First-principles study of the impact of chemical doping and functional groups on the absorption spectra of graphene
First-principles study of the impact of chemical doping and functional groups on the absorption spectra of graphene
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DOI：
10.1088/1361-6641/ac4406
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发表时间：
2021-12
影响因子：
1.9
通讯作者：
Iyyappa Rajan Panneerselvam;Pranay Chakraborty;Qiong Nian;Y. Lu;Yi-Hsien Liao;Yan Wang
中科院分区：
文献类型：
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作者：
Iyyappa Rajan Panneerselvam;Pranay Chakraborty;Qiong Nian;Y. Lu;Yi-Hsien Liao;Yan Wang
先进材料的电子能带结构及其相关性质(如光学)的合理设计一直是光电子学、太阳能海水淡化、先进制造技术等领域的关键应用的挑战。在本工作中，我们利用第一性原理计算，研究了通过缺陷工程，即化学掺杂和氧化来调节石墨烯吸收光谱的前景。我们的计算分析表明，用单羟基和单羧酸对石墨烯进行官能化并不能在石墨烯中打开带隙。然而，虽然单一的环氧化物官能化成功地打开了石墨烯的带隙并增加了吸收率，但其他光学性质，如反射、透射率和介电常数却发生了显著的变化。硼和氮的掺杂分别导致p型和n型掺杂，而氟掺杂或单碳原子空位不能在石墨烯中产生显著的带隙。通过严格考虑自旋极化效应，我们发现钛、锆和氦的掺杂可以通过费米能级附近的诱导平带以及Dirac锥的坍塌在石墨烯中产生带隙。此外，硅、锗和锡的掺杂也有效地改善了薄膜的光学特性。我们的工作对未来石墨烯用于激光和光学加工的实验工作具有重要意义。
The rational design of the electronic band structures and the associated properties (e.g. optical) of advanced materials has remained challenging for crucial applications in optoelectronics, solar desalination, advanced manufacturing technologies, etc. In this work, using first-principles calculations, we studied the prospects of tuning the absorption spectra of graphene via defect engineering, i.e. chemical doping and oxidation. Our computational analysis shows that graphene functionalization with single hydroxyl and carboxylic acid fails to open a band gap in graphene. While single epoxide functionalization successfully opens a bandgap in graphene and increases absorptivity, however, other optical properties such as reflection, transmission, and dielectric constants are significantly altered. Boron and nitrogen dopants lead to p- and n-type doping, respectively, while fluorine dopants or a single-carbon atomic vacancy cannot create a significant bandgap in graphene. By rigorously considering the spin-polarization effect, we find that titanium, zirconium, and hafnium dopants can create a bandgap in graphene via an induced flat band around the Fermi level as well as the collapse of the Dirac cone. In addition, silicon, germanium, and tin dopants are also effective in improving the optical characteristics. Our work is important for future experimental work on graphene for laser and optical processing applications.