Theoretical insights into tunable optical and electronic properties of graphene quantum dots through phosphorization
Theoretical insights into tunable optical and electronic properties of graphene quantum dots through phosphorization
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通过磷化对石墨烯量子点可调光学和电子特性的理论见解
DOI：
10.1016/j.carbon.2019.09.009
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发表时间：
2019-12-01
期刊：
影响因子：
10.9
通讯作者：
Dong, Lifeng
中科院分区：
文献类型：
--
作者：
Feng, Jianguang;Guo, Qian;Dong, Lifeng
掺杂杂原子或与特定基团形成共价键是修饰石墨烯量子点光学和电子特性的有效途径。本文利用密度泛函理论（DFT）和时变DFT （TD-DFT）研究了五种磷(P)键构型（即C2P、C2PO、C2PO2、C3P和C3PO）对GQDs光学和电子性质的影响。计算了在不同位置掺杂不同P键构型的GQDs的光学吸收光谱、HOMO-LUMO间隙和激发态，揭示了电子跃迁过程。由于第三空轨道的可用性，可以有各种立体化学和成键。结果表明，不同几何构型的P键构型对掺杂GQDs的光谱有不同的影响，C2PO2和C3PO构型中P=O双键的存在可以在P掺杂GQDs中诱发多个吸收峰。当P具有sp(3)杂化时，计算得到的HOMO-LUMO间隙减小较大。激发态分析表明，四面体p掺杂对p掺杂GQDs电子结构的影响更为明显，而锥体p掺杂GQDs在吸收过程中具有明显的电荷转移能力。(C) 2019 Elsevier Ltd.版权所有。
Doping heteroatoms or covalent bonding with specific groups is an effective route to modify optical and electronic properties of graphene quantum dots (GQDs). In this work, effects of five phosphorous (P) bonding configurations (i.e., C2P, C2PO, C2PO2, C3P, and C3PO) on optical and electronic properties of GQDs are investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT). Optical absorption spectra, HOMO-LUMO gaps, and excited states of GQDs doped with different P bonding configurations at various locations are calculated to reveal electron transition processes. Due to the availability of vacant third orbitals,. can have various stereochemistry and bonding. It is demonstrated that P bonding configurations with different geometrical configurations have various influences on the spectra of doped GQDs, and the existence of P=O double bond in C2PO2 and C3PO configurations can induce multiple absorption peaks in P-doped GQDs. The calculated HOMO-LUMO gap has a larger gap reduction when P exhibits the sp(3) hybridization. According to excited state analysis, P-doping with tetrahedral-like configurations has more evident effect on electronic structure of P-doped GQDs, while pyramidal-like configurations have noticeable charge transfer ability in the absorption process. (C) 2019 Elsevier Ltd. All rights reserved.