Drastic Change in Photoluminescence Properties of Graphene Quantum Dots by Chromatographic Separation
Drastic Change in Photoluminescence Properties of Graphene Quantum Dots by Chromatographic Separation
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DOI：
10.1002/adom.201400200
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发表时间：
2014-10-01
影响因子：
9
通讯作者：
Matsuda, Kazunari
中科院分区：
文献类型：
--
作者：
Fuyuno, Naoto;Kozawa, Daichi;Matsuda, Kazunari
从基础研究和应用的角度来看，石墨烯量子点（GQD）引起了人们的极大兴趣。光致发光（PL）是 GQD 的有趣特性之一，然而，GQD 中 PL 的机制尚不完全清楚。在本研究中，据报道，通过尺寸排阻高效液相色谱分离的 GQD 的 PL 从紫外光区域到红光区域发生了巨大变化。通过透射电子显微镜图像证实，GQD 通过其整体尺寸的差异进行分离。色谱分离的 GQD 的二维 PL 激发光谱显示在约 330、约 440、约 520 和约 600 nm 处有四个不同的发射峰。分离的 GQD 的主要发光特征显示出取决于 GQD 的总体尺寸的离散变化，表明 PL 变化是由于 GQD 中可用的 sp(2) 片段的密度、形状和尺寸的差异而发生的。
Graphene quantum dots (GQDs) have attracted a great deal of interest from the viewpoints of both fundamental studies and applications. Photoluminescence (PL) is one of the intriguing properties of GQDs, however, the mechanism of the PL in GQDs is not fully understood. In the present study, a drastic change in the PL from UV to red light region is reported among GQDs separated by size-exclusion high performance liquid chromatography. It is confirmed by transmission electron microscopy images that the GQDs are separated by the difference in their overall sizes. Two-dimensional PL excitation spectra of the chromatographically separated GQDs show four distinct emission peaks at approximate to 330, approximate to 440, approximate to 520, and approximate to 600 nm. The dominant luminescence features of the separated GQDs show discrete changes depending on the overall size of GQDs, indicating that the PL variation occurs because of differences in density, shape, and size of sp(2) fragments available in the GQDs.