Ultrafast Dynamics and Nonlinear Optical Responses from sp2- and sp3-Hybridized Domains in Graphene Oxide
Ultrafast Dynamics and Nonlinear Optical Responses from sp2- and sp3-Hybridized Domains in Graphene Oxide
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DOI：
10.1021/jz2008374
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发表时间：
2011-08-18
影响因子：
5.7
通讯作者：
Tian, Jian-Guo
中科院分区：
文献类型：
--
作者：
Liu, Zhi-Bo;Zhao, Xin;Tian, Jian-Guo
利用超快光学差分透射光谱和Z扫描技术研究了单层和少层氧化石墨烯（GO）在不同泵浦强度下的超快弛豫动力学和非线性光学响应。人们发现，来自sp（2）杂交域的具有亚皮秒到皮秒动力学的电荷载流子在低泵浦强度下主导超快响应，例如石墨烯。令人惊讶的是，从sp（3）-杂化域的双光子吸收的瞬态吸收信号的影响变得越来越强的泵浦强度。基于GO在sp（2）畴中具有可饱和吸收和在sp（3）畴中具有双光子吸收的异质超快动力学，可以通过控制GO片上氧化的程度和位置来定制非线性光学响应;这揭示了sp（3）畴在石墨烯光学中的重要作用，并将促进GO在光电子学中的潜在应用。
The ultrafast relaxation dynamics and nonlinear optical response in single- and few-layered graphene oxide (GO) were studied by ultrafast optical differential transmission spectroscopy and Z-scan technique using various pump intensities. It was found that charge carriers with subpicosecond-to-picosecond dynamics from sp(2)-hybridized domains dominate the ultrafast response at low pump intensities, like graphene. Surprisingly, the influence of two-photon absorption from sp(3)-hybridized domains on the transient absorption signal becomes increasingly strong with pump intensities. On the basis of heterogeneous ultrafast dynamics of GO with saturable absorption in sp(2) domains and two-photon absorption in sp(3) domains, the nonlinear optical response can be tailored by manipulation of the degree and location of oxidation on GO sheets; this unravels the important role of sp(3) domains in graphene optics and will facilitate the potential applications of GO in optoelectronics.