Elucidating Quantum Confinement in Graphene Oxide Dots Based On Excitation-Wavelength-Independent Photoluminescence

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• 作者：Te-Fu Yeh ; Wei-Lun Huang ; Chung-Jen Chung ; I-Ting Chiang ; Liang-Che Chen ; Hsin-Yu Chang ; Wu-Chou Su ; Ching Cheng ; Shean-Jen Chen ; Hsisheng Teng
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：June 2, 2016
• 年：2016
• 卷：7
• 期：11
• 页码：2087-2092
• 全文大小：420K
• 年卷期：0
• ISSN：1948-7185

文摘

Investigating quantum confinement in graphene under ambient conditions remains a challenge. In this study, we present graphene oxide quantum dots (GOQDs) that show excitation-wavelength-independent photoluminescence. The luminescence color varies from orange-red to blue as the GOQD size is reduced from 8 to 1 nm. The photoluminescence of each GOQD specimen is associated with electron transitions from the antibonding π (π*) to oxygen nonbonding (n-state) orbitals. The observed quantum confinement is ascribed to a size change in the sp² domains, which leads to a change in the π*−π gap; the n-state levels remain unaffected by the size change. The electronic properties and mechanisms involved in quantum-confined photoluminescence can serve as the foundation for the application of oxygenated graphene in electronics, photonics, and biology.