DFT study on the electronic structure and optical properties of N, Al, and N-Al doped graphene
DFT study on the electronic structure and optical properties of N, Al, and N-Al doped graphene
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DOI：
10.1016/j.apsusc.2018.08.015
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发表时间：
2018-11
影响因子：
6.7
通讯作者：
Xi Zhou;Cuihua Zhao;Guofei Wu;Jian-hua Chen;Yuqiong Li
中科院分区：
文献类型：
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作者：
Xi Zhou;Cuihua Zhao;Guofei Wu;Jian-hua Chen;Yuqiong Li
用第一性原理计算方法研究了纯石墨烯、N掺杂石墨烯、Al掺杂石墨烯和N-Al共掺杂石墨烯的电子结构和光学性质。纯石墨烯是一种零禁带半导体。在N、Al和N-Al掺杂后，能隙被打开。N-Al共掺杂石墨烯的禁带宽度最大，为0.47 eV，其次是Al掺杂石墨烯，为0.40 eV，N掺杂石墨烯为0.21 eV。对于掺N的石墨烯，碳原子失去电子，氮原子获得电子，而碳获得电子，铝原子失去电子。对于N-Al共掺杂的石墨烯，铝原子损失的电子数(2.31e)比掺铝的石墨烯的多(2.27e)，而氮原子得到的电子(−)(−0.76e)比掺N的石墨烯的多(0.27e)。N、Al、N-Al掺杂后，石墨烯的吸收峰变弱，尤其是N、Al掺杂的低频峰。N-Al掺杂石墨烯的吸收曲线与纯石墨烯的吸收曲线相似。然而，N-Al掺杂石墨烯的低频吸收峰相对于纯石墨烯向低能量方向移动，这表明π和π∗之间的跃迁更容易发生，并导致禁带打开。
The electronic structures and optical properties of pure, N-doped, Al-doped, and N-Al co-doped graphenes were studied by the first-principle calculation. The pure graphene is a zero bandgap semiconductor. The energy gaps were opened after N, Al, and N-Al doping. The gap value of N-Al co-doped graphene is the largest, 0.47 eV, then Al-doped graphene, 0.40 eV, and N-doped graphene, 0.21 eV. For N-doped graphene, carbon atom loses electrons, nitrogen atom gains electrons, while carbon gains electrons, aluminum atom loses electrons for Al-doped graphene. For N-Al co-doped graphene, aluminum atom loses a bit more electrons (2.31 e) than that in Al-doped graphene (2.27 e), while nitrogen atom gains a lot more electrons (−0.76 e) than that in N-doped graphene (−0.27 e). After N, Al, N-Al doping, the absorption peaks of graphene become weak, especially low frequency peaks of N and Al doping. The absorption curve of N-Al doped graphene is similar with that of pure graphene. However, the absorption peak of low frequency for N-Al doped graphene shifts to low energy relative to pure graphene, showing that it is easier for the transitions betweenπandπ∗, and lead to the opened gap.