Abstract A recently proposed two-dimensional (2D) carbon allotrope, tetrahex-carbon, draws scientific attention due to its remarkable electronic and mechanical properties. This 2D carbon structure consists of tetragonal and hexagonal rings, and exhibits excellent semiconductor properties including a finite direct band gap and high carrier mobility, suggesting potential applications in semiconductor devices. In this paper, the electronic properties of fluorine/hydrogen adsorbed tetrahex-C was investigated via first-principles density-functional theory calculations. It demonstrates that its band structure can be significantly tuned and could be metallic with dangling bonds from F/H adsorption. With increasing F/H adsorption density, it shows semiconducting behavior and the band gap is widening, mainly due to the sp2-bonded carbon being gradually converted to sp3 hybridization. It was also found that effective masses of charge carriers along the zigzag-direction can largely reduce through adsorption of F/H, leading to potentially enhanced carrier mobility. Tetrahex-C shows prominent anisotropicity and the tunability of effective masses through F/H adsorption is remarkably dependent on the crystal orientation. In addition, it was found that, the work function of the F-adsorbed tetrahex-C increases while electron affinity decreases, compared to the pristine one. However, the H-covered carbon film shows significant reductions of both work function and electron affinity.

中文翻译：

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氟/氢吸附二维四六碳的电子特性：第一性原理研究

摘要 最近提出的二维 (2D) 碳同素异形体四六碳，由于其卓越的电子和机械性能而引起科学界的关注。这种二维碳结构由四方环和六方环组成，表现出优异的半导体性能，包括有限的直接带隙和高载流子迁移率，表明在半导体器件中具有潜在应用。在本文中，通过第一性原理密度泛函理论计算研究了氟/氢吸附四六碳-C 的电子性质。它表明它的能带结构可以显着调整，并且可以是金属的，带有来自 F/H 吸附的悬空键。随着 F/H 吸附密度的增加，它表现出半导体行为，带隙变宽，主要是由于 sp2 键合的碳逐渐转化为 sp3 杂化。还发现沿之字形方向的电荷载流子的有效质量可以通过吸附 F/H 大大减少，从而可能提高载流子的迁移率。Tetrahex-C 显示出显着的各向异性，并且通过 F/H 吸附对有效质量的可调性显着依赖于晶体取向。此外，发现与原始的相比，吸附了 F 的四己基-C 的功函数增加，而电子亲和性降低。 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 然而，H 覆盖的碳膜显示出功函数和电子亲和力的显着降低。导致潜在增强的载流子迁移率。Tetrahex-C 显示出显着的各向异性，并且通过 F/H 吸附对有效质量的可调性显着依赖于晶体取向。此外，发现与原始的相比，吸附了 F 的四己基-C 的功函数增加而电子亲和力降低。然而，H 覆盖的碳膜显示出功函数和电子亲和力的显着降低。导致潜在增强的载流子迁移率。Tetrahex-C 显示出显着的各向异性，并且通过 F/H 吸附对有效质量的可调性显着依赖于晶体取向。此外，发现与原始的相比，吸附了 F 的四己基-C 的功函数增加而电子亲和力降低。然而，H 覆盖的碳膜显示出功函数和电子亲和力的显着降低。