Enhanced nonlinear absorption and ultrafast carrier dynamics in graphene/gold nanoparticles nanocomposites
Enhanced nonlinear absorption and ultrafast carrier dynamics in graphene/gold nanoparticles nanocomposites
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石墨烯/金纳米粒子纳米复合材料中增强的非线性吸收和超快载流子动力学
DOI：
10.1016/j.carbon.2019.03.054
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发表时间：
2019-07
期刊：
影响因子：
10.9
通讯作者：
Hou Xun
中科院分区：
文献类型：
--
作者：
Yu Yang;Si Jinhai;Yan Lihe;Li Ming;Hou Xun
采用飞秒激光开孔Z扫描方法研究了激光烧蚀法制备的金纳米颗粒/还原氧化石墨烯（AuNPs/rGO）纳米复合材料的非线性光学响应，观察到了增强的非线性吸收效应。利用飞秒时间分辨泵浦-探测技术，研究了该杂化材料的非线性响应机制。在超短激光脉冲激发下，石墨烯的价带（VB）发生漂白，导带（CB）被填充，产生饱和吸收（SA）效应。当用金纳米颗粒修饰时，从石墨烯的CB激发的载流子可以转移到金属的sp带，然后返回到石墨烯的VB。这一过程将在比纯石墨烯中的直接弛豫长得多的时间尺度（250 ps）内发生，从而导致SA效应的增强。利用飞秒时间分辨瞬态吸收光谱进一步证实了激发态载流子的动力学过程，观察到从AuNPs的sp带到石墨烯CB的激发电子的带间弛豫，导致石墨烯CB的进一步填充和SA效应的增强.
The nonlinear optical response of gold nanoparticles/reduced graphene oxide (AuNPs/rGO) nanocomposites prepared by laser ablation method was studied using a femtosecond laser open-aperture (OA) Z-scan method, and an enhanced nonlinear absorption effect was observed. Using the femtosecond time-resolved pump-probe measurements, the nonlinear response mechanism in the hybrid was studied. When graphene was excited by an ultrashort laser pulse, the bleaching of valence band (VB) and the filling of conduction band (CB) took place, causing a saturable absorption (SA) effect. When decorated with gold nanoparticles, the excited carriers from the CB of graphene could transfer to the sp band of the metal before returning to the VB of graphene. This process would take place in a much longer time scale (∼50 ps) than the direct relaxation in pure graphene, causing the enhancement of the SA effect. The excited carrier dynamics were further demonstrated using femtosecond time-resolved transient absorption spectroscopy, and the interband relaxation of the excited electrons from the sp band of AuNPs to the CB of graphene was observed, resulting in the further filling of the CB of graphene and enhancement of the SA effect.
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DOI：
10.1201/9780203912539.ch9
发表时间：
2015
期刊：
--
影响因子：
--
作者：
E. W. Stryland;D. Hagan
通讯作者：
E. W. Stryland;D. Hagan
用氧化石墨烯功能化金属纳米结构薄膜，通过表面增强拉曼光谱对芳香分子进行超灵敏检测
影响因子：
9.5
作者：
Liu, Xiaojuan;Cao, Linyuan;Lu, Lehui
通讯作者：
Lu, Lehui
飞秒激光诱导溶液中碳纳米点尺寸减小：激光能量密度、光斑尺寸和照射时间的影响
影响因子：
3.2
作者：
Vanthan Nguyen;Yan, Lihe;Hou, Xun
通讯作者：
Hou, Xun
影响因子：
3.8
作者：
Zhang, H.;Lu, S. B.;Loh, K. P.
通讯作者：
Loh, K. P.
影响因子：
41.2
作者：
Raccichini, Rinaldo;Varzi, Alberto;Scrosati, Bruno
通讯作者：
Scrosati, Bruno