Using the plasmon linewidth to calculate the time and efficiency of electron transfer between gold nanorods and graphene.
Using the plasmon linewidth to calculate the time and efficiency of electron transfer between gold nanorods and graphene.
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DOI：
10.1021/nn404985h
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发表时间：
2013-12-23
期刊：
影响因子：
17.1
通讯作者：
Link S
中科院分区：
文献类型：
--
作者：
Hoggard A;Wang LY;Ma L;Fang Y;You G;Olson J;Liu Z;Chang WS;Ajayan PM;Link S
在无偏压的情况下，我们对单层石墨烯与金纳米棒之间的电子转移进行了定量分析。使用单粒子暗场散射和光致发光光谱获得了均匀的线宽，我们观察到与在石英衬底上的纳米棒相比，金纳米棒在石墨烯上的表面等离子体共振展宽。由于没有光谱等离子激元位移，金纳米棒与石墨烯之间的介电相互作用并不重要，我们将等离子体激元的衰减指定为等离子体激元产生的热电子与作为有效受主的石墨烯之间的电荷转移。对等离子体激元线宽的分析得出的平均电子转移时间为160±30飞秒，否则很难在单粒子灵敏度的时间域中直接测量。与本征热电子衰变和辐射弛豫相比，我们进一步从等离子体激元线宽计算出金纳米棒与石墨烯载体之间的电荷转移效率约为10%。我们的结果对于未来利用金属纳米粒子等离子体和有效的热电子受体进行光捕获以及理解等离子体辅助化学反应中的热电子转移具有重要意义。
We present a quantitative analysis of the electron transfer between single gold nanorods and monolayer graphene under no electrical bias. Using single particle dark-field scattering and photoluminescence spectroscopy to access the homogenous linewidth, we observe broadening of the surface plasmon resonance for gold nanorods on graphene compared to nanorods on a quartz substrate. Because of the absence of spectral plasmon shifts, dielectric interactions between the gold nanorods and graphene are not important and we instead assign the plasmon damping to charge transfer between plasmon-generated hot electrons and the graphene that acts as an efficient acceptor. Analysis of the plasmon linewidth yields an average electron transfer time of 160 ± 30 fs, which is otherwise difficult to measure directly in the time domain with single particle sensitivity. In comparison to intrinsic hot electron decay and radiative relaxation, we furthermore calculate from the plasmon linewidth that charge transfer between the gold nanorods and the graphene support occurs with an efficiency of ~ 10%. Our results are important for future applications of light harvesting with metal nanoparticle plasmons and efficient hot electron acceptors as well as for understanding hot electron transfer in plasmon-assisted chemical reactions.