史俊杰
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论文成果
Anomalous Light-Emission and Wide Photoluminescence Spectra in Graphene Quantum Dot: Quantum Confinement from Edge Microstructure
发布时间：2020-06-08点击次数：
影响因子：
0.0
DOI码：
10.1021/acs.jpclett.6b01309
发表刊物：
J. Phys. Chem. Lett.
摘要：
The physical origin of the observed anomalous photoluminescence (PL) behavior, that is, the large-size graphene quantum dots (GQDs) exhibiting higher PL energy than the small ones and the broadening PL spectra from deep ultraviolet to near-infrared, has been debated for many years. Obviously, it is in conflict with the well-accepted quantum confinement. Here we shed new light on these two notable debates by state-of-the-art first-principles calculations based on many-body perturbation theory. We find that quantum confinement is significant in GQDs with remarkable size-dependent exciton absorption/emission. The edge environment from alkaline to acidic conditions causes a blue shift of the PL peak. Furthermore, carbon vacancies are inclined to assemble at the GQD edge and form the tiny edge microstructures. The bound excitons, localized inside these edge microstructures, determine the anomalous PL behavior (blue and UV emission) of large-size GQDs. The bound excitons confined in the whole GQD lead to the low-energy transition.
论文类型：
期刊论文
学科门类：
理学
一级学科：
物理学
卷号：
7
页面范围：
2888-2892
是否译文：
否
发表时间：
2016-07-13
收录刊物：
SCI
附件：