https://scholars.lib.ntu.edu.tw/handle/123456789/573481
標題: | TAO-DFT study on the electronic properties of diamond-shaped graphene nanoflakes | 作者: | Huang H.-J., Seenithurai S., Chai J.-D. JENG-DA CHAI |
公開日期: | 2020 | 卷: | 10 | 期: | 6 | 起(迄)頁: | 1-16 | 來源出版物: | Nanomaterials | 摘要: | At the nanoscale, it has been rather troublesome to properly explore the properties associated with electronic systems exhibiting a radical nature using traditional electronic structure methods. Graphene nanoflakes, which are graphene nanostructures of different shapes and sizes, are typical examples. Recently, TAO-DFT (i.e., thermally-assisted-occupation density functional theory) has been formulated to tackle such challenging problems. As a result, we adopt TAO-DFT to explore the electronic properties associated with diamond-shaped graphene nanoflakes with n = 2–15 benzenoid rings fused together at each side, designated as n-pyrenes (as they could be expanded from pyrene). For all the n values considered, n-pyrenes are ground-state singlets. With increasing the size of n-pyrene, the singlet-triplet energy gap, vertical ionization potential, and fundamental gap monotonically decrease, while the vertical electron affinity and symmetrized von Neumann entropy (which is a quantitative measure of radical nature) monotonically increase. When n increases, there is a smooth transition from the nonradical character of the smaller n-pyrenes to the increasing polyradical nature of the larger n-pyrenes. Furthermore, the latter is shown to be related to the increasing concentration of active orbitals on the zigzag edges of the larger n-pyrenes. ? 2020 by the authors. Licensee MDPI, Basel, Switzerland. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087115036&doi=10.3390%2fnano10061236&partnerID=40&md5=7f2b7091a3173d032182bfbd548951cb https://scholars.lib.ntu.edu.tw/handle/123456789/573481 |
ISSN: | 20794991 | DOI: | 10.3390/nano10061236 |
顯示於: | 物理學系 |
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