Recently synthesized two-dimensional graphene-like material referred to as graphenylene is a semiconductor with a narrow direct bandgap that holds great promise for nanoelectronic applications. The significant bandgap increase can be provided by the strain applied to graphenylene crystal lattice or by using nanoribbons instead of extended layers. In this paper, we present the systematic study of the electronic, optical and thermoelectric properties of graphenylene nanoribbons using calculations based on the density functional theory. Estimating the binding energies, we substantiate the stability of nanoribbons with zigzag and armchair edges passivated by hydrogen atoms. Electronic spectra indicate that all considered structures could be classified as direct bandgap semiconductors. From the calculated dependence of bandgap on nanoribbon width we observe the identical scaling rule for armchair and zigzag graphenylene ribbons. A family-based classification used for the electronic structure of armchair graphene nanoribbons can not be extended to the case of graphenylene ones. The absorption coefficient, optical conductivity, and complex refractive index are calculated by means of the first-principles methods and the Kubo-Greenwood formula. It has been shown that graphenylene ribbons effectively absorb visible-range electromagnetic waves. Due to this absorption, the conductivity is noticeably increased in this range. The transport coefficients and thermoelectric figure of merit are calculated by the nonequilibrium Green functions method. Summarizing the results, we discuss the possible use of graphenylene films and nanoribbons in nanoelectronic devices.

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石墨烯纳米带：来自第一性原理计算的电子、光学和热电特性

最近合成的二维石墨烯类材料称为石墨烯，是一种具有窄直接带隙的半导体，在纳米电子应用中具有广阔的前景。显着的带隙增加可以通过施加到石墨烯晶格的应变或通过使用纳米带代替扩展层来提供。在本文中，我们使用基于密度泛函理论的计算系统地研究了石墨烯纳米带的电子、光学和热电特性。估计结合能，我们证实了具有被氢原子钝化的锯齿形和扶手椅边缘的纳米带的稳定性。电子光谱表明所有考虑的结构都可以归类为直接带隙半导体。根据带隙对纳米带宽度的计算依赖性，我们观察到扶手椅和锯齿形石墨烯带的相同缩放规则。用于扶手椅石墨烯纳米带电子结构的基于家族的分类不能扩展到石墨烯纳米带的情况。吸收系数、光导率和复折射率通过第一性原理方法和 Kubo-Greenwood 公式计算。已经表明，石墨烯带有效地吸收可见范围的电磁波。由于这种吸收，电导率在该范围内显着增加。传输系数和热电品质因数通过非平衡格林函数方法计算。总结结果，