Deep Ultraviolet Photoluminescence of Water-Soluble Self-Passivated Graphene Quantum Dots
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- 作者：Libin Tang ; Rongbin Ji ; Xiangke Cao ; Jingyu Lin ; Hongxing Jiang ; Xueming Li ; Kar Seng Teng ; Chi Man Luk ; Songjun Zeng ; Jianhua Hao ; Shu Ping Lau
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：June 26, 2012
- 年：2012
- 卷：6
- 期：6
- 页码：5102-5110
- 全文大小：692K
- 年卷期：v.6,no.6(June 26, 2012)
- ISSN：1936-086X
文摘
Glucose-derived water-soluble crystalline graphene quantum dots (GQDs) with an average diameter as small as 1.65 nm (5 layers) were prepared by a facile microwave-assisted hydrothermal method. The GQDs exhibits deep ultraviolet (DUV) emission of 4.1 eV, which is the shortest emission wavelength among all the solution-based QDs. The GQDs exhibit typical excitation wavelength-dependent properties as expected in carbon-based quantum dots. However, the emission wavelength is independent of the size of the GQDs. The unique optical properties of the GQDs are attributed to the self-passivated layer on the surface of the GQDs as revealed by electron energy loss spectroscopy. The photoluminescence quantum yields of the GQDs were determined to be 7鈥?1%. The GQDs are capable of converting blue light into white light when the GQDs are coated onto a blue light emitting diode.