Tunneling electron induced luminescence from porphyrin molecules on monolayer graphene
Tunneling electron induced luminescence from porphyrin molecules on monolayer graphene
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单层石墨烯上卟啉分子的隧道电子诱导发光
DOI：
10.1016/j.jlumin.2014.08.033
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发表时间：
2015-01-01
影响因子：
3.6
通讯作者：
Dong, Zhenchao
中科院分区：
文献类型：
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作者：
Geng, Feng;Kuang, Yanmin;Dong, Zhenchao
利用在Ru（0001）上外延生长的石墨烯作为去耦层，研究了不同层数卟啉分子的隧穿电子诱导发光的演化。光发射光谱和光子地图，通过组合的光学设置与扫描隧道显微镜（STM）获得的，表明单层（ML）石墨烯单独的电子去耦效应仍然不足以从第一和第二层卟啉分子产生分子特异性发射。然而，有趣的是，与单层石墨烯上的等离子体发射相比，第一层的等离子体发射增强，但第二层的等离子体发射被抑制。在第三层卟啉处产生固有的分子内荧光。这样的分子厚度比分子直接吸附在金属上的先前报道薄约两个ML。这些观察结果表明，单层石墨烯确实削弱了分子与金属基底之间的相互作用，并有助于降低非辐射衰减速率。(C)2014爱思唯尔有限公司版权所有。
Using epitaxially grown graphene on Ru(0001) as a decoupling layer, we investigate the evolution of tunneling electron induced luminescence from different number of layers of porphyrin molecules. Light emission spectra and photon maps, acquired via a combined optical setup with scanning tunneling microscopy (STM), indicate that the electronic decoupling effect of a monolayer (ML) graphene alone is still insufficient for generating molecule-specific emission from both the 1st- and 2nd-layer porphyrin molecules. Nevertheless, interestingly, the plasmonic emission is enhanced for the 1st-layer but suppressed for the 2nd-layer in comparison with the plasmonic emission on the monolayer graphene. Intrinsic intramolecular molecular fluorescence occurs at the 3rd-layer porphyrin. Such molecular thickness is about two MLs thinner than previous reports where molecules were adsorbed directly on metals. These observations suggest that the monolayer graphene does weaken the interaction between molecule and metal substrate and contribute to the reduction of nonradiative decay rates. (C) 2014 Elsevier B.V. All rights reserved.