Non-destructive measurement of photoexcited carrier transport in graphene with ultrafast grating imaging technique
Non-destructive measurement of photoexcited carrier transport in graphene with ultrafast grating imaging technique
复制标题
超快光栅成像技术无损测量石墨烯中光生载流子输运
DOI：
10.1016/j.carbon.2016.05.075
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发表时间：
2016-10-01
期刊：
影响因子：
10.9
通讯作者：
Wang, Yaguo
中科院分区：
文献类型：
--
作者：
Chen, Ke;Yogeesh, Maruthi Nagavalli;Wang, Yaguo
石墨烯在制备超快光电子学方面具有很大的潜力，其中光激载流子的弛豫和输运决定了器件的性能。尽管人们对石墨烯中的超快载流子弛豫进行了深入的研究，但石墨烯中光激发载流子的输运性质却鲜为人知。在这项工作中，我们利用超快光栅成像技术，无创地测量了单层和多层石墨烯中光激发载流子的寿命(tau(R))、扩散系数(D)、扩散长度(L)和迁移率(Mu)。在单层石墨烯中观察到类似于10,000 cm(2)/S的D和类似于120,000 cm(2)/V的u，而在多层石墨烯中这两个峰都急剧下降，表明单层石墨烯的显著输运性质源于其独特的狄拉克-锥能结构。这里测量的光激载流子的迁移率比文献中报道的霍尔场效应迁移率大几倍(
Graphene has great potential for fabrication of ultrafast opto-electronics, in which relaxation and transport of photoexcited carriers determine device performance. Even though ultrafast carrier relaxation in graphene has been studied vigorously, transport properties of photoexcited carriers in graphene are largely unknown. In this work, we utilize an ultrafast grating imaging technique to measure lifetime (tau(r)), diffusion coefficient (D), diffusion length (L) and mobility (mu) of photoexcited carriers in mono-and multi-layer graphene non-invasively. In monolayer graphene, D similar to 10,000 cm(2)/s and mu similar to 120,000 cm(2)/V have been observed, both of which decrease drastically in multilayer graphene, indicating that the remarkable transport properties in monolayer graphene originate from its unique Dirac-Cone energy structure. Mobilities of photoexcited carriers measured here are several times larger than the Hall and Field-Effect mobilities reported in literature (