能化以打开带隙的石墨烯不同，五边形石墨烯具有高达3.25eV的固有准直接带隙，接近氧化锌和氮化镓的带隙。同样重要的是，五边形石墨烯可以从T12-碳中剥离出来。当卷起来时，它可以形成基于五边形的纳米管，无论其手性如何，这些纳米管都是半导体。当以不同模式堆叠时，会产生T12-碳的稳定三维孪晶结构，其带隙甚至比T12-碳的带隙更大。五边形石墨烯及其衍生物的多功能性有望在纳米电子学和纳米力学中得到广泛应用。
